Ethology and animal behavior

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Language: en

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- In this video we will
begin to explore the field

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of ethology, which is the
study of animal behavior.

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Animal

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behavior.

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And the word itself, ethology,

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it has its roots in the Greek ethos,

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and you also might be familiar
with the word, ethics.

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Ethos, and ethics, you
keep seeing this "eth",

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and it's generally referring
to something's character.

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So you could say this is the study

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of the character of
animals, or in general,

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the behavior of animals.

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And so, let's just first
think of a framework,

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and then we're gonna try to apply it

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to different types of animal
behaviors that we see.

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So first, what is behavior?

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Well, you have some type
of environmental stimulus,

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and it evokes some type of a response,

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some type of a response in the animal.

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And so that is a pretty good definition

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of what behavior, of what
behavior, actually is.

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It's some type of response to
stimulus in an environment.

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The stimulus could be another
animal doing something,

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it could be the temperature, it could be

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the availability of food,
it might be the sun setting,

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who knows, but it's some type of

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response, due to that stimulus.

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Now so, that's the first
thing we're gonna look at,

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the second thing is, well, how
did this behavior come about?

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Was it learned?

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Was it innate?

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So a learned behavior, that animal saw

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something else doing it, and said hey,

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that's a good idea, next
time I see that stimulus,

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or they might not even be
thinking that much about it,

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but somehow they are trained to do it.

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Whenever they did that behavior

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they got rewarded
somehow, or whatever else.

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And the other option is that it's innate,

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the animal would have done it
even if there was no training,

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even if they never had observed it,

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it's in their genetics somehow.

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And the third question we're
going to ask ourselves is,

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well, what's the benefit here?

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What's the benefit here,
especially in a case,

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or in a context of, natural selection.

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Or you know, how did it evolve,
and it should have evolved

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because there's some
benefit, where the members

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of a species that have that
behavior, are selected for.

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So natural selection.

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So now that we have a
little bit of our framework,

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let's think about some animal behaviors.

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Well right over here I have a baby crying,

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and yes, we humans, it's
nice to remind ourselves

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that we are animals, we
should feel very proud

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to be part of this animal kingdom,

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and the behavior here is the child crying,

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and I'll assume this
child is maybe hungry.

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There's many reasons why a baby might cry,

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as you might discover when you
have one, I have three now,

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and I think I have most
of the reasons down.

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But let's say in this context,

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the stimulus is a lack of food.

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Lack of food, and it leads
to the response of crying.

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My two year old just the other day

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was screaming from his
crib, "I want food!"

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And he was kind of crying it out,

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and so that type of behavior,

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where you have lack of
food leading to crying,

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well let's think about it, let's actually

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first think about, what's
the benefit of that?

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It's almost obvious, or
it's almost too obvious.

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Well, if a baby didn't do that,

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then the parents might not
notice that it's hungry,

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and the baby might not get the food,

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might get malnourished, or in
an extreme case, might starve.

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And so by crying, it allows other people,

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say, oh, I need to feed that baby.

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Because a baby isn't able to
go hunt down it's own food,

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it isn't able to, you know, get in the car

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and go buy a sandwich, or go the fridge

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and make itself some cereal,
it needs other people to do it.

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And even the behavior that
I might have as a parent,

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to say oh my god, my son is crying,

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I need to go get him some food!

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That itself is a behavior, the stimulus.

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So there's one stimulus,
the child's hungry,

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leading to the response
of the child crying,

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and then that response is then

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a stimulus to me, to say,
to have the response of,

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oh, let me feed my child
so that they stop crying.

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And so you can imagine it has a

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significant benefit in natural selection.

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You could imagine, and I think
it would be, you wouldn't--

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This probably happened in
our evolutionary history

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far before humans came about, but whatever

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organism you're talking
about, or some animal,

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if the offspring that are
better at making it known

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that they are hungry,
especially if these offspring

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are dependent on their
parents, or something else

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to get them food, well, the ones that cry

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are more likely to get the food,

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and are more likely to survive,

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and pass their DNA on
to future generations.

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And so it makes sense, this
is almost an obvious one,

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why this is favorable from a

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natural selection point of view.

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Another interesting question, and this is,

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you should even ask this
about your own behavior,

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anything that you observe, is,

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is that behavior learned versus innate?

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I haven't run any experiments here,

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but I would guess, my hypothesis is that

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the baby crying in response
to not having food,

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that this is innate, that a baby,

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no one has to teach baby to do this.

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It's somehow programmed into their DNA,

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it's programmed into their brain.

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They don't have to be trained to cry.

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Now, when my five year old cries

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because I didn't give her dessert,

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even though she has
just eaten a full meal,

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I think that might be learned.

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She might be seeing that hey,

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her younger brother tends to
get his way when he cries,

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maybe at five years old,
I should still do that

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even though I really don't have to,

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because I really don't need that dessert,

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that might be learned.

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So once again, it depends on the context,

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and it's a really interesting
thing to think about.

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But lets move on to other
members of the animal world,

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this right here is Pippy,
who works at Khan Academy,

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so Pippy, and when there is food around,

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Pippy acts extra cute, and needy.

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So let's, so the stimulus here is food,

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I guess there's a food theme here,

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maybe I need to be eating some food.

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So maybe when I have a lack of food

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my response is making a video about it,

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but anyway (laughs) when
Pippy is around food,

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acts extra, extra cute,

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and needy.

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And I think all of us have seen

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dogs behave this way,
and it might just seem

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like a simple thing, but this is actually,

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could be a very important
behavior for a dog.

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That, you know, we know what the stimulus,

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and what the response is,
learned versus innate?

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Well, it might be a little bit of both,

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and that's something you'll see

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as you try to analyze more
and more animal behaviors

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is that, well, it's sometimes a continuum.

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Maybe there's an inclination to

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do that behavior, but by learning
it, they get better at it.

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So maybe Pippy would have always

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been somewhat needy around food,

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but when it sees other dogs do it,

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then more likely to learn that behavior.

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And a good example of something that's

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between learned and innate
for human beings is language.

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Now we could do a whole series,

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people dedicate their lives
to studying human language,

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but we think, we have a
lot of reason to believe,

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that humans have an innate bias to

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wanting to communicate, and
having this structured language,

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but you clearly learn
your particular language.

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If human beings were to just,

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if you threw a bunch
of babies on an island,

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which sounds like a very-- it
is a very cruel experiment,

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at some point, they, if they survived,

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they would develop their own language.

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But we also know that if you put a baby

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in the context of someone
speaking English, or French,

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or Hindi, or whatever else, that they

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will actually learn the language.

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So these two things are not
always one way or the other,

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in fact, in most cases,
it's some place in between,

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or it's a combination
of learned, and innate.

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But let's go back to Pippy, why is that a,

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what's the benefit there?

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What's a way of getting food?

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Why would that be selected for?

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Well, the wolves, thousands of years ago,

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that were better at kind
of getting close to humans,

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and acting extra cute, and needy,

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well, they were able to get food,

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they didn't have to
hunt it down themselves.

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And that's actually how dogs came about.

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And we can think of many,
many other examples,

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so this right over here, this
is an opossum playing dead,

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kind of a famous behavior.

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So when there is a threat,
when there is a threat,

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maybe a predator around,
this opossum plays dead.

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Plays dead.

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I would guess, it's
interesting to think about,

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whether it's innate, or
learned, that this is innate.

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That they didn't have
to see another opossum

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do this behavior, in fact, it might,

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they might not even be able to help it

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when their stress hormones
go up high enough,

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they might just turn into
this looking dead state.

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And a lot of times, just to, you know,

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when people say, that's instinct,

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they're often talking
about an innate behavior.

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Instinct.

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It's not saying, oh, well,
maybe if I played dead

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and act really well, that
predator might not come,

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it just can't help it, maybe you know,

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it's hormones go up, and it
just gets into this state.

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And you might say, well,
what's the benefit there?

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It seems like it's easy to catch.

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Well, other animals might not

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like eating things that are dead,

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maybe it has a disease, or whatever else,

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and it doesn't wanna catch it, and so,

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something about the
evolutionary past of opossums,

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or pre-possums, they were selected for,

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the ones that were able to do this

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had a higher chance of not being killed,

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and then passing on their offspring,

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and so we now see this in opossums.

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And once again, we could go through

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a whole range of behaviors,
from hibernation,

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there's also a phenomenon actually that,

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so there's things like hibernation,

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where bears famously
hibernate for the winter.

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Why is that useful?

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Well the stimulus is it's getting cold,

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or in a different part of the season,

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and so they all hibernate.

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Why is that useful?

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Well, it's, they lower
their metabolic rate,

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their need for food when there's
less availability of food.

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And so that also can give you clues

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about why it might have been selected for.

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There's actually a similar,
or form of hibernation,

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I guess you could say, called aestivation,

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aestivation, which I actually
didn't know this word

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until I started looking into this,

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and this is a, and sometimes in the US

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they don't put the "A" in
front, it's just estivation,

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with the "E", but this is a form of

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going into a lower metabolic state

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when things are really hot, or very dry,

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when you don't have availability of water.

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So it's less familiar than
hibernating for the winter,

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but it's another form of getting into

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a lower metabolic state.

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And you might say, well
why does that happen?

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Why would that be selected for?

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Which animals do that?

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And is it innate, is it learned?

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I would propose that
both of these are innate,

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that the animal, most of
the animals that do this

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would do it regardless of
whether they somehow got trained,

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or observed some other animal doing it.


Worked example: Identifying isotopes and ions

WEBVTT
Kind: captions
Language: en

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- [Narrator] An isotope
contains 16 protons,

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18 electrons, and 16 neutrons.

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What is the identity of the isotope?

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And I encourage you to
pause the video and see

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if you can figure it out
and I'll give you a hint,

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you might want to use
this periodic table here.

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All right, so I'm assuming
you've had a go at it.

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So, an element is defined by the number

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of protons it has.

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So if someone tells you
the number of protons, you

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should be able to look at
a periodic table and figure

00:00:31.933 --> 00:00:34.321
out what element they are talking about.

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So, because it is 16
protons, well we can go

00:00:38.484 --> 00:00:42.455
right over here to the atomic
number, what has 16 protons,

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well anything that has 16
protons by definition is going

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to be sulfur right over here.

00:00:48.774 --> 00:00:51.656
So I could write a big S.

00:00:51.656 --> 00:00:54.355
Now, the next thing we
might want to think about

00:00:54.355 --> 00:00:58.073
is the mass number of
this particular isotope.

00:00:58.073 --> 00:01:01.675
Remember, an isotope, all
sulfur atoms are going

00:01:01.675 --> 00:01:04.074
to have 16 protons, but
they might have different

00:01:04.074 --> 00:01:05.495
numbers of neutrons.

00:01:05.495 --> 00:01:07.953
So, the sulfurs that have
different number of neutrons,

00:01:07.953 --> 00:01:10.464
those would be different isotopes.

00:01:10.464 --> 00:01:13.944
So, this case we have
16 protons and we have

00:01:13.944 --> 00:01:18.266
16 neutrons, so if you add
the protons plus the neutrons

00:01:18.266 --> 00:01:21.557
together, you're going
to get your mass number.

00:01:21.557 --> 00:01:25.719
So 16 plus 16 is 32.

00:01:25.719 --> 00:01:29.271
Now let's figure out if there's
going to be any charge here.

00:01:29.271 --> 00:01:31.947
Well, the protons have a positive charge.

00:01:31.947 --> 00:01:33.979
The electrons have a negative charge.

00:01:33.979 --> 00:01:36.789
If you have an equal amount
of protons and electrons,

00:01:36.789 --> 00:01:38.689
then you would have no charge.

00:01:38.689 --> 00:01:40.979
But in this case, we have
a surplus of electrons.

00:01:40.979 --> 00:01:44.630
We have two more electrons
than protons and since

00:01:44.630 --> 00:01:48.900
we have a surplus of the
negative charged particles

00:01:48.900 --> 00:01:52.131
we, and we have two
more, we're going to have

00:01:52.131 --> 00:01:56.310
a negative two charge and
we write that as two minus.

00:01:56.310 --> 00:01:59.939
So this is actually an
ion, it has a charge.

