How Bacteria Talk
Bacteria are the oldest living organisms on the earth.
They've been here for billions of years,
what they are are single-celled microscopic organisms.
So they are one cell and they have this
that they only have one piece of DNA.
They have very few genes,
information to encode all of the traits that they carry out.
And the way bacteria make a living
that they consume nutrients from the environment,
they grow to twice their size, they cut
themselves down in the middle,
and one cell becomes two, and so on and so on.
They just grow
and divide, and grow and divide -- so a kind of boring life,
except that what I would argue is that
an amazing interaction with these critters.
I know you guys think of yourself as humans, and this is sort of how I think of you.
This man is
supposed to represent
a generic human being,
and all of the circles in that man are all of the cells
that make up your body.
There is about a trillion human cells that make each one of us
are and able to do all the things that we do,
but you have 10 trillion bacterial cells
in you or on
you at any moment in your life.
So, 10 times more bacterial cells
than human cells on a human
And of course it's the DNA that counts,
so here's all the A, T, Gs and Cs
that make up
your genetic code, and give you all your charming characteristics.
You have about 30,000 genes.
Well it turns out you have 100 times more bacterial genes
playing a role in you or on you all of
At the best, you're 10 percent human,
but more likely about one percent human,
depending on which of these metrics you like.
I know you think of yourself as human beings,
I think of you as 90 or 99 percent bacterial.
These bacteria are not passive riders,
these are incredibly important, they keep us alive.
cover us in an invisible body armor
that keeps environmental insults out
so that we stay healthy.
They digest our food, they make our vitamins,
they actually educate your immune system
keep bad microbes out.
So they do all these amazing things
that help us and are vital for keeping
and they never get any press for that.
But they get a lot of press because they do a lot of
terrible things as well.
So, there's all kinds of bacteria on the Earth
that have no business being in
you or on you at any time,
and if they are, they make you incredibly sick.
And so, the question for my lab is whether you want to think about all the
good things that
bacteria do, or all the bad things that bacteria do.
The question we had is how could they do
anything at all?
I mean they're incredibly small,
you have to have a microscope to see one.
live this sort of boring life where they grow and divide,
and they've always been considered to be
these asocial reclusive organisms.
And so it seemed to us that they are just too small to have an
on the environment
if they simply act as individuals.
And so we wanted to think if there