that we're the perfectly evolved species,

but I get constant back pain.

- I go blind in one eye

and then I get migraines and puke for seven hours.

- Every time I explore a new city, I sprain my ankle.

- I got gout.

- Greg's mom gave him a cane.

(laughing)

So today we're going to go on a journey of biology

and evolutionary history to discover

the perfectly evolved human,

starting with your terribly designed feet.

- Apart from being sexually attractive to some people,

for example, Mitch's sexual awakening

was Gaston's foot in "Beauty and the Beast."

- [Mitch] Like Greg!

- (laughs) Our feet are an evolutionary mess.

Early hominids would stay safe from predators

by running into trees.

You can see how your feet

were initially designed to grasp or grab branches.

Please don't put this on WikiFeet, you freaks.

And the way our feet would grip the tree branch

was with numerous complex bones in the feet,

much like the apes and chimps climbing in trees today.

This is why you currently have the absurd amount

of 26 bones in your feet.

26 bones is for gripping.

That is way too many for just walking around.

So the perfectly evolved human needs the ostrich foot.

Other than humans, birds are the only other

animal on earth that are truly bipedal.

Human started walking upright 5 million years ago,

whereas birds have been running around on two feet

for 250 million years.

If you look at this diagram,

you see that birds evolved hundreds of millions of years ago

with the dinosaurs, even.

Compared to us, Eutherian mammals on the right over here,

who on the timeline of evolution of life on Earth

pretty much climbed out of trees like yesterday.

So it's not surprising that a bird's ancient bipedal design

would actually help our current bipedal bodies.

We have an arch as a shock absorber,

while ostriches only have two toes,

with just a bone per toe,

that act as absorbers and outrigger.

These two toes stabilize the foot in running mode,

but now we must move on to the perfect-

- Ankle.

We have found broken ankles in human fossils

dating back three million years ago.

So we've been breaking our ankles for millions of years.

I don't feel so bad about my ankles anymore.

Our ankles have intervening ligaments and seven bones,

leading to numerous injuries.

So the perfectly evolved human ankles

are also coming from the ostrich.

With these ankles, we'd optimize our upright balance,

locomotion, and deal a lot better with crashes.

This is why ostrich legs have been used as models

for prosthetics for amputees,

and the Boston Dynamic Ostrich Robot

is a long-necked bird copy.

Cassie, an Agility Robotics invention,

walks with the speed somewhere between human and ostrich.

Now, let's move on to something

that has started to bother me

and is a telltale sign of old age, knees.

- Our knees are a particular type of mess.

Some evolutionary biologists argue

that we stopped evolving biologically 10,000 years ago

when we invented agriculture.

And they argue that from that point forward,

we started to evolve culturally.

But then, other evolutionary biologists think

that these drastic shifts in culture

have actually allowed for adaptive evolution,

which actually accelerated our evolution

a hundred times faster.

And that, folks, is an example of evolutionary biologists

battling it out with separate contradicting theories.

This actually happens a lot in this field of study

because we're trying to piece together information

about our human history over thousands of years.

Either way, one thing we know for sure

is that we are not running from predators,

and when it comes to eating food, we're not hunting it.

No, no, no.

I press a button on my measly little electronic device

and the food shows up at my house.

He is lazy.

I know for a fact, you probably do this too,

so do not judge me.

And for this reason, our knees need to change.

Anthropologist Matt Cartmill explains that,

"Evolution doesn't act to yield perfection,

it acts to yield function."

And that's why I have asked for

the perfect pair of Graham's knees.

Who is Graham, you ask?

Graham is a quote-unquote human

designed to survive a car crash

as part of a road safety campaign

for the transport accident commission in Australia.

Patricia Piccinini not only has a great name,

but she also used silicone and human hair

to bring us this weirdness.

Graham's knees bend in all directions

so he's able to quickly move out of the way

of oncoming traffic.

The fact that our knees only bend in one D,

also known as one direction,

is the main reason why they almost always break first.

Graham's knees being so floppy

means that they can retain their structure during a crash.

Me, after I get new knees,

♪ wash-a-widdy-widdy-bad-ba-dee-ba-doo-da-be ♪

Okay, but what about body symmetry?

- Known as the bilateral body,

our bodies have left-right symmetry.

The left side of our body is a mirror image of the right.

Non-bilaterian animals are

octopuses, jellyfish, or anemones,

but there are no non-bilaterian animals

who live on dry land.