00:01:59.939 --> 00:02:03.410
So this is the isotope
of sulfur that has a mass

00:02:03.410 --> 00:02:06.838
number of 32, the protons
plus the neutrons are 32,

00:02:06.838 --> 00:02:09.609
and it has two more electrons
than protons which gives

00:02:09.609 --> 00:02:11.737
it this negative charge.

00:02:11.737 --> 00:02:16.265
Let's do another example
where we go the other way.

00:02:16.265 --> 00:02:20.682
Where we are told, we are
given some information

00:02:20.682 --> 00:02:23.303
about what isotope and
really what ion we're

00:02:23.303 --> 00:02:25.784
dealing with because this
has a negative charge

00:02:25.784 --> 00:02:28.553
and we need to figure out
the protons, electrons,

00:02:28.553 --> 00:02:29.694
and neutrons.

00:02:29.694 --> 00:02:31.693
Well, the first thing that
I would say is, well look,

00:02:31.693 --> 00:02:33.882
they tell us that this is fluorine.

00:02:33.882 --> 00:02:36.621
As soon as you know what
element we're dealing with,

00:02:36.621 --> 00:02:38.721
you know what it's atomic
number is when you look

00:02:38.721 --> 00:02:40.843
at the periodic table and
you can figure out the number

00:02:40.843 --> 00:02:41.676
of protons.

00:02:41.676 --> 00:02:43.780
Remember, your atomic number
is the number of protons

00:02:43.780 --> 00:02:45.783
and that's what defines the element.

00:02:45.783 --> 00:02:48.191
That's what makes this one fluorine.

00:02:48.191 --> 00:02:51.785
So let's go up to the, our periodic table

00:02:51.785 --> 00:02:55.851
and we see fluorine right
over here has an atomic

00:02:55.851 --> 00:02:57.691
number of nine.

00:02:57.691 --> 00:03:02.071
That means any fluorine has nine protons.

00:03:02.071 --> 00:03:04.321
So, let's scroll back down.

00:03:05.159 --> 00:03:07.687
So, must because it is
fluorine, we know we have

00:03:07.687 --> 00:03:09.417
nine protons.

00:03:09.417 --> 00:03:11.407
Now what else can we figure out?

00:03:11.407 --> 00:03:14.119
Well, we know we have a
negative charge right here

00:03:14.119 --> 00:03:17.469
and this is, you can use
as a negative one charge

00:03:17.469 --> 00:03:21.468
and so we have one more
electron than we have protons.

00:03:21.468 --> 00:03:24.458
And so since we have nine
protons, we're going to have

00:03:24.458 --> 00:03:25.680
10 electrons.

00:03:25.680 --> 00:03:27.747
And then finally how many neutrons?

00:03:27.747 --> 00:03:30.657
Well, remember, the
neutrons plus the protons

00:03:30.657 --> 00:03:33.270
add up to give us this mass number.

00:03:33.270 --> 00:03:35.627
So, if you have nine protons,
well how many neutrons

00:03:35.627 --> 00:03:38.028
do you have to add to
that to get to 18, well

00:03:38.028 --> 00:03:39.960
you're going to have
to have nine neutrons.

00:03:39.960 --> 00:03:42.710
Nine plus nine is 18.


Calculating atomic weight

WEBVTT
Kind: captions
Language: en

00:00:00.312 --> 00:00:01.539
- [Instructor] We have, listed here...

00:00:01.539 --> 00:00:04.442
We know that carbon 12 is the most common

00:00:04.442 --> 00:00:07.518
isotope of carbon on Earth.

00:00:07.518 --> 00:00:11.518
98.89% of the carbon
on Earth in carbon 12.

00:00:13.129 --> 00:00:15.176
And we know that, by definition,

00:00:15.176 --> 00:00:18.593
its mass is exactly 12 atomic mass units.

00:00:20.374 --> 00:00:23.075
Now that's not the only
isotope of carbon on Earth.

00:00:23.075 --> 00:00:24.427
There are other isotopes.

00:00:24.427 --> 00:00:28.070
The next most frequent one is carbon 13.

00:00:28.070 --> 00:00:31.987
1.11% of the carbon on Earth is carbon 13.

00:00:32.942 --> 00:00:35.481
And we can experimentally find that

00:00:35.481 --> 00:00:38.648
its mass is 13.0034 atomic mass units.

00:00:41.410 --> 00:00:43.578
So, these numbers that we have here,

00:00:43.578 --> 00:00:46.523
just as a review, these are atomic mass.

00:00:46.523 --> 00:00:48.356
These are atomic mass.

00:00:49.386 --> 00:00:50.984
And so, what we're gonna
think about, in this video,

00:00:50.984 --> 00:00:53.482
is how do they come up with
the atomic weight number

00:00:53.482 --> 00:00:56.800
that they'll give you on a
periodic table like that?

00:00:56.800 --> 00:00:58.300
So, atomic weight.

00:01:02.244 --> 00:01:04.535
Where does that come from?

00:01:04.535 --> 00:01:07.688
Well, in the video on atomic
weight and on atomic mass,

00:01:07.688 --> 00:01:10.757
we see that the atomic weight
is the weighted average

00:01:10.757 --> 00:01:13.007
of the atomic masses of

00:01:13.007 --> 00:01:16.161
the various isotopes of that element.

00:01:16.161 --> 00:01:18.744
So, to find this roughly 12.01,

00:01:19.766 --> 00:01:22.013
we take the weighted
average of these two things.

00:01:22.013 --> 00:01:23.036
And what do we weight it by?

00:01:23.036 --> 00:01:27.203
We weight it by how common
that isotope actually is.

00:01:28.155 --> 00:01:29.954
So, what we wanna do is,

00:01:29.954 --> 00:01:34.486
we could take 98.89%
and multiply it by 12.

00:01:34.486 --> 00:01:37.103
And I'll rewrite this
percentage as a decimal.

00:01:37.103 --> 00:01:39.436
So it'll be 0.9889 times 12.

00:01:43.285 --> 00:01:47.051
And, to that, we are going to add...

00:01:47.051 --> 00:01:50.801
We are going to add 1.11% times 13.0034.

00:01:54.786 --> 00:01:58.369
So, as a decimal, that's
going to be 0.011.

00:01:59.815 --> 00:02:02.815
That's 1.11% is 0.011, oh, 111.

00:02:07.065 --> 00:02:11.232
And I'm gonna multiply that
times 13.0034 atomic mass units.

00:02:15.164 --> 00:02:16.884
So, what does that give us?

00:02:16.884 --> 00:02:18.602
Let's get our calculator out here.

00:02:18.602 --> 00:02:21.185
So, we are going to have 0.9889

00:02:24.411 --> 00:02:26.828
times 12 is equal to 11.8668.

00:02:29.939 --> 00:02:33.215
And, to that, we are going to add...

00:02:33.215 --> 00:02:36.632
We are going to add 0.0111 times 13.0034.

00:02:45.946 --> 00:02:47.626
And I know it's going to do
this multiplication first

00:02:47.626 --> 00:02:50.100
because it's a calculator knows
about order of operations.

00:02:50.100 --> 00:02:54.267
And so, that's all going to be,
as you can see, 12.01113774,

00:02:57.057 --> 00:02:59.678
which, if you were to round
to the hundredths place,

00:02:59.678 --> 00:03:03.405
is how this atomic weight was gotten.

00:03:03.405 --> 00:03:04.265
So that's that.

00:03:04.265 --> 00:03:05.098
There you go.

00:03:05.098 --> 00:03:06.966
That's how we calculate atomic weight.

00:03:06.966 --> 00:03:10.633
So, I can write this
as approximately 12.01.

00:03:12.119 --> 00:03:15.229
It's the weighted average
of the atomic masses.

00:03:15.229 --> 00:03:17.153
Now, another thing that
you might want to note is,

00:03:17.153 --> 00:03:21.400
what's the difference between
carbon 12 and carbon 13?

00:03:21.400 --> 00:03:24.833
Carbon 12, this right
over here, is six protons.

00:03:24.833 --> 00:03:26.632
The six protons are what make it carbon,

00:03:26.632 --> 00:03:28.799
so both of these will have six protons.

00:03:28.799 --> 00:03:30.680
And the difference is in the neutrons.

00:03:30.680 --> 00:03:34.860
This right over here has
six neutrons, six neutrons.

00:03:34.860 --> 00:03:35.841
And this, right over here,

00:03:35.841 --> 00:03:39.276
is gonna have one more
neutron, seven neutrons.

00:03:39.276 --> 00:03:42.551
So, when you look at the
difference in atomic mass,

00:03:42.551 --> 00:03:44.844
notice the change is...

00:03:44.844 --> 00:03:48.677
Looks like it's plus
1.0034 atomic mass units.

00:03:49.878 --> 00:03:51.393
So, from this, you can say, "Hey, look,

00:03:51.393 --> 00:03:52.908
if I add a neutron...

00:03:52.908 --> 00:03:54.325
Plus one neutron.

00:03:55.201 --> 00:03:56.470
Plus one neutron.

00:03:56.470 --> 00:03:58.923
It's roughly equal to
an atomic mass unit."

00:03:58.923 --> 00:04:00.683
It's not exactly an atomic mass unit,

00:04:00.683 --> 00:04:03.750
but, roughly speaking,
in a lot of very broad,

00:04:03.750 --> 00:04:05.755
high-level terms, you can kind of view it

00:04:05.755 --> 00:04:08.291
as being very close to
one atomic mass unit.

00:04:08.291 --> 00:04:11.195
And the same thing is true of protons.

00:04:11.195 --> 00:04:13.120
Anyway, hopefully you now
have an appreciation for

00:04:13.120 --> 00:04:15.535
the difference between atomic
mass, which is the mass,

00:04:15.535 --> 00:04:17.296
and atomic weight, which
is the weighted average

00:04:17.296 --> 00:04:21.998
of the various isotopes
of that element on Earth,

00:04:21.998 --> 00:04:23.098
how to calculate it,

00:04:23.098 --> 00:04:25.864
and roughly what the mass of a neutron is.


Eutrophication and dead zones

WEBVTT
Kind: captions
Language: en

00:00:00.021 --> 00:00:02.084
- We're now going to talk about something

00:00:02.084 --> 00:00:03.917
called eutrophication.

00:00:05.773 --> 00:00:07.712
Eutrophication.

00:00:07.712 --> 00:00:09.642
And it comes from, or it's derived from,

00:00:09.642 --> 00:00:11.990
the Greek for well nourished.

00:00:11.990 --> 00:00:16.887
Eu referring to well and
then trophic or trophia,

00:00:16.887 --> 00:00:19.508
referring to nourished, or nourishment.

00:00:19.508 --> 00:00:22.167
And so you might think
that this is a good thing

00:00:22.167 --> 00:00:24.271
but as we'll see over
the course of this video,

00:00:24.271 --> 00:00:26.261
this is really about over-nourishment,

00:00:26.261 --> 00:00:28.048
and over-nourishment to the point

00:00:28.048 --> 00:00:30.256
that it's actually causing very bad things

00:00:30.256 --> 00:00:33.263
to happen in our biosphere.

00:00:33.263 --> 00:00:34.909
So the general idea, we've already talked

00:00:34.909 --> 00:00:37.051
about things like nitrogen and especially

00:00:37.051 --> 00:00:39.306
phosphorous being a rate-limiting factor

00:00:39.306 --> 00:00:40.920
for how fast plants can grow.

00:00:40.920 --> 00:00:42.130
We talked about that in the nitrogen

00:00:42.130 --> 00:00:44.316
and the phosphorous cycle videos.

00:00:44.316 --> 00:00:48.013
And because of that, we humans have added

00:00:48.013 --> 00:00:50.512
a lot of nitrogen and
especially phosphates

00:00:50.512 --> 00:00:53.174
to plants in order to grow them better,

00:00:53.174 --> 00:00:54.901
because we need the plants to live,

00:00:54.901 --> 00:00:56.432
to have more food.

00:00:56.432 --> 00:00:57.978
So what has happened is,

00:00:57.978 --> 00:01:02.284
so let's say that this right
over here is some land.

