Armand Marie Leroi
, an evolutionary developmental biologist at Imperial College London, has written a new TV series, "What Makes Us Human," debuting Saturday (August 12) in the UK. He spoke with contributing editor Jennifer Rohn.
Q: What sparked your idea for this new documentary, an exploration of the genes that distinguish humans from the great apes?
A: While I was researching human genetic variation
for my book Mutants
, I came across a scientific paper
about the Chuas or 'rat people' of Pakistan -- a marvelous story of small-headed people living as acolytes in a shrine. It was commonly believed until just a few years ago that their small heads were caused by clamping at birth, as the Chuas can earn their minders a large amount of money begging in the streets. But it seemed more likely that their microencephaly was genetic. I didn't include this in Mutants
because nothing was known about the science at the time. But this all changed a few years ago.
Q: What happened?
A: Two genes defective in the Chua were discovered -- ASPM
. They turned out to be involved in centrosome function, and mutations reduced the number of neurons in the cerebral cortex. Skull size is dictated by brain size, so the phenotype is a small head. But what really turned me on was another paper
showing that these genes had evolved rapidly from chimps to humans, raising the possibility that our relatively big heads might be explained in part by these genes. In short, they might be crucial ingredients in the recipe for what makes us human.
Q: Is all this a new idea?
A: Yes and no. A contemporary of Darwin's, the German Carl Vogt
, collected microencephalics from freak shows, speculating that they were 'ape people'. Of course he was wrong, but he was right in intuiting that microencephalics could tell us something about human evolution. Taken together with some more new data, about the role of FOXP2
in language, and the publication of the complete genome of the chimp, I knew there was a great television program to be made. People have sought answers to the question 'what makes us human' ever since Aristotle, but now the philosophers can go home: Science has the solution.
Q: Was Channel 4 easily convinced?
A: The television show
we made of Mutants
last year was very successful, but it still took 18 months to convince the channel. And then we clashed over content. Commissioning editors don't read scientific journals: They read the Times
. They kept wanting to introduce all sorts of irrelevant science, such as sheep having emotions. At one point they even tried to persuade me to get into an MRI with an actual sheep, during which they'd show us photographs of attractive women or sheep and compare our brains' responses! The producers are always worrying about how to entice people in.
Q: Did you lose any of these battles?
A: Yes. I had to agree to interview Alex, the world's cleverest parrot -- now that was a little bit freaky. Though not strictly relevant, I grudgingly admit that it made good television.
Q: Tell us a bit about the filming in India.
A: On my first visit to the Punjab, it was just me with a notebook, a camcorder and my guide, Jimmy -- it was only later we returned with a film crew. We drove up and down the Grand Trunk Road looking for Chuas -- it was almost exactly like being in a game park, but instead of someone yelling "Zebra!," it would be "Chua!" Enormous crowds would form as I interviewed their minders -- most Chuas are too impaired to speak much. When the crew was along, we also had a detachment of special commandos to protect us -- at a certain point the crowds would get so intense that I would need to signal the army guys for "extraction."
Q: Did you get to film all your favorite ideas?
A: Well, we wanted to get across the idea that one day, lovers might want to get one another genetically tested before committing, just like in the movie Gattaca
. The plan was to film me and a beautiful woman in a Ferrari cruising down Santa Monica Boulevard looking for a back-alley testing joint. It was axed because the budget didn't run to a Ferrari -- and also because I can't drive!
Q: All this seems a bit far away from your laboratory research
on the humble nematode worm.
A: The recipe for humanity is one the great stories of our time, and most people aren't aware of it. Besides, it at least touches on my field, evolutionary development.
Q: Did your experience with filming "Mutants" teach you anything you could bring to the current program?
A: I learned a lot about what I should do differently -- and in the end was able to apply practically none of it. TV is a big machine, and you are just a cog, even if you've written the script. The director, the editors, the producers -- they all have their own artistic agendas and they know a lot more about making films than you do. It's a process of collaboration, and though sometimes things get fraught, it ultimately does work. But I do think it's important to have an actual scientist at the helm of shows like this, someone to be accountable for the science. TV wants to tell its own story, whether it's true or not. They have to be kept in check at all times.
Q: Any plans for the next project?
A: I want to write a book on Aristotle's science, on the natural world and its diversity. Aristotle is infinite: Learning his science is like learning an entire alternative universe, of a truly weird kind, and I am in continual awe of him. Because of Mutants
, which was rather dark and full of deformity and pathology, people assume I am dark and depraved myself. The current series might confirm this appetite in some people's eyes. Intellectually, human mutants have been extraordinarily illuminating, telling us how we are built and how we evolved. But as fascinating as it is ... it's time for a change. I want to go down to a beach on the island of Lesvos, drink ouzo, and watch the fish.
Armand Marie Leroi
is a Reader of Evolution and Development
at Imperial College London; he spoke to Jennifer Rohn at his home in London. "What Makes Us Human" airs in two parts, on August 12 and 29 at 8 PM on Channel 4 in the UK. Later this year, "Mutants" and "What Makes Us Human" will be packaged as a 5-part series and aired on the Discovery Channel in the United States.
Links within this article:
Armand Marie Leroi
A. Leroi, "On human diversity", The Scientist
, 24 October 2005.
A. Leroi, Mutants
, November 6, 2003.
M. Miles and D. Beer, "Pakistan's microcephalic chuas of Shah Daulah: cursed, clamped or cherished?" Hist Psychiatry
, December 1996.
J. Bond et al., "ASPM is a major determinant of cerebral cortical size," Nature Genetics
, October 2002.
A. Jackson et al., "Identification of microcephalin, a protein implicated in determining the size of the human brain," American Journal of Human Genetics
, July 2002.
P.D. Evans et al., "Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans," Science
, September 2005.
M. Torkar, "Molecular evolution of language," The Scientist
, August 15. 2002.
, the TV program
A. Leroi's research webpage
E. Lozano et al., "Regulation of growth by ploidy in Caenorhabditis elegans
," Current Biology
, March 2006.
R.B. Azevedo et al., "The simplicity of metazoan cell lineages," Nature
, January 2005.