Wow! It's so great to be here!
I'm so happy to see you guys.
Arguably, one of the most disruptive events in the history of the planet
has got to be the rise of the animal kingdom.
Definitely.
I mean, here is Earth, simmering along, minding its own, single-cell business
for nearly four billion years, and some group of restless cells
comes together and decides to become multi-cellular metazoa and well...
the neighborhood's never been the same since, has it?
And we have a remarkable diversity of animals
with whom we share the planet, don't we?
Millions of species swimming, scurrying, slipping around,
seemingly endless forms, most beautiful.
How do you make sense of it all?
Well, it may just help to know that 99% of all animal life
fall into just eight major groups.
Eight body plans.
Scientists call these "phyla".
And if you know these eight plans, you've got an incredible grasp
of the constraints and freedoms of the animal world.
And there's something special about these eight phyla.
While species go extinct every day, these phyla have prevailed and persisted
for over 550 million years.
Every mass extinction the planet has mustered,
they've managed to make it through.
So who are these amazing methuselahs?
Let's look at plan 1: the sponges.
These are Earth's first true blue animals.
They scripted that vital language for single cells to work together
with other cells for a common cause, in this case, pumping.
So hail Mother Sponge!
It sucks, it pumps, it's a mother of us all.
And you know, some of us have a problem being descendants from apes. Well...
So, plan number 2: the cnidarians: anemones, jellies and corals.
These were the first guys to put muscle and nerve together into a body plan,
and with that, we get animal behavior.
They're characterized by a round body, radially symmetric,
and little stinging cells called "cnidae".
If any of you have been stung by a jellyfish,
you know what I mean, they pack a punch.
So these were the first guys to coin animal behavior.
Okay, our next body plan – look at those little anemones –
– are the platyhelminthes. Very contemptuous phylum,
many biologists don't feel it's a true phylum,
but comprised of many different phyla,
and so right now the animal tree is being shaken right at its roots.
But what you need to take home from this representative body plan is that,
here we see the first representation of a left-right symmetry.
Bilateral symmetry, which all complex animals have.
And a concentration of sense organs right at one part of the body.
The makings of a head,
and with a head you can have directed animal behavior,
and hunting.
This is also where we think animals first started
to get a threshold level of genetic complexity
and pole body patterning genes called Hox genes.
And that, coupled with the right environmental conditions,
and serendipitous fossilization,
catalyzed its incredible radiation of animal diversity
best known from the Cambrian explosion.
Also in this group is, we think, the appearance of the first penis.
And as I've raised that subject,
I have to talk about one modern representative, the turbellarians.
These guys have not one, but two penises that are hypodermic.
And they joust with them.
And the first one to jab its sperm into the other gets to be the boy,
while the jab-ee gets to be the girl.
And this remarkable behavior is aptly called penis-fencing.
Go figure. (Laughter)
OK, moving on to the fourth: we have the annelids.
These animals have a body cavity called the coelom.
And they're known by having these little rings running down their bodies.
What these guys brought into the animal world
was the ability to penetrate into the soil, bring oxygen in and release carbon dioxide.
And releasing carbon dioxide actually helped
to heat the planet up and make it more livable for other life.
Now we've got too much CO2, but at the time,
this was really an important thing that the annelids brought to the planet –
Bioturbation. Okay.
Our next plan we've got are the mollusks. Amazing phylum.
Tiny little shelled animals to giant squid.
All characterized by a single slimy foot.
And what the mollusks show us, most of them are shelled.
And we can see in the mollusk phylum is this arms race escalation,
with shells becoming more increasingly complex
in response to more complex predation from other phyla,
so they kind of exemplify an arms race escalation,
with some of them actually doing away with the shell completely,
trading it for smarts and psychedelic skin that we see in the squid and the octopus.
And these are the guys who can change color
and texture of their skin in split-seconds,
the rockstars of the mollusk phylum. Gotta love these guys. (Laughter)
And they can even be bipedal!
Okay, our next phylum are the echinoderms, the spiny-skinned guys.
The sea stars, sea urchins, and sea cucumbers.
And they're characterized by an internal skeleton of little plates
that can lock together with very little energy expenditure.
And underneath are these tube feet that allow them to move
and shuttle food to their central mouth.
Now, these are a complex animal,
but they decided to do away with bilateral symmetry,
they have a five-part symmetry.
And they have no brain.
And they seem like they don't do much, they just sit there on the sea floor.
But you speed them up in timelapse and you see that they're incredibly industrious.
And they actually comprise the bulk of the biomass in the deep sea environment.
Very successful body plan.
Our next one, the true rulers of the planet, the arthropods.
Now, if you look at all the animals, the arthropods comprise the bulk.
Eighty percent are arthropods.
If you added up the biomass of humans, they are 300 times the biomass of all humans.
And most of them are insects!
Did you know that four out of five animals have six legs?
So, these are the first guys that walked out of the ocean
and started to explore at land.
They were the first ones that took to the skies.
100 millions of years before the birds ever thought of doing such a thing.
So, what is the secret to their success?
How are they able to be in every environment imaginable?
Well, it has something to do with that outside skeleton,
their exoskeleton.
And their diversity of appendages down their body,
like a little Swiss army knife.
They can have multiple antennae, multiple legs, multiple wings,
multiple reproductive organs, it's just an amazing attribute
that allows them to infiltrate every habitable space on the planet.
And the last phylum, the chordates.
This is, of course, where we originated over 550 million years ago.
And it's characterized by having a spinal cord,
right there you see in pink, that blossoms into a brain in vertebrates,
and underneath a notochord,
which turns into a bony spinal column in the vertebrates as well.
And this is all the guys that make the silver screen all the time.
The mammals, and the amphibians, and the reptiles, and of course, the fish.
The bulk of the chordates are the fishes.
And these are all the guys we know and love.
And of course, the fish –
that's one of my favorite fish, the mola mola.
And it includes our kin, our land-loving hominids.
These are my little ones.
So that's the basic eight,
and, I think, to recap, why don't we do that with a song?
Alright, you guys ready? Okay.
And now, a song.
The sponges started everything, pumping up a storm,
...among the ruckus, the rest of us was born.
Cnidarians muscled up, mixed nerves into the potion,
and with that quick addition got us brand-new locomotion.
The flattish worm-like hunters got a head and then some traction,
and with some senses and a penis – Oooh! – scored some action.
The shape of life, yeah.
And here we have penis fencing in flagrante delicto.
The shape of life, yeah...
Now, being male and female, that just works out great,
anybody in the world can double as your date.
Then all hell broke loose and the other plans appeared.
The Cambrian exploded, launched the world into high gear.
The annelids took to the dirt and bioturbatin'.
The mollusks took to fighting and arms race escalating.
Echinos said, "The heck with this, we're better off instead
taking life into the slow land, lopping off that head."
Arthros stepped onto the land and ruled, that ain't no mystery,
till bonehead chordates followed and soon would rewrite history.
The shape of life, yeah...
Okay, very good! (Applause)
So why study these mostly slimy, spineless critters
with whom we co-pilot spaceship Earth?
Well, were it not for them,
none of us would be strutting and fretting our ten minutes upon this stage.
It's the animal life and all the life that came before us
and with whom we share this planet that not only set the stage,
but created the very stage for all life to flourish in the future.
And I can't put it any more eloquently than E. O. Wilson, who says:
"Humanity is exalted, not because we are so far above every thing living,
but because knowing them well elevates the very concept of life."
Thank you.
(Applause)