Evolution has never been more popular than it is now, and rightly so. Darwin’s legacy is one of the most potent ideas ever. Not only is it a crushingly powerful explanation of life, but its core mechanisms of reproduction, variation, and selection apply to all sorts of other domains. Technology, memes, and capitalism are common examples, but they’re just the beginning.
We can take it a bit overboard, though, especially when we start navel gazing and wonder how humans are evolving. We don’t yet have square, keyboard-friendly fingers, or ears with perfect earbud-shaped holes, but are we evolving shorter attention spans, more Asperger’s syndrome, or faster video game twitch reflexes?
No, we’re not. First, evolution takes a long time: thousands, even millions of generations to see real changes in a phenotype. All of recorded history is still just a couple hundred generations old. Technology and other changes in modern life affect us profoundly on the nurture side, but not so much (yet) on the nature side.
We’ve also intercepted two of evolution’s three legs, selection and reproduction, and thrown them wildly off course. Modern medicine may not be perfect, but it does ensure that most babies survive into their adult, childbearing years, regardless of their innate health or fitness. That throws selection out the window.
As for reproduction, you probably know at least a few happy couples who have chosen not to have children. Widespread birth control had a profound, unprecedented effect on our species when it unshackled sex from procreation. It also had an important side effect: unlike animals, the fittest people no longer had the most or strongest children.
(Another surprising side effect is that we’re all having too few children. The developed world has plummeted far below the replacement rate, and it’s only getting worse. Labor markets have shrunk across the world, especially in developed regions like the EU and Japan where economies are already stagnating. So much for Malthus and Ehrlich.)
We may have disintermediated selection and reproduction, but variation is still intact. IVF, surrogates, and adoption haven’t changed the fact that sperm and egg still mix DNA randomly to make a baby, and they still do it with good old RNA transcription, an amazingly good natural process that nevertheless lets the occasional mutation slip through.
Sure, epigenetics is all the rage these days, and it incorporates the environment, and it’s even hereditary, but it still just turns our existing genes on and off. Epigenetics still doesn’t provide any evidence for Lamarckian style inheritance of skills you acquire during your lifetime, and no one expects it ever will.
It’s definitely fun (slash worrying) to think about how we’re adapting to technology and modern life. Responses range from techno-utopianism to “kids these days, get off my lawn!” The human brain is amazingly plastic, especially when we’re young, so yes, iPads and Facebook and video chat leave their mark on us. That’s not evolution though, and it’s silly to pretend it is, if not downright intellectually dishonest. Evolution isn’t that good, or that fast, and it doesn’t matter since we’ve pulled the plug on it anyway.
The real conclusion isn’t that we’re evolving, but that all sorts of other things are, in entirely new environments. Startups compete, multiply, and often exit or fold in just a few years. Their products have even shorter lifespans. Superbugs evolve resistence to antibiotics by cranking out hundreds or even thousands of generations in under a year. Internet memes spread like wildfire overnight. Culture, politics, art, and many other parts of the modern world evolve at a speed we can appreciate, leaving artifacts we can see and touch.
If you want to see evolution in action, that’s where it’s at. Forget the pseudoscience; humans aren’t evolving right now, and that’s ok. There’s so much of it going on everywhere else!