Snakes have captured the human imagination ever since Judeo-Christian mythology blamed them for malevolently bestowing knowledge upon us – it was basically all downhill from there. But in scientific terms, where did they come from? Was the earliest snake perhaps an overly ambitious eel that decided to check things out topside? According to a new analysis by researchers at Yale university, no – ancestral snakes likely lived in forests and, even in ancient times, were losing what they had left of their legs.
“Our analyses suggest that the most recent common ancestor of all living snakes would have already lost its forelimbs, but would still have had tiny hind limbs, with complete ankles and toes. It would have first evolved on land, instead of in the sea,” said co-author Daniel Field, a Yale Ph.D. candidate. “Both of those insights resolve longstanding debates on the origin of snakes.”
It turns out that the common ancestor of all modern snakes behaved similarly to the way they do today: It was likely nocturnal and preferred the warmth of the southern hemisphere. It would have relied on stealth to hunt relatively large prey and curiously, they weren’t constrictors, like modern pythons, anacondas or boas – they used needle-like teeth to hook and swallow prey whole and alive. A grisly way to go, to be sure. They would have come to be about 128 million years ago.
As for why humans were obsessed with snakes such that they made it into our religious origin stories, the researchers say our fascination with (and fear of) them is practically programmed into our brains.
“Primate brains, including those of humans, are hard-wired to attend to serpents, and with good reason,” said Jacques Gauthier, senior author of the study, a Yale professor of geology and geophysics, and curator of fossil vertebrates at the Yale Peabody Museum of Natural History. “Our natural and adaptive attention to snakes makes the question of their evolutionary origin especially intriguing.”
Which is odd, if you think about it – adult humans are too large for most constricting snakes to even consider eating, to say nothing of our size compared to deadly venomous snakes. It’s possible that when relatively few species can kill humans without warning or reason (and often without even being seen), it made sense to be vary weary of the slithery reptiles.