Natural Selection and Evolution
What is Evolution?
Evolution: is the process by which different
kinds of living organisms are thought to have
developed and diversified from earlier forms
during the history of the Earth
Charles Darwin is the father of evolution.
Charles Darwin proposed a mechanism for evolution,
called natural selection.
Natural Selection.
Natural selection is organisms that have best
adapted to an environment survive and reproduce
more than others.
The 4 Steps.
Darwin's Theory of Natural Selection occurs
in four steps: Overproduction, Variation,
Competition , and of course Selection.
Overproduction.
Overproduction is when each species produces
more offspring that can survive.
Variation.
Variation is when each individual has a unique
combination of inherited traits, such as an
adaptation which is an inherited trait that
increases an organism's chances of survival
.
Variation is important because the environment
changes.
The more variation within a species, the more
likely it will survive.
An Example is if everyone is the same, they
are all vulnerable to the same environmental
changes or diseases.
The more variation of types of species in
an habitat, the more likely at least some
will survive.
An example of this is mammals replacing dinosaurs.
Competition is when individuals compete for
limited resources such as food, water, space,
and or mates.
Natural selection occurs through " Survival
of the fittest" which is also natural selection.
Not all individuals survive to adulthood.
Selection is when individuals with the best
traits/ adaptations will survive and have
the opportunity to pass on it's traits to
offspring.
Natural selection acts on the phenotype (physical
appearance), not the genotype (genetic makeup).An
example of this is when a predator finds its
prey, it is due to the prey's physical characteristics,
like color or slow speed, not the alleles.
Individuals with traits that are not well
suited to their environment either die or
leave few offspring.Evolution occurs when
good traits build up in a population over
many generations and bad traits are eliminated
by the death of the individuals.
Descent With Modification.
Descent with modification is each living species
that has descended, with changes from other
species over time.Common Descent.
All living living organisms are related to
one another.
That concludes this video.