00:01:02.284 --> 00:01:04.459
And this is, let's say that's a farm,

00:01:04.459 --> 00:01:07.762
right over there on the land
where we're growing our crops.

00:01:07.762 --> 00:01:11.174
So these are all the
crops that we're growing.

00:01:11.174 --> 00:01:14.341
In order to ensure that the crops grow

00:01:15.573 --> 00:01:18.437
as much as they can, we add fertilizer

00:01:18.437 --> 00:01:20.408
to it, and a lot of
that fertilizer might be

00:01:20.408 --> 00:01:22.643
nitrogen, it might be
phosphorous in the form

00:01:22.643 --> 00:01:25.643
of phosphates, so we add fertilizer.

00:01:31.371 --> 00:01:35.577
And the biggest culprit
here tends to be phosphates,

00:01:35.577 --> 00:01:37.493
the phosphorous in them,
and that helps the plants

00:01:37.493 --> 00:01:38.956
grow more.

00:01:38.956 --> 00:01:41.509
That helps the plants grow more,

00:01:41.509 --> 00:01:42.969
which seems like a good thing,

00:01:42.969 --> 00:01:44.830
but there's another side effect

00:01:44.830 --> 00:01:46.618
that happens because of this.

00:01:46.618 --> 00:01:50.896
As the water, either due
to rain or irrigation

00:01:50.896 --> 00:01:55.182
for the crops, as the water
flows from those crops

00:01:55.182 --> 00:01:57.426
into local streams and
rivers, it'll eventually

00:01:57.426 --> 00:02:00.973
find its way into local
streams and rivers.

00:02:00.973 --> 00:02:05.289
those streams and rivers
and lakes are going to have

00:02:05.289 --> 00:02:08.428
an excess of those
fertilizers, in particular

00:02:08.428 --> 00:02:10.264
maybe those phosphates.

00:02:10.264 --> 00:02:13.173
So you have more phosphates in this,

00:02:13.173 --> 00:02:15.103
let's say this is a lake of some kind,

00:02:15.103 --> 00:02:16.403
so I'll make it big.

00:02:16.403 --> 00:02:18.757
Let's say this is a lake
of it and we already know

00:02:18.757 --> 00:02:21.217
that things like phosphates
are the rate-limiting

00:02:21.217 --> 00:02:22.800
factors for plants.

00:02:23.898 --> 00:02:26.663
And so, you could have
photosynthetic organisms

00:02:26.663 --> 00:02:30.320
like algae in this lake
and if it didn't have

00:02:30.320 --> 00:02:31.734
the fertilizer you
might just have a little

00:02:31.734 --> 00:02:33.258
bit of the algae.

00:02:33.258 --> 00:02:35.989
But now since they're getting
all of these phosphates,

00:02:35.989 --> 00:02:38.081
the algae can go crazy.

00:02:38.081 --> 00:02:40.531
The algae can go crazy and grow all over

00:02:40.531 --> 00:02:43.019
the surface of the lake.

00:02:43.019 --> 00:02:45.031
And so this is where that algae is getting

00:02:45.031 --> 00:02:46.098
over-nourished.

00:02:46.098 --> 00:02:47.875
It's getting way more
phosphates than would have

00:02:47.875 --> 00:02:51.306
typically happened just if
there wasn't fertilizer,

00:02:51.306 --> 00:02:53.027
if there wasn't this runoff happening.

00:02:53.027 --> 00:02:55.370
And it's not just fertilizers,
even some detergents

00:02:55.370 --> 00:02:59.090
in the past, they have,
you have sodium phosphates,

00:02:59.090 --> 00:03:03.189
which once again, can
cause this eutrophication.

00:03:03.189 --> 00:03:05.400
And you might say okay,
well why is this bad?

00:03:05.400 --> 00:03:07.014
It could just make the
surface of the water

00:03:07.014 --> 00:03:09.118
a little bit less clear,
a little bit green,

00:03:09.118 --> 00:03:11.657
but hey, there's living things here.

00:03:11.657 --> 00:03:14.755
Well the issue is what
happens once this algae dies.

00:03:14.755 --> 00:03:17.518
Once this algae dies, and it starts

00:03:17.518 --> 00:03:21.268
to float down, that can
be food for bacteria.

00:03:23.177 --> 00:03:25.865
That could be food for bacteria, and

00:03:25.865 --> 00:03:29.200
as the bacteria consume it, they also use

00:03:29.200 --> 00:03:30.135
oxygen.

00:03:30.135 --> 00:03:32.553
We've already talked
about the role of oxygen

00:03:32.553 --> 00:03:34.219
in respiration.

00:03:34.219 --> 00:03:37.584
The bacteria will
consume all of the oxygen

00:03:37.584 --> 00:03:38.973
in the water.

00:03:38.973 --> 00:03:41.931
Now a lot of times when
we think of ocean animals,

00:03:41.931 --> 00:03:42.764
so when we think of,

00:03:42.764 --> 00:03:45.515
I'll just draw a little fish here,

00:03:45.515 --> 00:03:47.848
and so that's a little fish,

00:03:48.726 --> 00:03:50.900
we don't often think
about the necessity of

00:03:50.900 --> 00:03:51.895
oxygen in the water.

00:03:51.895 --> 00:03:54.900
But ocean animals need
oxygen just like we do,

00:03:54.900 --> 00:03:56.620
and they get that oxygen,

00:03:56.620 --> 00:03:59.981
waves can crash and as the
waves crash it brings in

00:03:59.981 --> 00:04:01.898
oxygen from the surface

00:04:03.009 --> 00:04:06.373
that ocean animals can
use in order to live,

00:04:06.373 --> 00:04:09.123
in order to do their respiration.

00:04:10.030 --> 00:04:12.334
But now all of a sudden,
if this bacteria, because

00:04:12.334 --> 00:04:15.524
they're able to decompose all this algae

00:04:15.524 --> 00:04:17.811
that is dying, if they're
consuming all of the

00:04:17.811 --> 00:04:22.006
oxygen, well it depletes
the oxygen from the water

00:04:22.006 --> 00:04:24.870
so that the ocean animals
can't live there anymore.

00:04:24.870 --> 00:04:28.121
And so the irony here is,
by having this fertilizer

00:04:28.121 --> 00:04:30.937
runoff, by having these extra phosphates,

00:04:30.937 --> 00:04:34.033
this eutrophication, by
allowing one thing to grow

00:04:34.033 --> 00:04:36.605
far more than it would have otherwise,

00:04:36.605 --> 00:04:39.246
it actually ends up depleting the oxygen

00:04:39.246 --> 00:04:41.989
that keeps other things from growing.

00:04:41.989 --> 00:04:45.217
And it actually creates
what we call dead zones.

00:04:45.217 --> 00:04:48.316
So this fish is going
to die and other animals

00:04:48.316 --> 00:04:49.754
like it aren't going to
live because there's not

00:04:49.754 --> 00:04:52.030
gonna be enough oxygen in that water.

00:04:52.030 --> 00:04:55.104
And then we have a Dead Zone.

00:04:55.104 --> 00:04:56.479
And this is a serious problem.

00:04:56.479 --> 00:04:57.585
We have some pictures here.

00:04:57.585 --> 00:05:01.668
This is potential
eutrophication in this picture.

00:05:02.603 --> 00:05:04.859
Let me show you some more.

00:05:04.859 --> 00:05:06.951
This is another one, and
you've probably seen this,

00:05:06.951 --> 00:05:09.929
especially in places that
might have sewage runoff.

00:05:09.929 --> 00:05:13.240
It's really happening because
there's extra nutrients

00:05:13.240 --> 00:05:17.618
that are allowing these
algal blooms or aldral algo,

00:05:17.618 --> 00:05:21.519
I don't know, to go out
of control and when they

00:05:21.519 --> 00:05:24.700
decompose the bacteria is
sopping up all the oxygen,

00:05:24.700 --> 00:05:26.537
nothing else can live.

00:05:26.537 --> 00:05:29.036
And this is happening on a macro scale.

00:05:29.036 --> 00:05:33.555
So right over here is
kind of a global picture

00:05:33.555 --> 00:05:37.297
of dead zones that we
have and you see them

00:05:37.297 --> 00:05:38.565
all through the world.

00:05:38.565 --> 00:05:40.352
And you see they are
typically concentrated

00:05:40.352 --> 00:05:43.452
where we have more industrialized nations,

00:05:43.452 --> 00:05:47.435
where we have either more
agriculture happening,

00:05:47.435 --> 00:05:50.483
more industrial agriculture, where they

00:05:50.483 --> 00:05:53.031
might be using more
fertilizer and also where

00:05:53.031 --> 00:05:54.779
you might have more runoff
from cities that will

00:05:54.779 --> 00:05:58.183
have nutrients like the
phosphates, that will cause

00:05:58.183 --> 00:06:00.569
this eutrophication to happen.

00:06:00.569 --> 00:06:02.477
And if you were to zoom
in, let's say on the

00:06:02.477 --> 00:06:05.193
Caspian Sea, you can
see this in more detail,

00:06:05.193 --> 00:06:07.447
you can visually see this.

00:06:07.447 --> 00:06:10.423
So, right over here is a satellite image

00:06:10.423 --> 00:06:13.654
of the Caspian Sea and you
can see the eutrophication.

00:06:13.654 --> 00:06:17.821
You can see the algeal, algal
blooms throughout this area.

00:06:18.846 --> 00:06:21.516
It's making the water less clear.

00:06:21.516 --> 00:06:23.975
So this is a serious
ecological thing that we

00:06:23.975 --> 00:06:25.092
have to think about.

00:06:25.092 --> 00:06:28.152
On one level, phosphates
and fertilizers, nitrates

00:06:28.152 --> 00:06:29.980
seem like a good thing,
it's helping us grow

00:06:29.980 --> 00:06:31.960
more crops, but we have to be very careful

00:06:31.960 --> 00:06:34.543
with where it actually ends up.


Phosphorous cycle

WEBVTT
Kind: captions
Language: en

00:00:00.218 --> 00:00:01.936
- [Instructor] Let's
talk a little bit about

00:00:01.936 --> 00:00:06.114
the element, phosphorous,
and its importance to life

00:00:06.114 --> 00:00:08.707
and how it cycles through living systems.

00:00:08.707 --> 00:00:11.952
So we're gonna talk about
the phosphorous cycle.

00:00:11.952 --> 00:00:14.800
First, it's important to
appreciate that phosphorous

00:00:14.800 --> 00:00:18.031
is a very reactive element,
so it's seldom found

00:00:18.031 --> 00:00:19.350
by itself.

00:00:19.350 --> 00:00:22.183
Normally, we find it in phosphate form.

00:00:22.183 --> 00:00:26.518
So this right over here, the
orange is a phosphorous atom,

00:00:26.518 --> 00:00:30.044
and it's bound to four
oxygens right over here,

00:00:30.044 --> 00:00:32.377
and at least the way that
it's set up right over here,

00:00:32.377 --> 00:00:34.763
it would have a -3 charge.

00:00:34.763 --> 00:00:38.372
This would often form ionic
bonds with other things,

00:00:38.372 --> 00:00:40.585
or one of the oxygens
can have a covalent bond,

00:00:40.585 --> 00:00:42.937
or you can form phosphoric
acid where the oxygen's

00:00:42.937 --> 00:00:45.142
bound to hydrogens, but
this is the general form

00:00:45.142 --> 00:00:46.879
that you typically find it.

00:00:46.879 --> 00:00:48.628
That's the phosphorous
that I'm pointing to,

00:00:48.628 --> 00:00:52.935
but this whole thing, we
would call this a phosphate.

00:00:52.935 --> 00:00:55.065
We would call this a phosphate.

00:00:55.065 --> 00:00:59.144
You see this showing up in
very important macromolecules

00:00:59.144 --> 00:01:00.377
in biology.

00:01:00.377 --> 00:01:04.544
This is DNA, and both DNA and
RNA have phosphate backbones.

00:01:07.214 --> 00:01:10.221
You can see the sides of the
ladder, I guess you could

00:01:10.221 --> 00:01:13.556
view it as that word, the
backbone of our DNA molecules.

