Are San Diegans becoming as different from New Yorkers as bonobos have become, say, from chimps?
Biologist Nathan Lents was in town the other day, talking at the Central Library and on KPBS about how environment does affect evolution — but also about how we’ve had to make up for the many imperfections a stuttering evolution has left us with — as described in his book, Human Errors: A Panorama of Our Glitches, from Pointless Bones to Broken Genes.
“Differences, yes,” he told me. “But this isn’t happening on the evolutionary level. The time-frame is far too short, and we travel too much to give rise to what we call speciation.”
On the other hand, how do we define “evolution”? Maybe we are evolving into somewhat different people because of what he calls the forces of “cultural evolution.”
“People on the East Coast do tend to be different. They have more entrenched social norms; it’s crowded, there’s lots of bad weather. There’s more suspicion. I found New York intensely lonely when I first arrived. Friendships might be deeper on the east coast, but they’re more difficult to acquire. Out on the west coast, it just feels freer, people are more easygoing, but relationships can be less permanent. This is a cultural evolution that stems from the fact that populations in the West have traditionally been more spread out, more transitory, and people live outside more.”
So could we be evolving away from each other, as change speeds up?
“As far as evolution is concerned, the big change was when we evolved from being nomadic to become settled agrarians, 10-15,000 years ago. We’re still catching up with that. But change is happening faster. People are always quoting The Red Queen Hypothesis (from Lewis Carroll’s Through the Looking Glass, when The Red Queen tells Alice, ‘Now here, you see, it takes all the running you can do to keep in the same place’). We’re having to walk faster just to keep up. Conditions around us are changing all the time.”
And yet Doctor Lents says that our cultural evolution can directly affect our physical evolution, and survival. Like standing up: “We went from arboreal or tree-living creatures to land-dwelling creatures in an evolutionary blink of an eye,” he told KPBS. “And just like anything else, when you do it quickly, you don’t do it carefully. So our backs and our knees and our ankles show the signs of shoddy design.”
But to compensate, he says, we used our brains. We developed a social conscience. We took care of one another. “We have found fossils a million and a half, two million years old, of our human ancestors who lived with some crippling injury for years. There’s no way they would have survived if they didn’t have friends and family members helping them.”
So physical survival resulted from cultural evolution? Californians could be evolving differently than their East Coast cousins?
“I’m from the Midwest,” says Lents. “We may not be California-open, but somewhere in between. Certainly, people in New York notice how I’m friends with anyone. Cultural evolution!”