Dean Falk is always up for a fight. She has traded shots with rival anthropologists over the meaning of ancient skulls and weathered gunfire from warring nomads during fossil hunts in Ethiopia. Conflict hasn't deterred her from investigating a knotty subject for more than 30 years: the evolution of the human brain.
Falk's fascination with our mental history has led her to explore how brains keep cool, the differences between male and female cognition, and the origins of music and language. But Falk, 63, isn't stuck in the past. She uses sophisticated medical imaging technology to scan fossilized skulls and create virtual brain models called endocasts. The endocast of one particularly hot fossil — the tiny "hobbit" skull found on the Indonesian island of Flores in 2003 — landed her in the middle of a raging controversy. Scientists are still debating whether the hobbit is a human with a brain-deforming disease such as microcephaly or, as Falk believes, a new miniature species clever enough to make stone tools.
The argument won't end anytime soon, says Falk, who compared the hobbit's remains to nine microcephalic skulls and concluded their shapes don't match. Since then, she has disputed claims that the hobbit suffered from two other ailments, Laron syndrome and cretinism. "We think of it as the disease of the week," says Falk, an anthropologist at Florida State University. "We'll answer it, and then they'll come up with a new one."
In the meantime, Falk is figuring out how human language evolved from primal to poetic. The first words may have begun with baby talk, or the soothing sounds from mother to child, she suggested at the February 2008 meeting of the American Association for the Advancement of Science in Boston. Falk plans to publish a book on the subject in 2009, tentatively titled Finding Our Tongues: The Role of Women and Infants in Language Origins.
You've been caught up in a huge debate for the past three years about the hobbit skull. Some people call it the biggest controversy in anthropology today. What has that been like for you?
Great. It's been wonderful. To find a complete skeleton is very, very rare. I love studying the endocasts, which pick up the external morphology of the brain. When I was first invited to do it, I had a preconceived idea that anything that small would look like a chimp brain. And it didn't. It looked like a very fancy little rewired brain.
Your work suggests that bigger brains aren't necessarily better. Does that change the way we think about our evolution?
It does. Brains can get bigger, or they can change their wiring, or do some combination of both. What this shows is this brain is really little, but boy, is it rewired. It's got these huge convolutions. Believe it or not, that's where you do your higher thinking, on the outside part of your brain. And I think what might happen now is more fossils will be found, including possibly in museum drawers where they've been ignored for years, and who knows what other surprises are out there.
You had an experience a while ago where you found a hominid bone in a museum [in South Africa] that had just been lying around.
Yes. It was my first or second trip to Africa. I decided while I was there that to be thorough, I should look through all the boxes of scraps in the back storage room. And in one marked "Unidentified Monkeys," I found a fragment of an endocast that was too big to be monkey. It was hominid. And the museum director said, go ahead, you can describe it. So it was very lucky.
The hobbit skull was in Jakarta, and there was quite a tussle among scientists over who got to look at it. How did you get access to it?
I was sitting at home in my study, working, and my phone rang. I answered it, and a man's voice said, "Is this Dean Falk?" I said yes. And he said, "Hi, my name's David Hamlin and I'm with the National Geographic Society." I put my name on Do-Not-Call lists and I'm about to do this [hang up], but I just listened a little more and he said, "I've been dying to call you for some months." And he started telling me about the discovery. He said in Indonesia, there's this island Flores, and Mike Morwood discovered this 3-foot-tall individual nicknamed "hobbit," and it's got a really nice skull. At one point I said, "Are you making this up?" And he laughed and said, "I assure you I'm not."
So did you fly to Jakarta?
No. I had to persuade them that we couldn't do it the old-fashioned way with calipers, that it was too important. We needed to CAT-scan a virtual endocast. You CAT-scan the skull in Jakarta, and then you send the data to St. Louis to an electronic radiation lab. In that lab, we were simultaneously filming and we also wanted to do the science, so it was this frantic trip. But as we saw the images, we got really excited. Because we realized how it was turning out.
According to one news story, the opposing researchers called your work "naughty."
Yes, because when we published our work on microcephalics, we'd included four less than fully adult individuals. We were called naughty, and other things. It became a fairly emotional, acrimonious controversy. I hope it's calmed down. We feel like we've really answered the microcephalic claim.
Are you friends with these people?