00:01:13.556 --> 00:01:16.108
You can see these phosphates
there and in the center

00:01:16.108 --> 00:01:20.773
of the phosphate, you
have the phosphorous atom.

00:01:20.773 --> 00:01:23.065
Also over here, you have ATP.

00:01:23.065 --> 00:01:24.893
In biology, we study that.

00:01:24.893 --> 00:01:26.056
It's the powerhouse.

00:01:26.056 --> 00:01:28.783
It's the energy currency
of biological systems,

00:01:28.783 --> 00:01:31.761
stands for adenosine triphosphate.

00:01:31.761 --> 00:01:34.313
You have three phosphate
groups right over here,

00:01:34.313 --> 00:01:37.100
and when you pluck one of
those phosphate groups off,

00:01:37.100 --> 00:01:39.262
it can power reactions.

00:01:39.262 --> 00:01:41.107
It can change the confirmation of enzymes.

00:01:41.107 --> 00:01:43.429
It can do all sorts of interesting things,

00:01:43.429 --> 00:01:45.747
so hopefully you can
appreciate that phosphate

00:01:45.747 --> 00:01:49.136
is essential for life,
'cause life as we know it

00:01:49.136 --> 00:01:51.719
involves ATP, and involves DNA,

00:01:53.142 --> 00:01:55.036
and many, many other
things that phosphates

00:01:55.036 --> 00:01:56.595
are involved with.

00:01:56.595 --> 00:01:59.454
Phosphate, or phosphorous
I should say in particular,

00:01:59.454 --> 00:02:02.544
is a little bit different
than carbon or nitrogen

00:02:02.544 --> 00:02:05.167
in that it's not found in the atmosphere.

00:02:05.167 --> 00:02:08.304
It's not typically found as a gas.

00:02:08.304 --> 00:02:12.387
Instead, phosphate is
going to be found in rocks,

00:02:13.983 --> 00:02:16.698
and it's going to be
phosphate-based rocks.

00:02:16.698 --> 00:02:18.754
There will be other elements in there.

00:02:18.754 --> 00:02:20.429
It could be chlorine.

00:02:20.429 --> 00:02:23.347
There's a bunch of different
types of phosphate rocks,

00:02:23.347 --> 00:02:26.140
but when they're in
their sedimentary form,

00:02:26.140 --> 00:02:28.557
let me create some soil here.

00:02:29.521 --> 00:02:33.702
Let's say this soil has
some phosphates in it.

00:02:33.702 --> 00:02:38.683
Then, it allows things like
plants to grow in that soil.

00:02:38.683 --> 00:02:41.037
This is a plant growing in that soil,

00:02:41.037 --> 00:02:44.810
and the plant, we've
talked about it before,

00:02:44.810 --> 00:02:49.036
it could be fixing carbon
from the atmosphere

00:02:49.036 --> 00:02:53.745
using light energy, but its
phosphate is going to come

00:02:53.745 --> 00:02:55.203
from the soil.

00:02:55.203 --> 00:02:57.640
That phosphate was already
there, and that helps

00:02:57.640 --> 00:02:59.686
that plant grow because that
plant needs that phosphate

00:02:59.686 --> 00:03:03.853
for its ATP, its DNA, its
RNA, and for other things.

00:03:05.078 --> 00:03:08.927
Phosphate is often considered
a rate limiting factor

00:03:08.927 --> 00:03:11.005
for the growth of things like plants,

00:03:11.005 --> 00:03:12.651
and that's why a lot of fertilizers

00:03:12.651 --> 00:03:15.994
will have phosphorous
in them, or phosphates,

00:03:15.994 --> 00:03:18.218
or nitrogen's another one.

00:03:18.218 --> 00:03:20.507
Next time you think about
fertilizer, you're fertilizing

00:03:20.507 --> 00:03:22.218
things in your garden,
look at the ingredients.

00:03:22.218 --> 00:03:25.206
You will see phosphate
there because that might be

00:03:25.206 --> 00:03:28.083
the scarce resource or
the thing that is limiting

00:03:28.083 --> 00:03:30.103
the actual growth of the plant.

00:03:30.103 --> 00:03:30.936
Then you might say,

00:03:30.936 --> 00:03:33.280
"I have ATP and DNA in my body.

00:03:33.280 --> 00:03:34.895
"How do I get phosphates?"

00:03:34.895 --> 00:03:38.346
Well, you get it by eating plants.

00:03:38.346 --> 00:03:40.596
This is you eating a plant.

00:03:42.074 --> 00:03:44.268
The plant goes back there.

00:03:44.268 --> 00:03:46.768
How does this form a cycle?

00:03:46.768 --> 00:03:49.877
When any of this living matter dies,

00:03:49.877 --> 00:03:51.014
and I've said it in previous video,

00:03:51.014 --> 00:03:52.955
I'll show the dead plant
'cause a dead animal,

00:03:52.955 --> 00:03:54.940
it's just a little darker.

00:03:54.940 --> 00:03:58.009
So whenever you see the
plant now, it's dead.

00:03:58.009 --> 00:03:59.988
Let's say it got buried
somehow, some soil,

00:03:59.988 --> 00:04:02.824
so it's all just a dead
plant right over there.

00:04:02.824 --> 00:04:06.991
The phosphates in that plant
can then go back into the soil.

00:04:08.757 --> 00:04:12.010
You could view this as a very tight cycle

00:04:12.010 --> 00:04:15.125
and the same thing would
be once you die or I die,

00:04:15.125 --> 00:04:18.038
the phosphates, if we're
buried, would go into the soil,

00:04:18.038 --> 00:04:21.918
but there could be other
ways that the phosphate

00:04:21.918 --> 00:04:25.020
and the corresponding
phosphorous gets recycled.

00:04:25.020 --> 00:04:29.178
You could think on a bigger
scale where you could have,

00:04:29.178 --> 00:04:31.345
let's say there's a river.

00:04:32.368 --> 00:04:34.176
There's a river right over here.

00:04:34.176 --> 00:04:35.579
This is either a very small river

00:04:35.579 --> 00:04:38.236
or a very big plant that I drew.

00:04:38.236 --> 00:04:41.260
That river can take
phosphates from that soil,

00:04:41.260 --> 00:04:43.153
and it could put it into the ocean,

00:04:43.153 --> 00:04:46.809
and then those phosphates
could be used by sea life.

00:04:46.809 --> 00:04:49.399
Then when that sea life
dies, it goes to the base

00:04:49.399 --> 00:04:51.953
of the ocean floor, and at
some point in the future,

00:04:51.953 --> 00:04:53.999
that base of the ocean
floor could be pushed up,

00:04:53.999 --> 00:04:55.062
and a plant grows on it.

00:04:55.062 --> 00:04:58.732
So you can imagine all
sorts of these cycles.

00:04:58.732 --> 00:05:00.729
We're actually seeing
more and more of this

00:05:00.729 --> 00:05:02.304
as human beings have said,

00:05:02.304 --> 00:05:05.809
"If phosphate is the rate
limiting factor for the growth

00:05:05.809 --> 00:05:07.718
"of plants, and we need
to grow a lot of plants

00:05:07.718 --> 00:05:11.728
"in order to feed ourselves,
we've started mining it."

00:05:11.728 --> 00:05:14.103
We've started adding a
lot more to the soil,

00:05:14.103 --> 00:05:18.446
but it also allows a lot
of that to be washed away

00:05:18.446 --> 00:05:21.329
into our rivers and streams,
and eventually end up

00:05:21.329 --> 00:05:22.275
in the ocean.

00:05:22.275 --> 00:05:25.667
As we'll see, this can
actually have very negative

00:05:25.667 --> 00:05:28.250
consequences for our biosphere.


Nitrogen cycle

WEBVTT
Kind: captions
Language: en

00:00:00.357 --> 00:00:02.417
- [Voiceover] Nitrogen
often gets less attention

00:00:02.417 --> 00:00:06.174
than carbon or oxygen, but nitrogen is

00:00:06.174 --> 00:00:08.851
very important to life as well.

00:00:08.851 --> 00:00:13.018
And like carbon and oxygen, it
cycles through our biosphere.

00:00:14.584 --> 00:00:17.743
Now, one thing that's maybe
surprising about nitrogen,

00:00:17.743 --> 00:00:19.142
if you haven't studied it much,

00:00:19.142 --> 00:00:22.587
is that it is very, very
common in our atmosphere.

00:00:22.587 --> 00:00:26.670
78% of our atmosphere
is molecular nitrogen,

00:00:28.192 --> 00:00:29.874
so it's in the form of N2.

00:00:29.874 --> 00:00:31.766
So this right over here
is molecular nitrogen.

00:00:31.766 --> 00:00:35.933
You have two nitrogen atoms
covalently bonded to each other.

00:00:37.726 --> 00:00:41.809
Now, unlike carbon, which can
be directly fixed by plants,

00:00:41.809 --> 00:00:43.537
in the carbon cycle video we talk about

00:00:43.537 --> 00:00:46.695
how autotrophs like plants
can take light energy

00:00:46.695 --> 00:00:49.288
and use that to fix carbon from the air

00:00:49.288 --> 00:00:51.814
into a solid form and store that energy

00:00:51.814 --> 00:00:54.158
in those carbon-carbon bonds,

00:00:54.158 --> 00:00:56.934
nitrogen cannot be directly fixed

00:00:56.934 --> 00:00:59.944
by complex organisms, like plants.

00:00:59.944 --> 00:01:04.235
Instead, the key actor that
fixes the nitrogen from the air,

00:01:04.235 --> 00:01:08.462
so you have all of these N2
molecules in the air here,

00:01:08.462 --> 00:01:10.995
the actors here aren't plants,

00:01:10.995 --> 00:01:14.094
but prokaryotes, like bacteria.

00:01:14.094 --> 00:01:15.921
So let me draw some soil here.

00:01:15.921 --> 00:01:18.447
And the bacteria could be in
a bunch of different places.

00:01:18.447 --> 00:01:22.030
But you could have a
bacteria in this soil.

00:01:23.056 --> 00:01:25.711
I'll draw them a little bit
bigger so you can see it.

00:01:25.711 --> 00:01:29.601
Some prokaryotes right over
here, there's the bacteria.

00:01:29.601 --> 00:01:32.660
And certain types of bacteria are capable,

00:01:32.660 --> 00:01:36.511
and prokaryotes are
capable of fixing nitrogen.

00:01:36.511 --> 00:01:38.443
So what they're able
to do, is they're able

00:01:38.443 --> 00:01:41.135
to take that N2 and turn it into a form

00:01:41.135 --> 00:01:45.412
that is more usable by
complex organisms like plants.

00:01:45.412 --> 00:01:49.256
So this is the bacteria, right over here.

00:01:49.256 --> 00:01:50.656
So that's the bacteria.

00:01:50.656 --> 00:01:52.298
That's this little circular strand of DNA,

00:01:52.298 --> 00:01:53.131
I could draw other--

00:01:53.131 --> 00:01:55.488
I could make it more complicated,

00:01:55.488 --> 00:01:56.901
but let me just do it like this.

00:01:56.901 --> 00:01:59.484
Bacteria is able to fix that N2

00:02:00.683 --> 00:02:03.016
and take it to ammonia, NH3.

00:02:04.929 --> 00:02:08.800
And it's this ammonia, it's this ammonia,

00:02:08.800 --> 00:02:11.453
that is really useful for plants

00:02:11.453 --> 00:02:13.414
and other complex organisms.

00:02:13.414 --> 00:02:15.249
So this right over here.

00:02:15.249 --> 00:02:18.563
So as the plant in the
video on the carbon cycle

00:02:18.563 --> 00:02:20.729
we talk about how plants fix carbon,

00:02:20.729 --> 00:02:25.476
carbon makes up a large
part of organic molecules,

00:02:25.476 --> 00:02:27.877
but many important organic molecules

00:02:27.877 --> 00:02:29.604
also need nitrogen.

00:02:29.604 --> 00:02:32.406
And these are examples
of organic molecules

00:02:32.406 --> 00:02:33.713
that you will find in plants,

00:02:33.713 --> 00:02:36.145
and you'll find them in many
different types of organisms.