The bilaterian body likely began on the sea floor

as bodies made for crawling over surfaces

with direction and traction made their way on land.

Since all land dwelling animals are bilaterian,

we're gonna keep that.

I'm sorry to crush your dream about having a perfect body

that is part sea anemone, but that design

is made for species that don't move.

But you, girl, you're going to be moving

in your new pair of-

- Hips.

This one is obvious.

We will be using the hips

of the perfectly evolved Shakira.

(vocalizing and upbeat dance music)

No, but for real, we do need to change

the reproductive system.

An anatomist named Alice Roberts

actually set out to design her own perfectly evolved human.

Empathizing with women giving birth to large-headed babies

and risking their health,

Alice figured humans would be better off with pouches

like those of kangaroos.

Alice 2.0 wouldn't struggle with

getting a baby out of her system.

And yes, Alice 2.0's fetus crawls out into her pouch

until it completes its development,

so her childbirth would be less painful.

Her baby would be mooching through the pouch,

so there would be no need for Alice to have breasts.

I know some straight men might be in the comments right now,

like, "But we need the titties."

But we're talking functional perfection here.

Also, we'll be taking your nipples and balls.

Male nipples are pointless.

They exist because males, females, and everything in between

come from the same genetic blueprint.

Female nipples matter.

Male nipples are pointless.

So bloop, gotta go.

As for our testes, they hang outside of us,

exposed to trauma, and no one really knows why.

Like some scientists posit

they function better in cooler air,

but elephants, anteaters, whales, sloths,

sea lions, et cetera, tons of animals do fine

with the testes inside.

So we will be tucking the ball safely inside.

- You know what?

I'm gonna start calling you the tuck.

- Speaking of sacks, onto the-

- Lungs.

Now, lungs might seem like an obvious necessity

for land dwellers, but these air pouch things

have been a part of fish long before your ancestors

left the water to live on land.

In fish, the lungs were used for buoyancy.

But even our lungs could use an update.

So with that said, coming to the stage,

your new pair of lungs evolve from a bird

that has ancestors that have been around

way longer than yours, the swan lung, ladies and gentlemen.

Our lungs are quite vulnerable to minor insults

because our delicate alveolar tissue

is responsible for both ventilation and gas exchange.

Meaning the air we breathe in meets a dead end

and has to flow in and out of the lung along the same path.

Swan's gas flow is uni directional,

which allows them to process the air entering the lung

from one side, and leave the lung through the other side.

Plus the density of tissue inside a swan's lung

is much greater than our own.

Speaking of the lungs and breasts,

they're actually two of the most common kinds of cancer,

and cancer is one of the leading causes of death.

So let's address the elephant in the room.

Or rather, the not elephant,

because they have some pretty cool-

- Genes.

And we talkin' denim.

Elephants have much lower rates of cancer,

around 5% compared to over 20% for humans.

And this is because of a cancer-fighting gene called p53,

which is a tumor suppressor.

Humans have one copy, but elephants have 20.

So we're loading this human app with some p53.

Or better yet, we should be studying the bowhead whale,

because this animal gets so big.

It lives the longest and rarely gets cancer.

Bowhead whales are so cool,

they recently found a harpoon in one

that they think is over 130 years old.

So this whale is so fricking old.

The reason they rarely get cancer

is due to a mutation that prevents their DNA

from getting damaged.

To do all of this work, we're going to be using

CRISPR-Cas9 gene editing, which is fascinating.

And I cannot wait for it in the future

to give me a dump truck ass.

- We were going to pull a cancer fighting tactic

from the naked mole rat, but...

(screaming)

Ugh.

Just kidding.

We love all animals here at ASAP Science.

Now let's encase these innards with some-

- Ribs.

Ribs are the shield for your inner organs.

So you want ribs that will absorb the most impact energy.

We're gonna go back to Graham for the stronger ribs.

Also, the chest is large and barrel-like,

and his torso is more airbag-like than armor-like.

He's got a number of sacks placed between each of his ribs,

protecting his heart and other vital organs.

And obviously I think we should be removing the lowest ribs

so that we can start to, you know, like-

- (laughs) No, moving on.

Now, we've decided on no neck at all.

I know everyone's the worst fear.

So why on Earth would we do that?

In the 1900s, accidents were

the seventh most common cause of death.

Now they're the fifth.

And our necks are super weak.

Definitely not strong enough to stop our heads

from jolting forward in an all-too-common collision.