NOVA: Becoming Human

OK, I’m going to live-blog this show. I’ve been looking forward to it for a while – I loved the old NOVA series with Don Johanson and have often showed it in classes but I had to stop several years ago because it’s getting out of date. These are great overview-type programs, unlike the more special-purpose one-topic shows.

The producers gave me the opportunity to review the program’s script a few months ago (that’s explains the acknowledgement at the end), so I’m not expecting any unpleasant surprises.

The pre-credits opening: Naked people smiling. Naked chimps grooming…

7:01: “What set us on the path to humanity? The questions are huge, but at last, there are answers…”

“For millions of years, many human-like species coexisted on our planet, until one day, there was only us.”

7:03: “Apes that had walked on four legs stood up and walked on two.” We see apish CGI hominins. Then, to the Sahara to see Toumaï. Michel Brunet is describing the skull.

“We, Homo sapiens, are the first ever to be alone.”

7:06: To the Afar, explaining the Rift Valley and its erosive contexts. The Insta-Zoom effect across the desert is actually kind of cool. We see Zeresenay Alemseged driving an SUV, then walking in badlands with scattered bones. Nice photographs of the Dikika skull in context.

7:09: Zooming backward into a timeline, as if the years are sucking us back, the program explains the timespan of human evolution as a series of doublings backward in time.

7:10: Alemseged is in the National Museum of Ethiopia, preparing the skull. It’s a nice video treatment, shoing the slow preparing with dental drill. The long shots of the postcranial elements are very illustrative – this is a good demonstration of how the anatomy informs us about the developmental schedule and lifeways.

7:13: Don Johanson is explaining how he found AL 129-1. Then, he explains the difference between the chimpanzee and human pelvis. Too bad they couldn’t have included Ardipithecus; it would be interesting…. I’m really liking the fact that you have people interacting with actual casts instead of lots of CGI images. You have a much better impression of the scale

7:15: Now the scene moves to Kenya, this is going to be about paleoenvironments. Yannic Garcin and Daniel Melnick are describing how the now-desert landscape was once much wetter. We go back to the Afar, with Alemseged explaining the fauna that’s just eroding up out of the ground (wonder how set up that scene was…).

7:18: Bipedalism. It’s like Saturday Night Fevur. Brian Richmond appears to explain theories about why bipedality was adaptive. This is all accompanied by contemporary dancers wiggling around. Chimpanzee-like ancestors are illustrated with video of actual chimpanzees (wonder what Lovejoy is thinking…). Dan Lieberman is talking about energy budgets. People and chimps on treadmills hooked up to oxygen meters.

7:22: Mark Stoneking explains the molecular clock. “The dates that one almost always gets are 5 to 7 million years ago for when humans and chimpanzees shared a common ancestor.”

7:24: We go to Chad. Brunet explaining why they needed to recover fossils from somewhere other than East Africa. “Everyone said ‘no’, there just aren’t any [human-like] fossils there.”

7:26: “There were no bones apart from the skull…” Er…

7:27: The skull is reconstructed with a CT scanner and then cast. Oops…the rest of the shots of casts are all taken directly from the skull, not the 3-d scan version. Nice artist’s rendering of Toumaï here.

7:30: I’d hate to be one of the dancers walking by on the screen with the voiceover, “Walking upright didn’t mean that they had big brains.”

7:33: Brain growth in Selam. Hints of a longer childhood – of course, at 330 cc, it’s almost the size of a full-grown chimpanzee. Todd Preuss is discussing the evolution of the brain, showing us actual pickled brains of human and chimpanzees. Lunate sulcus – was Selam like a human or a chimpanzee?

7:35: Ralph Holloway is describing the brain reorganization – great shot of him with his collection of endocasts. The conclusion is that the lunate sulcus was human-like.

7:37: Now we have stone tools appearing, Brian Richmond explains how we recognize tools. Unlikely they were made by Australopithecus, because they didn’t make them earlier. Skip forward to KNM-ER 1470, “the dawn of a new era, beginning around 2 million years ago.” Tools were used for meat processing. Homo habilis was small in body size, but had a much bigger brain than Australopithecus.

7:41: Viktor Deak is reconstructing Homo habilis. I like it, more apish than the usual rendering.

7:43: “Africa’s gradual drying trend was punctuated by bursts of rapid climate fluctuation.” We see Rick Potts explaining the stratigraphy of a lake alternating with desert and volcanic layers over time. The idea of “variability selection” is explained.

7:45: Analyzing diatoms in layers of rock – the species tell the alternation of shallow and deep lake levels. It’s a record of strong fluctuations. We see rapid clips of three different scientists (Potts, John Kingston, and Mark Maslin) talking about water fluxes. It’s a good way of explaining the climate instability – although they could have gone a bit further: when they mention “Lake Victoria-sized lakes appearing and disappearing”, for example, they might have pointed out that Lake Victoria itself has appeared recently.

7:48: Dust from ocean cores. Once again, it comes down to tiny sea creatures whose anatomy correlates with date.

7:50: We get a rapid montage reviewing the climate instability idea. Hmmm…I have to say that the very fast cutting of clips and louder music doesn’t really add to the credibility of the idea – it seems like something is being left out.

7:51: Rick Potts restates the variability selection argument. “Simple but revolutionary idea – human evolution is nature’s experiment with versatility…we are creatures of climate change.”

That’s the end. I think the paleoenvironment story was well done. The shots of how this science is done were very illustrative – from the field to the lab, the program showed the fine layers of sediment and careful study of microscopic creatures.

On the other hand, the show may have gone a little too far in the “climate made everything happen” direction. I don’t think the “variability selection” idea explains the origin of Homo, and while the program did briefly list alternative views about the adaptive value of bipedality, it left no doubt that African desiccation and loss of forest was the ultimate cause.

I think everything with actual fossils, dirt, or rocks was well done. In particular, we got a good view of most of the Selam skeleton, with the notable exception of the hyoid bone. These are the best available images of the specimen to date. Holloway’s descriptions of endocast evolution were well done, placed in the middle of a big table of fossil casts. I like the solidity with which the program showed the fossil record. Hopefully the next two segments will also follow this technique – much preferred over the CGI-reconstruction technique.

I will be out of the country for the next two parts of the trilogy, so I’ll have to see if I can get them online. The NOVA Evolution website has the first episode online now, so there’s some hope.