00:02:36.145 --> 00:02:39.562
So this right over here is an amino acid,

00:02:41.010 --> 00:02:42.718
amino acid,

00:02:42.718 --> 00:02:45.607
we see the nitrogen right over there.

00:02:45.607 --> 00:02:48.768
This right over here is
our good old friend, ATP,

00:02:48.768 --> 00:02:53.176
adenosine triphosphate,
the quick-store of energy

00:02:53.176 --> 00:02:55.041
in biological systems.

00:02:55.041 --> 00:02:58.042
You see the nitrogen in
blue right over here.

00:02:58.042 --> 00:02:59.959
This is the famous DNA,

00:03:02.367 --> 00:03:04.089
deoxyribonucleic acid.

00:03:04.089 --> 00:03:08.482
And you see the nitrogens
throughout this macro molecule.

00:03:08.482 --> 00:03:10.848
So nitrogen is essential for life,

00:03:10.848 --> 00:03:13.983
but the step of fixing that nitrogen

00:03:13.983 --> 00:03:17.254
that's done by bacteria, which
can then produce the ammonia,

00:03:17.254 --> 00:03:19.531
which is then usable by plants,

00:03:19.531 --> 00:03:22.828
and then by eating the
plants, beings like you and me

00:03:22.828 --> 00:03:26.269
can get that nitrogen into our systems.

00:03:26.269 --> 00:03:28.757
Now, it's not just a one-way street.

00:03:28.757 --> 00:03:31.203
That is, we're just
going from the nitrogen

00:03:31.203 --> 00:03:33.557
in the atmosphere, and it
gets fixed by prokaryotes,

00:03:33.557 --> 00:03:35.599
and then that gets used--

00:03:35.599 --> 00:03:37.893
that gets turned into ammonia

00:03:37.893 --> 00:03:39.756
and gets used by higher organisms.

00:03:39.756 --> 00:03:42.660
Because eventually all of
it would, would get deleted.

00:03:42.660 --> 00:03:46.077
As an organism dies, as an organism dies,

00:03:47.177 --> 00:03:48.321
let's say this is a dead organism,

00:03:48.321 --> 00:03:49.400
it could be a bacteria, but I'll go

00:03:49.400 --> 00:03:51.379
with a higher organism,
a multi-cellular one,

00:03:51.379 --> 00:03:52.824
this is a dead plant here,

00:03:52.824 --> 00:03:56.186
I don't want to draw dead
animals, it's more morbid.

00:03:56.186 --> 00:03:58.363
So let's say this is a dead plant there.

00:03:58.363 --> 00:04:00.231
And when it gets decomposed,

00:04:00.231 --> 00:04:03.015
and there are many
different types of bacteria,

00:04:03.015 --> 00:04:04.888
even though I might draw them
kind of looking the same,

00:04:04.888 --> 00:04:07.865
let's say this is another
bacteria in orange.

00:04:07.865 --> 00:04:10.264
As these bacteria digest these plants,

00:04:10.264 --> 00:04:13.458
they're able to, they could
take some of the nitrogen

00:04:13.458 --> 00:04:16.121
and break them down into
nitrites and nitrates,

00:04:16.121 --> 00:04:19.117
these are molecules
involving a nitrogen bonded

00:04:19.117 --> 00:04:21.117
to two or three oxygens,

00:04:21.954 --> 00:04:24.516
and they can take them back to ammonia.

00:04:24.516 --> 00:04:28.906
So we can go back, so
we can have a bacteria

00:04:28.906 --> 00:04:30.419
that take us back to ammonia,

00:04:30.419 --> 00:04:32.242
or eventually by converting the nitrogen

00:04:32.242 --> 00:04:35.285
into nitrites and
nitrates, we could go back

00:04:35.285 --> 00:04:39.452
we could go back to that
molecular nitrogen, that N2.

00:04:41.491 --> 00:04:45.353
That then gets released
back into the atmosphere.

00:04:45.353 --> 00:04:48.190
So, or it could get, even, you know,

00:04:48.190 --> 00:04:50.248
it could get stored in other ways as well.

00:04:50.248 --> 00:04:52.820
But, in general, as you
see here, this pattern.

00:04:52.820 --> 00:04:56.205
That we have these elements
that are essential for life.

00:04:56.205 --> 00:04:59.410
They don't just disappear
or form out of nowhere,

00:04:59.410 --> 00:05:03.535
they're constantly being
recycled in our biosphere.

00:05:03.535 --> 00:05:05.436
And nitrogen doesn't get as much attention

00:05:05.436 --> 00:05:09.975
as carbon or oxygen, but
it is essential for life.

00:05:09.975 --> 00:05:12.058
In fact, when you look at

00:05:13.839 --> 00:05:15.120
especially plants and growing plants,

00:05:15.120 --> 00:05:16.101
and you think about fertilizer.

00:05:16.101 --> 00:05:17.566
Fertilizer is something
that you should think

00:05:17.566 --> 00:05:20.093
if you add it to a plant,
it's going to grow more.

00:05:20.093 --> 00:05:23.197
So without it, it kind of limits
how fast a plant can grow,

00:05:23.197 --> 00:05:25.508
a lot of fertilizer is
going to have nitrogen,

00:05:25.508 --> 00:05:27.679
and in other video, we're going
to talk about phosphorous.

00:05:27.679 --> 00:05:29.548
And that phosphorous and nitrogen

00:05:29.548 --> 00:05:32.010
and their availability in the soil,

00:05:32.010 --> 00:05:34.754
is often a rate-limiting
factor for plants.

00:05:34.754 --> 00:05:37.271
And you know that, because
if you add more nitrogen

00:05:37.271 --> 00:05:39.056
or that phosphorous, it will
add more ammonia to that soil,

00:05:39.056 --> 00:05:43.223
you're going to, the plants
are going to grow faster.


Carbon cycle

WEBVTT
Kind: captions
Language: en

00:00:00.350 --> 00:00:03.364
- [Instructor] I wanna talk
a little bit about carbon

00:00:03.364 --> 00:00:06.874
and how it cycles through our biosphere.

00:00:06.874 --> 00:00:08.918
And we touch on this in other videos.

00:00:08.918 --> 00:00:11.589
But when we talk about
elements like carbon,

00:00:11.589 --> 00:00:13.262
they don't just appear and disappear

00:00:13.262 --> 00:00:14.814
all of a sudden in our biosphere.

00:00:14.814 --> 00:00:18.265
For the most part, they have
been here since the beginning.

00:00:18.265 --> 00:00:22.045
But they just get recycled
from one form to another.

00:00:22.045 --> 00:00:24.870
And that is also true of carbon.

00:00:24.870 --> 00:00:26.904
And to appreciate carbon's importance

00:00:26.904 --> 00:00:29.216
in our biosphere, and especially to life,

00:00:29.216 --> 00:00:31.317
I have some, some important molecules,

00:00:31.317 --> 00:00:33.833
or examples of important
molecules that involve carbon.

00:00:33.833 --> 00:00:38.405
In all of these, the carbons
are these dark gray colors.

00:00:38.405 --> 00:00:40.249
So this right over here,

00:00:40.249 --> 00:00:41.416
this molecule,

00:00:42.557 --> 00:00:43.890
this is glucose.

00:00:44.840 --> 00:00:46.322
Glucose, simple sugar.

00:00:46.322 --> 00:00:50.374
It's where we can derive
a lot of our energy from.

00:00:50.374 --> 00:00:52.428
This is ATP, you can view it as

00:00:52.428 --> 00:00:56.595
a more immediate store of
energy in biological systems.

00:00:57.490 --> 00:00:59.906
This right over here is

00:00:59.906 --> 00:01:01.906
one of many amino acids.

00:01:02.942 --> 00:01:06.128
The amino acids make up our proteins.

00:01:06.128 --> 00:01:08.953
This right over here is DNA.

00:01:08.953 --> 00:01:10.018
And in all of these you can see

00:01:10.018 --> 00:01:11.081
the role that carbon is playing.

00:01:11.081 --> 00:01:12.842
In fact, sometimes the
carbon's hard to see

00:01:12.842 --> 00:01:14.359
because it's closer to the
center of these molecules

00:01:14.359 --> 00:01:16.619
because the carbon, for the most part,

00:01:16.619 --> 00:01:17.952
forms the backbone.

00:01:17.952 --> 00:01:20.768
Because carbon's this really
neat, this really neat element,

00:01:20.768 --> 00:01:22.143
this really neat atom

00:01:22.143 --> 00:01:24.109
that can make four bonds.

00:01:24.109 --> 00:01:27.645
It can make these really
really really cool structures.

00:01:27.645 --> 00:01:30.648
But the question is how does carbon cycle

00:01:30.648 --> 00:01:32.250
through our biosphere?

00:01:32.250 --> 00:01:33.926
And we can get as simple or as complex

00:01:33.926 --> 00:01:35.904
as we want to when we discuss this.

00:01:35.904 --> 00:01:37.586
But on very very simple terms,

00:01:37.586 --> 00:01:40.618
this is how my brain tends to
think about the carbon cycle.

00:01:40.618 --> 00:01:43.392
You can imagine the
carbon in our atmosphere

00:01:43.392 --> 00:01:47.378
that's mainly in the form
of molecular carbon dioxide.

00:01:47.378 --> 00:01:48.773
So this right over here,

00:01:48.773 --> 00:01:50.023
this is CO two.

00:01:51.102 --> 00:01:53.198
Once again, the carbon
is in the middle there,

00:01:53.198 --> 00:01:55.746
bonded to the two oxygens.

00:01:55.746 --> 00:01:57.623
And as much as we talk about CO two,

00:01:57.623 --> 00:02:00.964
and as important as carbon
is to living systems.

00:02:00.964 --> 00:02:03.286
In fact, our bodies are 18

00:02:03.286 --> 00:02:04.953
to 19 percent carbon

00:02:08.279 --> 00:02:09.526
carbon by mass.

00:02:09.526 --> 00:02:13.157
So it's very important
for biological systems.

00:02:13.157 --> 00:02:15.215
As important as carbon
is to biological systems,

00:02:15.215 --> 00:02:17.240
and the role carbon dioxide plays

00:02:17.240 --> 00:02:19.489
in things like global
warming, it actually makes up

00:02:19.489 --> 00:02:21.866
a very small percentage of our atmosphere.

00:02:21.866 --> 00:02:24.199
It's only about 0.04 percent

00:02:25.610 --> 00:02:27.507
of the gas in our atmosphere.

00:02:27.507 --> 00:02:29.116
Most of our atmosphere
is actually nitrogen,

00:02:29.116 --> 00:02:31.364
78 percent, you don't talk a lot about it.

00:02:31.364 --> 00:02:33.574
And oxygen, 21 percent.

00:02:33.574 --> 00:02:35.044
And then a bunch of other,

00:02:35.044 --> 00:02:37.681
a bunch of other elements and molecules.

00:02:37.681 --> 00:02:40.028
But the very simple
version of the carbon cycle

00:02:40.028 --> 00:02:44.734
is, okay, you have this
atmospheric carbon dioxide,

00:02:44.734 --> 00:02:47.398
molecular carbon dioxide,
hanging out in the air.

00:02:47.398 --> 00:02:50.856
And you have autotrophs like plants.

00:02:50.856 --> 00:02:52.990
So let's say this is the ground,

00:02:52.990 --> 00:02:55.417
and I have a growing plant.

00:02:55.417 --> 00:02:57.604
So that's a plant right over there.

00:02:57.604 --> 00:03:01.058
That's its leaf, that's another leaf.

00:03:01.058 --> 00:03:03.785
And the way that plants grow

00:03:03.785 --> 00:03:05.981
is they're able to take light energy.

00:03:05.981 --> 00:03:09.589
So that's energy coming in from the sun,

00:03:09.589 --> 00:03:12.468
and use that energy to fix carbon.

00:03:12.468 --> 00:03:14.590
Now fixing carbon sounds
like a very fancy thing,

00:03:14.590 --> 00:03:18.479
but it's literally taking
that molecular carbon dioxide

00:03:18.479 --> 00:03:20.838
out of the air and
fixing the carbon from it

00:03:20.838 --> 00:03:24.589
to form these different
molecules in the plant,

00:03:24.589 --> 00:03:26.768
that help the plant, that
give the plant structure,

00:03:26.768 --> 00:03:28.571
that give the plant energy.