I'm civil to them. We went out and had drinks with people from the other side and chatted with them. We were civilized.
"Females may be better skilled in linguistic things, and males may be better at spatial orientation things. It works with other animals. That doesn't bother me, that kind of reasoning. And people can now do medical imaging so we can address these questions in a sophisticated way. So I get a little upset at political correctness that says we shouldn't even ask that question."
But you're probably not going to become penpals.
I don't think so.
You're written about the differences between male and female brains. What did you make of the outrage that erupted when [former] Harvard president Lawrence Summers said women might be underrepresented in the sciences because of biological differences?
That was unfortunate, that statement. Within each sex, there's a small but statistically significant correlation between brain size and intelligence, with lots of slop. But it doesn't work if you compare men to women.
So you're saying that in general, bigger brains do mean that you're smarter?
I wouldn't say that across Homo sapiens because the data don't support that men are more intelligent than women. There's data that suggests females may, on average, be better skilled in linguistic things, and males may be better at spatial orientation things. It works with other animals. That doesn't bother me, that kind of reasoning. And people can now do medical imaging so we can address these questions in a sophisticated way. So I get, if anything, a little upset at political correctness that says we shouldn't even ask that question. I'm just real interested in knowing what the data are and what it means.
You wrote a letter to Nature saying that female scientists appear to be achieving immortality.
Yeah, wasn't that fun? I kept noticing that the obituaries are always men. For quite awhile I thought someone should actually do a study on this. That's what I did, and there was an obvious bias in favor of men. So I wrote a somewhat tongue-in-cheek communication to Nature. They had some piece about what was going to happen in the future with the lack of women scientists. I said I had the solution: Just let them know that they become immortal.
You have an unusual name, and at least one newspaper article has mistaken you for a "he." Does that happen often?
It doesn't happen as often as it used to, but it still does. I corresponded with somebody, a woman, and at one point she said, I get it! You're a woman! She had said to me, thank you for being a feminist. And I realized she thought I was a man.
I understand that in your new book you're connecting motherese, or baby talk, to major steps in our human evolution. Can you tell me about that?
During hominid evolution, two things happened that opposed each other. One is that the brains increased rather steadily from three million years ago. The other is that walking on two legs became more refined. The refinement of bipedalism required that bones change, which constrained the birth canal. There was an increasing fetal head size which was being further and further restricted by a narrow birth canal. The solution to that was to totally change the development schedule. So we have infants that are born really helpless. Ape babies are pretty autonomous in that they can cling to their mothers. A chimpanzee mom can climb up into a tree using all four extremities — their baby's just like Velcro. Human babies, as any mother will tell you, don't do that. It's up to the mother to carry that baby.
And the mothers would then have to talk to these babies to soothe them?
I see that as the beginning of when motherese would have started to evolve. There's no primate other than humans where moms just ooze this baby talk continually. It's a real human thing. Hominid women would have had to use their hands to get food, and I don't think they put them down somewhere else. So I think the solution was you carry your baby as long as you can stand it, and when you want to stop, you just put it down, and that's when the vocal channel would have come under [evolutionary] selection.
So baby talk was the first step on the way to the language we speak today.
Yes. I wouldn't call it language, but I think it planted the seeds for the later emergence of language. The thing about motherese is it's musical. It helps infants parse speech that they're hearing, where one word begins or a syllable begins and another one ends.
But how do you go back in time and see if that's what happened with the earliest humans?
You can't, unless you get a time machine. So you look at the fossils. You look at different people and languages and how they learn them. You look at lullabies — that's really important. And then look at cultural transmission and how it's done, particularly higher primates. You look at genetic stuff and brain stuff. And you try to tie all that together.
Do you think you'll be able to?
That was what I did in the book. How it will be received remains to be seen. Academics, particularly linguists, can be hostile to the idea.
Well, you're no stranger to controversy.
True.
Roberta Kwok, a graduate student in the Science Communication Program at UC Santa Cruz, earned a B.S. in biological sciences from Stanford University and an M.F.A. in creative writing from Indiana University. She has worked as a reporting intern at the Salinas Californian, the SETI Institute's radio program "Are We Alone?", and ScienceNOW. Roberta will travel to Idaho this summer on a science writing fellowship from the Idaho National Laboratory.
© 2008 Roberta Kwok
