We’re in week two of the Cosmos reboot, and as in the original 1980 series, this episode is all about evolution. Where Carl Sagan began his second episode with a Cosmic view, wondering whether life might be all over the universe, Neil deGrasse Tyson takes us straight to ground level: “This is a story about you, me and your dog.” The selective development of dogs from wolves — beginning with the wolves that tolerated humans enough to scavenge from their camps, humans bred the wolves that were more docile — is an easy illustration of huge changes in a species through artificial selection. Tyson calls it “survival of the friendliest,” and it’s a viewer-friendly move: by emphasizing the deliberate selection of specific traits, the show sets up the larger topic of natural selection with a friendly, tail-wagging example. Tyson gets the chance to explain that “cuteness became a selective advantage — the more adorable you were, the better chance you had to live and pass on your genes to another generation.” It’s a smart choice, since doggies are loveable, and a conscious contrast to the “red in tooth and claw” version of evolution that people usually think of. There’s another cartoon — ahem, animated segment — illustrating how early dogs and humans got along, and how humans shaped the doggie genome to range from critters that still look sort of wolfy to little ankle-manglers, all of them members of the species canis lupus familiaris.
From dogs, we move on to the genetic machinery of evolution, and for the sake of fancy computer graphics we ride along for a look at sparkly gold DNA molecules inside a polar bear’s egg cell. It’s pretty much the same discussion of how DNA works as Sagan had in 1980, but with far prettier graphics; it gets at the same point, though: mutations, occasional missteps in the replication of DNA, are usually meaningless, or harmful, but every once in a rare while, they result in a change — like white fur on a brown arctic bear — that provides a survival advantage in a particular habitat. And over vast stretches of time, those changes result in new species. You get a pretty good sense of how basic the aims of Cosmos are when Tyson reminds us that a single bear doesn’t evolve — populations of bears do, over generations. But that’s not a flaw, really; there’s so much misunderstanding of evolution out there that the show really does have to counter the people who say they won’t believe evolution is true until they see a bear turn into a bird (and that’s OK — as Tyson is fond of saying, science is real even if you decide not to believe it).
While it’s clear that the producers are very much aware of the pushback against any mention of evolution, enough so that they acknowledge that the idea of being related to chimps may cause a “twinge of discomfort” (and not even asking the chimps how they feel), Cosmos is unapologetic about evolution’s centrality to science, and notes that DNA is DNA, and humans, trees, sharks, and butterflies all have some of the same DNA instructions for metabolizing sugars — and no embarrassing poo-throwing with those examples. Not that it will mollify creationists, of course, but perhaps it’d be enough of a peace offering to allow the science to actually reach viewers who can be reached. Tyson’s optimistic suggestion that he finds the connections of all life on earth spiritually uplifting probably won’t impress any of the people busily explaining that evolution is a fiction.
The “tree of life” graphic, using an actual tree with drawings of plants and animals superimposed on it, seems way cheesier than the more conventional diagram version of such connections, but fortunately, we’re soon off to a tour of some of the nifty adaptations that life has come up with. And then, in a segment that directly talks back to a creationist/intelligent design shibboleth, Cosmos looks at how the human eye evolved. It’s easily the strongest section of the episode, looking at how random mutations benefited various early creatures — just being able to sense and react to light would be a huge advantage for single-celled organisms in the early seas. And then, once we get to the development of eyes in terrestrial creatures, Tyson points out that our eyes are actually not the best possible sensory organs for land-based critters that have to see through air, instead of water — our vision is really pretty lousy compared to the excellent underwater vision of fish whose eyes our ancestors inherited and which natural selection had to make do with. And so the human eye, rather than being a miracle, is revealed to be the elegant result of generations of adaptive jury-rigging. As Brother Cavil griped in Battlestar Galactica, why would any intelligent designer give us these ridiculous gelatinous orbs that can’t even see infrared or X-rays?
Next, we get a bit that wasn’t in Sagan’s version of Cosmos, but works pretty well — a visit to a notional museum, the “Halls of Extinction” recording the five major extinctions that wiped out huge portions of the planet’s life. Bye-bye, trilobites. Bummer about your oceans getting poisoned by hundreds of thousands of years of volcanoes in the Permian die-off. Same for the dinosaurs and that asteroid, a few hundred million years later. And then there’s that ominously empty, unnamed corridor, the unspoken reminder that we’ll be extinct at some point. (And of course, the old joke about the astronomy lecturer who’s asked by an audience member, “Did you say the Sun would die out in millions of years, or billions of years?” “Billions.” “Oh, thank goodness!”)
The last segment, a speculative visit to Saturn’s moon Titan to search for life that might inhabit its methane seas, is a bit of a letdown, and not merely because Titan houses no visiting Tralfamadorians. Where Sagan had been willing to make some wild guesses about possible forms of life that might evolve in the atmosphere of a gas giant like Jupiter — critters he called “floaters” and “sinkers,” possibly because he never vetted those the names with a panel of 9-year-old boys — Tyson won’t venture any guesses about what critters might live in methane at -180 degrees C. Instead, we get only a lot of pretty spacey seascape effects, a hint of movement in a shadow, and a quick “did you see something over there?” Meh. We want aliens, dammit, even if they’re wild guesses.
The episode ends with a “visit” to primordial Earth, and an acknowledgment that we don’t know how life originated, and then a recapitulation of the first Cosmos‘s animation of the evolution of life from single-celled organism to line drawing of a human in just 40 seconds; unfortunately, it feels kind of rushed, especially without the longer explanation that preceded it in 1980. Happily, that full segment is on the YouTubes, with Sagan’s comfortably goofy pronunciation of “primordial SOOP:”
I’m becoming convinced after just two episodes — the best way to watch Neil deGrasse Tyson’s Cosmos: A Spacetime Odyssey is to watch it alongside Sagan’s Cosmos: A Personal Voyage. This is not to say its only value is as a pointer back to the earlier production; the two shows actually work pretty nicely as bookends.
Cosmos: A Spacetime Odyssey airs on Fox 9:00 Sundays Eastern/Pacific, 8:00 Central/Mountain. Reruns Monday on National Geographic Channel 10:00 Eastern. Episode 2 online at CosmosOnTV.com