00:03:28.571 --> 00:03:30.435
And so that mass of that plant,

00:03:30.435 --> 00:03:32.332
I'm actually in this room
I'm in, there's a houseplant

00:03:32.332 --> 00:03:35.256
right next to me, it's
not just growing out of,

00:03:35.256 --> 00:03:37.875
I mean, I guess you could say
it's growing out of thin air,

00:03:37.875 --> 00:03:39.791
but the mass isn't just
magically appearing.

00:03:39.791 --> 00:03:43.311
It's taking that mass out of the air.

00:03:43.311 --> 00:03:44.634
And so that's where,

00:03:44.634 --> 00:03:49.067
so that's what allows this
plant to keep growing.

00:03:49.067 --> 00:03:51.138
And so, once again, as I said,

00:03:51.138 --> 00:03:52.667
some of that will be in
the form of proteins,

00:03:52.667 --> 00:03:55.684
amino acids, it could form
structural components.

00:03:55.684 --> 00:03:57.395
It could be fats,

00:03:57.395 --> 00:03:59.209
and also some of it is energy.

00:03:59.209 --> 00:04:01.073
And you could imagine other animals

00:04:01.073 --> 00:04:03.799
that can't do this, that
can't photosynthesize,

00:04:03.799 --> 00:04:05.276
well, they might wanna eat these plants

00:04:05.276 --> 00:04:06.224
for that energy.

00:04:06.224 --> 00:04:08.846
In other videos, we talk
about the food cycle.

00:04:08.846 --> 00:04:11.536
And so, this could be me.

00:04:11.536 --> 00:04:14.145
This could be me having a salad,

00:04:14.145 --> 00:04:17.870
and I might want to eat that plant.

00:04:17.870 --> 00:04:20.867
I might wanna eat the
plant for the sugar in it.

00:04:20.867 --> 00:04:22.559
Maybe it's an apple of some kind,

00:04:22.559 --> 00:04:27.390
and then that gives my body
the energy to live and grow.

00:04:27.390 --> 00:04:30.701
And as I, as I metabolize that glucose,

00:04:30.701 --> 00:04:33.124
so for example glucose
is one of the molecules

00:04:33.124 --> 00:04:35.345
that that plant can form

00:04:35.345 --> 00:04:38.433
by taking that carbon out of the air.

00:04:38.433 --> 00:04:42.058
And then I might metabolize that glucose

00:04:42.058 --> 00:04:43.771
from that plant I just ate,

00:04:43.771 --> 00:04:47.989
and as I do that, I will
release carbon dioxide.

00:04:47.989 --> 00:04:50.322
So I will release the CO two

00:04:51.181 --> 00:04:52.541
back in the air.

00:04:52.541 --> 00:04:54.908
And then you can see that
you can form a cycle here.

00:04:54.908 --> 00:04:58.352
The CO two gets released by
things that are metabolizing

00:04:58.352 --> 00:05:02.151
these organic molecules, and
then it can get fixed again

00:05:02.151 --> 00:05:04.724
by autotrophs, which are
able to store the energy

00:05:04.724 --> 00:05:08.072
from the sun with, in
terms of these bonds,

00:05:08.072 --> 00:05:10.186
by fixing this carbon.

00:05:10.186 --> 00:05:12.526
But there's other
pathways that we can have

00:05:12.526 --> 00:05:14.245
to have these cycles.

00:05:14.245 --> 00:05:17.286
For example, some of the CO
two, it could be absorbed

00:05:17.286 --> 00:05:18.700
into the ocean.

00:05:18.700 --> 00:05:20.867
It could be absorbed into,

00:05:21.983 --> 00:05:23.935
into the ocean.

00:05:23.935 --> 00:05:26.474
And in the ocean it can form carbonate,

00:05:26.474 --> 00:05:29.094
and so once again you still see
the carbon right over there,

00:05:29.094 --> 00:05:31.169
carbon bonded to three oxygens,

00:05:31.169 --> 00:05:35.111
and calcium carbonate is a key constituent

00:05:35.111 --> 00:05:37.194
in things like seashells.

00:05:39.917 --> 00:05:42.493
And over time, as the
sea shells break down,

00:05:42.493 --> 00:05:44.200
and they get ground up,
and they get impacted

00:05:44.200 --> 00:05:46.617
with pressure, they can form,

00:05:47.525 --> 00:05:50.115
they can form limestone.

00:05:50.115 --> 00:05:53.148
So this right over here is limestone.

00:05:53.148 --> 00:05:53.981
Limestone.

00:05:55.460 --> 00:05:59.781
But once again, it was
formed from carbon dioxide

00:05:59.781 --> 00:06:01.164
being absorbed into the ocean,

00:06:01.164 --> 00:06:04.424
living things using that calcium,

00:06:04.424 --> 00:06:06.700
using that calcium carbonate,

00:06:06.700 --> 00:06:08.587
the carbonate in conjunction with calcium,

00:06:08.587 --> 00:06:10.507
in order to form these
shells, which get ground down,

00:06:10.507 --> 00:06:14.347
and it actually forms
these rock structures.

00:06:14.347 --> 00:06:16.327
You can have situations,

00:06:16.327 --> 00:06:19.313
you can have situations
where living things,

00:06:19.313 --> 00:06:21.178
whether we're talking about
the autotrophs like plants,

00:06:21.178 --> 00:06:24.337
or we're talking about things
like me that are eating

00:06:24.337 --> 00:06:26.129
the plants, well, once they
die and there's all this

00:06:26.129 --> 00:06:28.681
organic matter that hasn't
been broken down yet.

00:06:28.681 --> 00:06:30.273
Well, it gets buried in the ground.

00:06:30.273 --> 00:06:31.941
I'll do the plant because it's less morbid

00:06:31.941 --> 00:06:34.332
than showing me dead.

00:06:34.332 --> 00:06:36.060
So let's say this is the plant.

00:06:36.060 --> 00:06:38.205
Well, with enough pressure and time.

00:06:38.205 --> 00:06:40.341
Sometimes in the decomposing process,

00:06:40.341 --> 00:06:42.223
some of the carbon might be released.

00:06:42.223 --> 00:06:44.041
But over time this might be compressed

00:06:44.041 --> 00:06:46.506
and be turned into fossil fuels.

00:06:46.506 --> 00:06:50.151
So when you see oil or when
you are burning gasoline,

00:06:50.151 --> 00:06:53.932
which is really just a
refined part of the oil,

00:06:53.932 --> 00:06:55.866
it is really this organic matter

00:06:55.866 --> 00:06:57.902
that was, that's storing energy

00:06:57.902 --> 00:07:00.518
that plants were able to
store from light energy,

00:07:00.518 --> 00:07:04.406
possibly millions or tens
of millions of years ago.

00:07:04.406 --> 00:07:06.936
But then if you were to take that same,

00:07:06.936 --> 00:07:09.668
if you were to take that
fossil fuel out of the ground,

00:07:09.668 --> 00:07:11.164
which we now do very actively

00:07:11.164 --> 00:07:14.475
in order to power all of the
things that we need to power,

00:07:14.475 --> 00:07:16.156
and you were to burn it.

00:07:16.156 --> 00:07:18.387
So let me see, if I were to.

00:07:18.387 --> 00:07:20.412
Let me just draw an example of that.

00:07:20.412 --> 00:07:22.311
So let's say you just had,

00:07:22.311 --> 00:07:24.728
if you had a canister of oil.

00:07:26.656 --> 00:07:27.820
I'm not gonna do the oil in black

00:07:27.820 --> 00:07:29.823
because you'd have trouble seeing it.

00:07:29.823 --> 00:07:32.317
And if you were to burn it.

00:07:32.317 --> 00:07:33.899
If you were to burn it,

00:07:33.899 --> 00:07:35.149
the process of,

00:07:36.412 --> 00:07:38.249
the process of combustion.

00:07:38.249 --> 00:07:39.786
And this is in general, if
you're burning anything,

00:07:39.786 --> 00:07:41.864
it doesn't just have to be oil.

00:07:41.864 --> 00:07:44.528
It could be burning a piece of wood.

00:07:44.528 --> 00:07:47.749
You're taking that organic matter,

00:07:47.749 --> 00:07:49.432
those carbon-carbon bonds,

00:07:49.432 --> 00:07:50.846
and in some ways you can say you're doing

00:07:50.846 --> 00:07:53.500
the reverse of the photosynthesis process.

00:07:53.500 --> 00:07:55.590
You're breaking it down,
and in that process,

00:07:55.590 --> 00:07:57.991
you're releasing that carbon,
and it's getting released

00:07:57.991 --> 00:07:59.158
in the form of

00:08:00.186 --> 00:08:01.887
carbon dioxide.

00:08:01.887 --> 00:08:04.174
Carbon dioxide, which in theory

00:08:04.174 --> 00:08:06.693
could then be fixed once again.

00:08:06.693 --> 00:08:09.309
So the general idea,
autotrophs like plants,

00:08:09.309 --> 00:08:13.227
when they photosynthesize,
they can fix that carbon.

00:08:13.227 --> 00:08:15.483
And then it could either be burnt,

00:08:15.483 --> 00:08:17.825
and a combustion process can release

00:08:17.825 --> 00:08:19.793
that carbon back into the atmosphere,

00:08:19.793 --> 00:08:24.040
or you could have other
animals eating that plant.

00:08:24.040 --> 00:08:26.965
And then, as they
metabolize, as they break

00:08:26.965 --> 00:08:29.838
these carbon-carbon
bonds to power themselves

00:08:29.838 --> 00:08:31.660
or just do whatever they need to do,

00:08:31.660 --> 00:08:34.743
that also can release carbon dioxide.


Motivations for English colonization

WEBVTT
Kind: captions
Language: en

00:00:00.439 --> 00:00:01.481
- [Instructor] In the last video,

00:00:01.481 --> 00:00:03.872
we discussed why it took England

00:00:03.872 --> 00:00:07.701
another 100 years to start colonizing

00:00:07.701 --> 00:00:10.545
the New World after Christopher Columbus

00:00:10.545 --> 00:00:13.255
first set foot in Hispaniola.

00:00:13.255 --> 00:00:17.422
Among those reasons was conflict
within the United Kingdom,

00:00:18.474 --> 00:00:20.727
colonial projects closer to home,

00:00:20.727 --> 00:00:22.312
specifically Ireland,

00:00:22.312 --> 00:00:25.979
and economic depression
that prevented England

00:00:25.979 --> 00:00:29.185
from taking much time to
look outside its borders

00:00:29.185 --> 00:00:31.106
to the broader world.

00:00:31.106 --> 00:00:32.868
In this video, I'm gonna walk about

00:00:32.868 --> 00:00:37.003
what led England to finally
get in the colonial game.

00:00:37.003 --> 00:00:38.865
So what changes that allows England

00:00:38.865 --> 00:00:41.316
to become a premier colonial empire

00:00:41.316 --> 00:00:43.772
and go on to found what will be

00:00:43.772 --> 00:00:45.664
the United States of America,

00:00:45.664 --> 00:00:48.501
today even an English speaking country?

00:00:48.501 --> 00:00:49.827
Well, some of these factors kind of

00:00:49.827 --> 00:00:51.822
turn to their advantage.

00:00:51.822 --> 00:00:54.424
Once the internal religious conflict

00:00:54.424 --> 00:00:56.268
has been sorted out,

00:00:56.268 --> 00:00:59.083
turning England into a Protestant nation,

00:00:59.083 --> 00:01:01.442
they turn some of that animus outward

00:01:01.442 --> 00:01:03.978
to Spain, a Catholic nation,

00:01:03.978 --> 00:01:08.803
and they feel that they
have to compete with Spain

00:01:08.803 --> 00:01:09.636
for riches

00:01:13.005 --> 00:01:14.172
and for souls.

