That our society continues to rehash the same tired arguments against evolution more than thirty years after this episode first aired may have come to no surprise to Sagan. I personally find it the source of great sadness that one of the most astonishing discoveries in human history – the evolution of species through the means of natural selection – still faces such resistance. Not just because it’s a slap in the face to the progress inherent of the modern era, but because its denial means rejecting our place within all of known life. We are part of a dark and beautiful story of four billion years of survival against the odds, an unbroken chain that unites every living thing. It’s deeply compelling and strange and hopeful. And to deny that unity serves to isolate us all the more.

In what I imagine is an attempt to stamp out anti-evolutionary dissent. Sagan takes a stronger-than-usual tone in this episode. His language is less forgiving and more concrete, stating that “evolution is not a theory, it’s a fact. It really happened.” Which is, of course, true, but unfortunately portrays him as the authoritative scientist in an episode that, more than most, glosses over major unknowns and important caveats of the time in the name of impressing upon its viewers the validity of evolution.

I watched this episode with a few scientist friends of mine. One of them, who had never seen Cosmos before, felt unsettled afterwards.

“He presents to us a story of events without focusing on the uncertainties of the scientific reality,” they said (I’m paraphrasing), “It’s just replacing one authority figure for another. It’s not teaching people how to think critically.”

I hadn’t really thought about this before, but it’s an important point. Is the responsibility of the show to teach us how to think critically? Or is it to teach us facts about the cosmos? If it’s just teaching us facts, does its reliance on an authoritative narrator undermine the value of those facts? What’s to prevent a usurper – a faux-authority – from doing the same thing? How can we decide the veracity of either if we are meant to passively accept Sagan’s statements from his authoritative position as a Ph.D. scientist?

Generally, I think Sagan does a pretty good job of mentioning when he’s speculating, or when science doesn’t yet fully understand a topic, or that whatever he’s saying is only the best-understanding at the time. But it’s true, he’s not explicitly teaching his viewers how to think critically, though I’d argue that he provides us with more than enough examples of people who do. But this episode, since it’s dealing with a topic so often maliciously misrepresented, hammers home the fundamental correctness of evolution (note how Sagan walks us through the concept at least three times throughout the episode). We don’t always have the luxury of dealing in grey-areas or caveats when the larger concept itself is so poorly understood by the majority of the viewing audience.

And maybe, by presenting us with so many facts about evolution and other ideas throughout the series, people may use that as a starting point to increased skepticism and critical thinking. I feel that, a show meant for a large audience with perhaps a passing familiarity with science, that Cosmos needed to focus on facts first.

So Sagan does exploit his authority in this episode, but it’s a practical conceit. He happens to be correct, for the most part, though the show does contain a major error in one of its segments, as we’ll see.

The episode opens in the great expanse of space. Sagan and the SotI takes us on a tour through the great globs of organic matter that drift between the stars (a nice thematic call-back to our first episode). Not only do we learn that we are connected to all living things, but our very building blocks of our molecular chemistry can be found scattered throughout the galaxy. We are deeply connected to the cosmos itself, our chemistry binds us to the immensity in a way no human being had ever imagined before the modern era.

These menacing interstellar inkblots contain “the stuff of life,” and Sagan speculates that rudimentary life may be common throughout the cosmos, though perhaps intelligent life is only a small fraction of it. Some of you may recognize this concept as the Rare Earth hypothesis, which depressingly and effectively argues that life beyond basic microbes may be extremely rare, requiring far too many unlikely events to make intelligent life an expected outcome of evolution. While this does help explain the Fermi Paradox (the fact that the universe is so big and old yet we have found no signs of other intelligent life) it feels far too anthropocentric to me, relying entirely on our current, singular understanding of biology that, as Sagan points out, is extremely provincial. Our history is littered with discarded impossibilities based on our own desire to be unique and central to the functioning of the universe.

As in the first episode, we arrive back home at Earth – brilliantly blue in a sea of black – as we begin to approach our biology. And though our biologists are severely limited based on the singular basis of DNA behind all known life, we see such a diversity of forms most complex and most beautiful that I imagine they keep busy. But imagine, as Sagan does, one single alternative example of life. How revolutionary that would be.

I’ll have a lot more to say about the compelling nature the question of the existence of alien life and its centrality to the series as a whole in my Episode 12 recap, but suffice to say I can’t overstate the importance of Sagan’s willingness to speculate. It connects us to him as narrator, simultaneously validating our wandering thoughts and sharing in our excitement. It’s delightful, really.

As we arrive at Earth, we jump back in time to 12th-century Japan and the story of the Heike crab. These crab have an unusual carapace which looks not unlike the face of a scowling samurai. Sagan confidently declares that this is due to their artificial selection by centuries of Japanese fishermen honoring the legend of a vanquished clan of warriors. Crabs that had a small mutation in their genes that caused their shell to have a semblance to a human face would be thrown back to the waters. Those without that mutation would be eaten. Over the centuries, this artificial selection refined the shells of the crab to be distinctly human, all due to a unique historical legend.