but what if we saw it as the evolution of woman?

A new book argues for a better# understanding of our beginnings,# with critical implications for our present.

Jeffrey Brown explains.

And it's for# our arts and culture s JEFFREY BROWN: Where do we come from and how did# we evolve into the beings and bodies we are today?## It's a story that continues to fascinate at the# American Museum of Natural History in New York.

Human origins.

CAT BOHANNON, Au JEFFREY BROWN: Whe child and now with a call for a new# CA T BOHANNON: We have a lot of stories about# the evolution of mammals.

We especially have## a lot of stories about the evolution# of humanity and its possible past.

But, weirdly, in so many of these stories,## the female is at best a side character.# You know what I in many different disciplines, whether# it's anthropology or in biology,## we're putting that female back in the picture.# And that actually changes how we tell JEFFREY BROWN: Bohannon tells the story in "Eve:## How the Female Body Drove 200# Million Years of Human In fact, with personal whimsy as well as# scientific data, she writes of many Eves,## starting with a creature she nicknames# Morgie, perhaps the first ever breast-feeder.

CAT BOHANNON: It's delightful that the reason# someone like me might have breasts is because## there is this little weaselly creature 200# million years ago living under the lite feet of dinosaurs and she starts lactating.# And that's why, right?

So that's just fun.

JEFFREY BROWN: And she gives# us other Eves who bring tools,## language and a whole lot more into the# tale of the human spec CAT BOHANNON: It's really rewarding to# remember how deeply ancient these things are,## that the body is in many ways a unit of# time, right, with different things that## arrive at different points in time, that# this human brain is incredibly recent,## right, and that my digestive# system is incredibly ancient.

These Eves are meant to give us a way# into where these features of our bodies## might have come from and how that story# still shapes how we live in them today.

JEFFREY BROWN: For Bohannon, whose Ph.D. research## was in cognitive psychology and# lite an example of how hominins and early humans# learned to problem-solve, is in childbirth.

You say we're one of the# worst.

We are terrible at it.

CAT BOHANNON: Oh, yes.

Yes.

JEFFRE CAT BOHANNON: Absolutely.

And we do# that by having behavioral work which is that deep human story.

It's kind# of what we're always doi finding behavioral work-arounds# for the limitations of our body.

JEFFREY BROWN: She took us a long way back.

CAT BOHANNON: How you doing,# Luce?

How's it han JEFFREY BROWN: To Lucy, the version# of her on disp are actually casts.

The actual Lucy of# the species Australopithecus afarensis## was discovered in present day Ethiopia in 1967.

Bohannon's focus, Lucy's pelvis.

CAT BOHANNON: The pelvic opening has narrowed,## which is part of what enables us to# be up here, And some really, really good scientists# have determined problem as we do.

She had the# obstetric dilemma.

She had big## babies and had a hard time getting# out of, well, a small pelvic opening.

JEFFREY BROWN: Right, which a# lot of women will relate to.

CAT BOHANNON: Yes, I did that twice.

I'm good.

Yes.

So, but the thing is that means that story,# th million years ago.

And the current theory is# that actually Lucy probably had a midwife.

JEFFREY BROWN: Lucy had a midwife?

CAT BOHANNON: Lu chimpy.

But she had a midwife, because# she had difficult births that needed help,## and in that moment of vulnerability,# to get them out.

Yes.

Yes, yes, yes.

And that's a big part of our success story,# which we don't normally talk about, but yes.

JEFFREY BROWN: Bohannon loves that famous# first scene of Stanley Kubrick's "2001:## A Space Odyssey."

But she wants# us to focus less on conflict,## more on gynecology, and how a focus# on evolution of the female body can## change how we think of the development# of other traits, such as language.

CAT BOHANNON: We assume there are these# grand moments where language arrives,## usually about hunting,# shouting directions across... JEFFREY BROWN: Yes, of course.

Isn't# that the sta CAT BOHANNON: It's a common story.

JEFFREY BROWN: OK. CAT BOHANNON: It's a common story.

all of these mixed-sex members of a group.

And# when you look at the evolution of language in## terms of its developmental path, it becomes# a childhood story very quickly.

And, frankly,## most of the time that's happening with the# mother, in part because breast-feeding.

This is when -- you're connected, literally# connected, many hours a day to a face which## is communicating with you at those# critical moments of brain development.

JEFFREY BROWN: Bohannon's book, which# synthesizes the work of hundreds of# scientists, many of them women,# raises numerous such examples.

But it also raises critical implications# for women's health today and addresses## the so-called male norm that has# traditionally guided medical science.

CAT BOHANNON: That, for a very long time# in biology and in biomedical research,## we're mostly studying male subjects.# That's how we control for estrus,## the messiness of that hormonal cycle, was just# taking them literally out of the equation.

And we're only just starting to finally# rectify that.

This is kind of a paradigm shift,## kind of a sea change.

And we don't# entirely know what biological sex## differences are going to deeply matter,# yet we will know the more we study it.

JEFFREY BROWN: We still don't know?

CAT BOHANNON: Absolutely not, world are doing that work right now,# which is why this book can even JE FFREY BROWN: She points to the growing# awareness of different responses by men and## women to opioids, for example, and the need for# better guidelines to dist CAT BOHANNON: Because we live in the bodies# we do that have this deep evolutionary time,## our health is affected by how# well we understand that history.

Our medicine is shaped by how well we're able to# incorporate better knowledge about literally what## these things are.

And what we are is made of where# we came from, because that's how evolution works.

JEFFREY BROWN: Deep time down to the present# day in a still-developing story of evolution.

For the "PBS NewsHour," I'm Jeffrey Brown at the# American Museum of Natural History in New York.