00:01:17.998 --> 00:01:20.278
So certainly, the
Protestant nation of England

00:01:20.278 --> 00:01:21.777
doesn't wanna be left behind

00:01:21.777 --> 00:01:24.713
anymore than it already has been by Spain,

00:01:24.713 --> 00:01:27.884
which has clearly been
reaping great riches

00:01:27.884 --> 00:01:31.051
from the New World in the form of gold

00:01:32.173 --> 00:01:36.143
down here in Mexico and Central America

00:01:36.143 --> 00:01:38.560
and sugar, the Sugar Islands,

00:01:41.236 --> 00:01:42.925
and they also don't wanna be one upped

00:01:42.925 --> 00:01:45.118
by the Catholic nation of France,

00:01:45.118 --> 00:01:48.868
which has been reaping
some excellent profits

00:01:50.053 --> 00:01:52.410
trading with Native
Americans up in the region

00:01:52.410 --> 00:01:55.954
which is today New York and Canada,

00:01:55.954 --> 00:01:58.685
and they're getting furs.

00:01:58.685 --> 00:02:01.808
So there's clearly a lot to be had

00:02:01.808 --> 00:02:02.906
in the new world

00:02:02.906 --> 00:02:07.399
and a lot of Catholics to
triumph over in having it.

00:02:07.399 --> 00:02:10.847
Another thing that allows England to join

00:02:10.847 --> 00:02:12.976
the imperial game in the New World

00:02:12.976 --> 00:02:16.643
is the invention of the
Joint Stock Company.

00:02:19.489 --> 00:02:24.221
Now, Joint Stock Companies
were kind of the precursor,

00:02:24.221 --> 00:02:25.899
I mean, more than kind of the precursor,

00:02:25.899 --> 00:02:30.066
really the precursor to
the modern day corporation,

00:02:31.059 --> 00:02:32.835
and like modern day corporations,

00:02:32.835 --> 00:02:35.091
what they did was kind of

00:02:35.091 --> 00:02:38.547
spread both the riches and also the risk

00:02:38.547 --> 00:02:42.331
of any kind of
entrepreneurial undertaking.

00:02:42.331 --> 00:02:44.184
And what I mean by this is that

00:02:44.184 --> 00:02:46.478
people could buy shares

00:02:46.478 --> 00:02:48.803
in a Joint Stock Company,

00:02:48.803 --> 00:02:50.872
and those shares were kind of divested

00:02:50.872 --> 00:02:52.931
from your personal wealth.

00:02:52.931 --> 00:02:55.156
So you could invest in something that,

00:02:55.156 --> 00:02:56.500
if it went belly up,

00:02:56.500 --> 00:02:58.053
wouldn't necessarily ruin you

00:02:58.053 --> 00:02:59.818
'cause you just had a few shares.

00:02:59.818 --> 00:03:03.015
So it's, you know, similar
to the stock market today,

00:03:03.015 --> 00:03:04.874
a very early version of that.

00:03:04.874 --> 00:03:07.492
So these Joint Stock Companies meant that

00:03:07.492 --> 00:03:10.409
adventurers, people seeking wealth,

00:03:11.514 --> 00:03:15.083
could go out to the
New World, for example,

00:03:15.083 --> 00:03:16.867
with many different backers,

00:03:16.867 --> 00:03:19.276
the risk spread across all of them,

00:03:19.276 --> 00:03:22.859
and try to make profit
for their investors.

00:03:24.930 --> 00:03:28.312
So many what we would call promoters

00:03:28.312 --> 00:03:29.645
of the New World

00:03:33.055 --> 00:03:36.006
tried to drum up interest in expeditions

00:03:36.006 --> 00:03:37.246
to the New World.

00:03:37.246 --> 00:03:40.580
Now, everybody knows that
Spain is making a killing

00:03:40.580 --> 00:03:42.333
from gold and sugar,

00:03:42.333 --> 00:03:45.055
and so they're saying, "Well,
maybe private individuals

00:03:45.055 --> 00:03:48.144
"with the blessing,
though not the sponsorship

00:03:48.144 --> 00:03:51.226
"of the crown can go to the New World

00:03:51.226 --> 00:03:53.798
"and start extracting
some of these resources

00:03:53.798 --> 00:03:56.408
"and start creating wealth
for their investors."

00:03:56.408 --> 00:03:59.278
And so England issues several charters

00:03:59.278 --> 00:04:02.050
to Joint Stock Companies that are still

00:04:02.050 --> 00:04:04.300
familiar names to us today.

00:04:05.500 --> 00:04:08.500
For example, the East India Company,

00:04:09.371 --> 00:04:12.403
which Americans know best as the company

00:04:12.403 --> 00:04:16.070
that supplied the tea
that Bostonians dumped

00:04:17.065 --> 00:04:20.762
into Boston Harbor slightly
before the American Revolution,

00:04:20.762 --> 00:04:22.858
but the one that plays the most role

00:04:22.858 --> 00:04:25.470
in the early founding of the United States

00:04:25.470 --> 00:04:27.470
is the Virginia Company,

00:04:28.889 --> 00:04:31.484
and it's under the auspices
of the Virginia Company

00:04:31.484 --> 00:04:36.056
that explorers like John
Smith head to Virginia

00:04:36.056 --> 00:04:39.889
and Virginia is named
for Elizabeth the First,

00:04:41.369 --> 00:04:42.725
Henry the Eighth's daughter,

00:04:42.725 --> 00:04:45.300
who never married, and
therefore was said to be

00:04:45.300 --> 00:04:46.765
the Virgin Queen,

00:04:46.765 --> 00:04:50.283
so a new land named
after her was Virginia.

00:04:50.283 --> 00:04:52.564
Now, we'll talk more
about the Virginia Company

00:04:52.564 --> 00:04:53.655
in the next video,

00:04:53.655 --> 00:04:57.207
but the last thing I wanna
say about what prompted

00:04:57.207 --> 00:05:01.672
England to join the imperial
game in the New World

00:05:01.672 --> 00:05:06.299
was that England was having
a serious economic depression

00:05:06.299 --> 00:05:08.132
and some real poverty.

00:05:10.124 --> 00:05:14.426
Now remember that England
was a highly classed society

00:05:14.426 --> 00:05:16.759
with aristocracy and gentry,

00:05:19.219 --> 00:05:22.373
and these were inherited roles, right?

00:05:22.373 --> 00:05:24.166
You couldn't rise

00:05:24.166 --> 00:05:26.883
to be among these ranks, generally.

00:05:26.883 --> 00:05:30.418
So, you know, about 95% of the population

00:05:30.418 --> 00:05:32.984
didn't belong to either of these groups,

00:05:32.984 --> 00:05:35.202
and a strong majority of those

00:05:35.202 --> 00:05:38.145
were in dire poverty in the 1500s

00:05:38.145 --> 00:05:39.548
and early 1600s,

00:05:39.548 --> 00:05:42.474
and there were a number
of reasons for this.

00:05:42.474 --> 00:05:45.424
The market for wool, which England,

00:05:45.424 --> 00:05:49.257
being a major textile
producer, had collapsed,

00:05:51.854 --> 00:05:54.224
so many people who had been

00:05:54.224 --> 00:05:57.933
wool producers were in dire straits.

00:05:57.933 --> 00:06:00.540
In fact, many of them were Puritans,

00:06:00.540 --> 00:06:02.886
and we'll see more about
what happens to the Puritans

00:06:02.886 --> 00:06:05.212
who leave England in another video,

00:06:05.212 --> 00:06:08.348
and there's a process going
on in this time period

00:06:08.348 --> 00:06:09.931
known as enclosure,

00:06:12.621 --> 00:06:15.053
the Enclosure Movement.

00:06:15.053 --> 00:06:18.536
And what enclosure meant is
kind of what it sounds like,

00:06:18.536 --> 00:06:21.444
which is that early English towns

00:06:21.444 --> 00:06:24.833
and manor houses were
kind of set up to have,

00:06:24.833 --> 00:06:27.180
you know, the house.

00:06:27.180 --> 00:06:30.012
That's the big manor house,

00:06:30.012 --> 00:06:32.165
so just bear with me and imagine here,

00:06:32.165 --> 00:06:35.165
and then they might have some forest

00:06:37.610 --> 00:06:40.277
filled with a nice deer to hunt,

00:06:41.751 --> 00:06:45.918
and then they might have
some nice fields, just grass,

00:06:48.719 --> 00:06:52.428
and these were kind of
considered common lands.

00:06:52.428 --> 00:06:54.753
So if you were a peasant, for example,

00:06:54.753 --> 00:06:57.333
you might graze your cows

00:06:57.333 --> 00:06:58.758
on these common lands.

00:06:58.758 --> 00:07:01.397
You might go hunting in the forest.

00:07:01.397 --> 00:07:03.495
Well, in this time period,

00:07:03.495 --> 00:07:07.741
these great English lords
started to close off,

00:07:07.741 --> 00:07:09.991
enclose these common lands.

00:07:11.361 --> 00:07:13.598
So they'd fence them off.

00:07:13.598 --> 00:07:16.901
This kind of makes
sense to our modern idea

00:07:16.901 --> 00:07:19.954
of property holding, right?

00:07:19.954 --> 00:07:23.721
It makes us understand who owns what thing

00:07:23.721 --> 00:07:26.153
and how it gets deeded, et cetera,

00:07:26.153 --> 00:07:27.789
but for very poor people,

00:07:27.789 --> 00:07:30.338
this was a huge transition

00:07:30.338 --> 00:07:32.305
because now they didn't have a place

00:07:32.305 --> 00:07:34.623
to raise their livestock.

00:07:34.623 --> 00:07:39.011
They didn't have a source
of hunting, protein,

00:07:39.011 --> 00:07:42.018
so it made people who
were already on the edge

00:07:42.018 --> 00:07:44.091
of poverty extremely poor.

00:07:44.091 --> 00:07:45.746
It was a very difficult time

00:07:45.746 --> 00:07:48.242
if you were already kind of living

00:07:48.242 --> 00:07:52.002
in the foraging or small farming aspect

00:07:52.002 --> 00:07:53.285
of English life.

00:07:53.285 --> 00:07:57.697
And so, because of this Enclosure
Movement and depression,

00:07:57.697 --> 00:08:00.697
crime rates are going up in England,

00:08:01.981 --> 00:08:05.934
and this is a time when theft
is still a capital crime.

00:08:05.934 --> 00:08:08.472
So if you're starving and
you steal something to eat,

00:08:08.472 --> 00:08:10.104
you could be hanged,

00:08:10.104 --> 00:08:12.993
and so many of the English gentry,

00:08:12.993 --> 00:08:14.445
the people in Parliament,

00:08:14.445 --> 00:08:15.641
are looking around and saying,

00:08:15.641 --> 00:08:16.529
"Alright, what's going on?

00:08:16.529 --> 00:08:18.565
"Are we having a moral crisis?"

00:08:18.565 --> 00:08:20.454
Because they don't think in terms

00:08:20.454 --> 00:08:22.137
that say, "Alright, many people are poor.

00:08:22.137 --> 00:08:23.456
"Maybe they're going to steal."

00:08:23.456 --> 00:08:25.585
Instead, they're saying,
"Why are people stealing?

00:08:25.585 --> 00:08:26.863
"What's wrong with people?"

00:08:26.863 --> 00:08:30.577
And so they think of this
as surplus population,

00:08:30.577 --> 00:08:33.928
say there are too many people in England.

00:08:33.928 --> 00:08:36.592
Now this is patently untrue

00:08:36.592 --> 00:08:38.658
because there are way more people

00:08:38.658 --> 00:08:40.139
living in London today

00:08:40.139 --> 00:08:43.145
than there were in all of
England at that time period,

00:08:43.145 --> 00:08:44.921
but the English Parliament,

00:08:44.921 --> 00:08:47.297
sort of major thinkers in England,

00:08:47.297 --> 00:08:50.094
start to think that there are
too many people in England.

00:08:50.094 --> 00:08:51.639
There are just too many people

00:08:51.639 --> 00:08:54.121
for having enough stuff to go around,

00:08:54.121 --> 00:08:55.789
and so they start wondering.

00:08:55.789 --> 00:08:57.769
Maybe these people should go elsewhere.

