There are 3 billion billion billion
prochlorococcus in the ocean
That’s 10 to the 27th, or an octillion
This picoplankton is so tiny --
a drop of seawater contains
20,000 cells -- but together
their mass adds up to that of
220 million Volkswagen beetles
and they cover a vast swath of the planet
living between 40N and 40S
Since their discovery in the 1980s,
these ocean-going microbes
have opened up world after world
to researchers--
helping us understand microbes,
oceans, ecosystems,
even the rise of animals on the planet.
Though prochlorococcus, like other microbes,
reproduces by dividing in half,
not all of them are genetically identical.
Instead, over time they have separated into
ecotypes --
strains that contain different genes
better adapted to their environment.
At the surface of the ocean,
where nutrients are scarce,
high-light adapted prochlorococcus
have a sleek genome of about 1700 genes
and can still grow on almost pure seawater,
carbon dioxide and sunlight.
In low light, as deep as 200 meters,
their genomes bulk up to
as much as 2700 genes
to help them capture light
and nutrients in the deep water.
but there aren’t only two ecotypes
of Prochlorococcus,
there are thousands -
each with its own genetic "repertoire”
So far, researchers have estimated there
may be more than 80,000 different genes
in the “Prochlorococcus collective" --
that’s four times as many
genes as we have
Even more abundant than prochlorococcus
are their vesicles
These are tiny, membrane-bound packets
that contain DNA, RNA, and proteins.
They are thought to act as a food source,
decoys against viruses,
and a way of sharing genes
If each prochlorococcus buds off just two
vesicles --
we’re talking many more more "Volkswagens’’ worth
of prochlorococcus
products in the ocean .
Prochlorococcus’ sheer abundance
and photosynthetic talents
make it a huge player
in ocean food webs and climate.
Recent analysis of the evolution
of their metabolism
suggests that as the genome became 
more and more streamlined
they lost certain pathways,
causing them to offload carbon,
and building up a hospitable environment 
for other ocean critters
And new research suggests that
as this population grew,
it helped fuel the explosion
of early life in the oceans
and the rise of oxygen in the
earth’s atmosphere
giving these tiny life forms a chance
to shape something much bigger