00:08:57.769 --> 00:09:00.352
Maybe they should go to colonies

00:09:00.352 --> 00:09:02.708
where maybe they can buy more goods,

00:09:02.708 --> 00:09:04.902
produce more raw materials,

00:09:04.902 --> 00:09:08.636
and find a different place
in the social structure

00:09:08.636 --> 00:09:10.244
and economy of England,

00:09:10.244 --> 00:09:11.839
and that starts to come true

00:09:11.839 --> 00:09:16.635
when the Virginia Company
sets off for Jamestown,

00:09:16.635 --> 00:09:18.968
which they'll reach in 1607,

00:09:21.436 --> 00:09:23.591
and we'll talk about
that in the next video.


England in the Age of Exploration

WEBVTT
Kind: captions
Language: en

00:00:00.000 --> 00:00:01.421
- [Instructor] I think
there's a strong argument

00:00:01.421 --> 00:00:02.926
to be made that England was the most

00:00:02.926 --> 00:00:06.176
powerful and successful imperial nation

00:00:07.048 --> 00:00:11.032
of all time, but when you look back to the

00:00:11.032 --> 00:00:14.661
Age of Exploration, it
becomes clear that England

00:00:14.661 --> 00:00:19.029
was actually pretty late
to the imperial game.

00:00:19.029 --> 00:00:21.364
As we know, Christopher Columbus,

00:00:21.364 --> 00:00:24.203
backed by Spain, had arrived in

00:00:24.203 --> 00:00:27.203
Hispaniola in the New World in 1492.

00:00:30.513 --> 00:00:33.346
He was the first European to start

00:00:34.514 --> 00:00:36.366
a colony in the New World.

00:00:36.366 --> 00:00:39.793
England, by contrast, didn't actually have

00:00:39.793 --> 00:00:42.695
a successful colonial venture in the

00:00:42.695 --> 00:00:45.695
New World until 1607 with Jamestown.

00:00:48.066 --> 00:00:50.220
Now from this distance it doesn't look

00:00:50.220 --> 00:00:54.220
that far behind, but this
is more than 100 years

00:00:56.350 --> 00:00:59.723
later than Spain's
first colonial ventures.

00:00:59.723 --> 00:01:01.893
So what was England up to?

00:01:01.893 --> 00:01:05.407
Why were they so late
in the colonial game?

00:01:05.407 --> 00:01:07.264
That's what I'd like to
take a closer look at

00:01:07.264 --> 00:01:08.995
in this video, and I'll also talk

00:01:08.995 --> 00:01:11.460
a little bit more about what conditions

00:01:11.460 --> 00:01:15.627
in England led that nation
to start New World colonies.

00:01:17.050 --> 00:01:20.073
Now I think the biggest reason why England

00:01:20.073 --> 00:01:22.833
waited another 100 years to have a

00:01:22.833 --> 00:01:25.154
New World colony is that England had

00:01:25.154 --> 00:01:26.993
its own problems, and it had a number

00:01:26.993 --> 00:01:28.954
of problems in this time period,

00:01:28.954 --> 00:01:32.572
and we're talking about the 1500s here.

00:01:32.572 --> 00:01:35.695
And the first of these
was ongoing conflict

00:01:35.695 --> 00:01:39.085
between Catholics and
Protestants in England.

00:01:39.085 --> 00:01:41.038
Now this is a very long story.

00:01:41.038 --> 00:01:43.188
I don't have time to
do justice to it here,

00:01:43.188 --> 00:01:45.412
but suffice it to say
that the trouble started

00:01:45.412 --> 00:01:49.204
with Henry VIII, who we know from his

00:01:49.204 --> 00:01:51.940
many wives and many beheadings,

00:01:51.940 --> 00:01:55.417
and Henry VIII broke away
from the Catholic Church

00:01:55.417 --> 00:01:57.662
in Rome to start his own church,

00:01:57.662 --> 00:02:00.592
the Church of England, also
known as the Anglican Church.

00:02:00.592 --> 00:02:02.513
Now this is a Protestant religion.

00:02:02.513 --> 00:02:05.573
I'm gonna put P here for Protestant.

00:02:05.573 --> 00:02:08.740
Now Henry had two daughters, Elizabeth

00:02:10.461 --> 00:02:12.961
who like him was a Protestant,

00:02:14.293 --> 00:02:18.210
and Mary, who was a
Catholic, and Mary occupied

00:02:20.028 --> 00:02:21.537
the throne for a number of years,

00:02:21.537 --> 00:02:24.181
but Elizabeth managed to
wrest it away from her

00:02:24.181 --> 00:02:27.207
and once Elizabeth was on the throne

00:02:27.207 --> 00:02:31.374
as Elizabeth I, England
became a Protestant nation.

00:02:34.786 --> 00:02:37.623
So it's hard to be
involved in world affairs

00:02:37.623 --> 00:02:40.392
when you've got kind of
a crisis of succession

00:02:40.392 --> 00:02:44.559
going on, so one factor
here is religious conflict.

00:02:50.474 --> 00:02:52.736
Another reason why England is not headed

00:02:52.736 --> 00:02:54.679
over to the New World is that they have

00:02:54.679 --> 00:02:58.664
colonial problems closer
to home in Ireland.

00:02:58.664 --> 00:03:02.099
England is trying to, and will succeed at,

00:03:02.099 --> 00:03:05.432
subduing Ireland as one of its colonies,

00:03:07.581 --> 00:03:10.169
and they're undertaking a very bloody

00:03:10.169 --> 00:03:12.877
and costly war, and they think of this

00:03:12.877 --> 00:03:16.158
Catholic Irish population almost as

00:03:16.158 --> 00:03:18.462
barbarian savages who don't know

00:03:18.462 --> 00:03:21.286
what's good for them and in
the opinion of the English,

00:03:21.286 --> 00:03:22.915
what's good for them is English rule

00:03:22.915 --> 00:03:24.572
and Protestantism, when of course

00:03:24.572 --> 00:03:26.666
what the Irish really want is self rule

00:03:26.666 --> 00:03:28.496
and to be left alone, but they use

00:03:28.496 --> 00:03:32.433
very brutal tactics against the Irish,

00:03:32.433 --> 00:03:34.619
and we'll kind of see that again

00:03:34.619 --> 00:03:37.284
when they're met with another hostile

00:03:37.284 --> 00:03:40.456
colonial population in North America.

00:03:40.456 --> 00:03:42.296
Another issue England is dealing with

00:03:42.296 --> 00:03:44.213
is economic depression.

00:03:45.247 --> 00:03:47.556
The Crown doesn't have a lot of money

00:03:47.556 --> 00:03:50.277
and there's a great deal of crime

00:03:50.277 --> 00:03:53.179
and poverty throughout the nation,

00:03:53.179 --> 00:03:56.897
so while the Crown can't actually afford

00:03:56.897 --> 00:04:00.401
to sponsor colonial exploits the way

00:04:00.401 --> 00:04:03.450
that Spain sponsored Columbus, they still

00:04:03.450 --> 00:04:05.700
managed to get some riches out

00:04:05.700 --> 00:04:08.195
of the New World by giving ship captains

00:04:08.195 --> 00:04:10.862
license to plunder Spanish ships

00:04:12.520 --> 00:04:14.931
coming back with New World riches,

00:04:14.931 --> 00:04:17.185
and these were called privateers,

00:04:17.185 --> 00:04:20.602
the most famous of them here is this man,

00:04:22.044 --> 00:04:25.919
Sir Francis Drake, and
really, privateers are

00:04:25.919 --> 00:04:28.893
just pirates with a fancy name,

00:04:28.893 --> 00:04:31.931
but the logic here was, why bother

00:04:31.931 --> 00:04:35.264
trying to set up a colony here in Mexico

00:04:36.427 --> 00:04:39.260
or South America, the West Indies,

00:04:40.567 --> 00:04:43.848
and do all the work of setting up housing

00:04:43.848 --> 00:04:46.846
and trying to tame laborers and mining,

00:04:46.846 --> 00:04:49.357
when instead you could just let the

00:04:49.357 --> 00:04:52.116
Spanish do all of that and then put that

00:04:52.116 --> 00:04:55.949
gold on a ship and then
use your awesome navy,

00:04:57.261 --> 00:05:00.981
'cause England is growing
a very awesome navy,

00:05:00.981 --> 00:05:02.814
to steal those riches.

00:05:04.125 --> 00:05:07.706
So England doesn't have a strong incentive

00:05:07.706 --> 00:05:10.348
to do all the labor when they can

00:05:10.348 --> 00:05:13.664
just steal it from the
ships along the way.

00:05:13.664 --> 00:05:14.903
Alright, those are some of the reasons

00:05:14.903 --> 00:05:17.572
why it took England so long to start

00:05:17.572 --> 00:05:19.892
colonization in North America.

00:05:19.892 --> 00:05:21.436
In the next video I'll talk about

00:05:21.436 --> 00:05:24.765
the factors that led England to finally

00:05:24.765 --> 00:05:27.003
join the race for New World colonies.


Khan Academy’s 100&Change proposal: World-class diplomas for anyone, anywhere

WEBVTT
Kind: captions
Language: en

00:00:00.487 --> 00:00:01.802
- Hi, I'm Sal Khan.

00:00:01.802 --> 00:00:03.201
Founder of the Khan Academy.

00:00:03.201 --> 00:00:05.109
We're a not for profit with a mission

00:00:05.109 --> 00:00:07.331
of providing a free world-class education

00:00:07.331 --> 00:00:09.668
for anyone anywhere.

00:00:09.668 --> 00:00:11.116
There are tens of millions of people

00:00:11.116 --> 00:00:12.710
learning on Khan Academy

00:00:12.710 --> 00:00:14.659
who wanna prove what they know,

00:00:14.659 --> 00:00:16.564
who wanna show the world
they're just as capable

00:00:16.564 --> 00:00:19.102
as folks with more traditional diplomas.

00:00:19.102 --> 00:00:20.612
So we're gonna make a bridge

00:00:20.612 --> 00:00:22.934
between learning on Khan Academy

00:00:22.934 --> 00:00:25.526
and real economic opportunity.

00:00:25.526 --> 00:00:27.848
To do that, we're gonna work with

00:00:27.848 --> 00:00:30.807
employers and universities
all over the world

00:00:30.807 --> 00:00:33.364
to identify the skills
that people need most

00:00:33.364 --> 00:00:34.653
to be successful.

00:00:34.653 --> 00:00:36.735
Then we'll build the content and the tools

00:00:36.735 --> 00:00:39.216
that allow anyone,
starting from any level,

00:00:39.216 --> 00:00:41.029
to learn those skills.

00:00:41.029 --> 00:00:44.419
To build the bridge between
the learning of the skills

00:00:44.419 --> 00:00:46.722
and the opportunities
where you can apply them,

00:00:46.722 --> 00:00:49.749
we're gonna create globally
recognized diplomas.

00:00:49.749 --> 00:00:51.287
We're confident we can do this,

00:00:51.287 --> 00:00:53.104
because we already have
the reach and credibility

00:00:53.104 --> 00:00:56.012
with over 100 million
learners all over the world,

00:00:56.012 --> 00:00:58.226
and we have partnerships in assessment,

00:00:58.226 --> 00:01:01.242
in industry, and in higher education.

00:01:01.242 --> 00:01:03.828
Together, I believe that we can do this.

00:01:03.828 --> 00:01:04.937
And when it happens,

00:01:04.937 --> 00:01:07.551
it's going to bring hope and opportunity

00:01:07.551 --> 00:01:10.657
to people all over the world.

00:01:10.657 --> 00:01:12.005
- When you see Khan Academy,

00:01:12.005 --> 00:01:13.897
it gives you hope that there is

00:01:13.897 --> 00:01:15.469
someone who can bring change,

00:01:15.469 --> 00:01:18.586
and I'm hopeful that they
will be able to reach to

00:01:18.586 --> 00:01:20.402
hundreds and thousands

00:01:20.402 --> 00:01:22.731
or millions of children across the world,

00:01:22.731 --> 00:01:26.624
and allow them and help
them to be empowered.

00:01:26.624 --> 00:01:28.124
I believe in that.