I recently finished Before The Dawn by Nicholas Wade, a book about the evolution of the human race which I happily recommend.
Studying the history of human development has typically drawn on things buried in the dirt: paleontological/biological artifacts like the fossilized bones in Olduvai Gorge for one example, and archaeological/cultural artifacts like the ruins of Nineveh and Route 66 for another. The problem is that stuff comes out of the dirt… very… slowly, putting a real damper on our ability to learn quickly. Wade’s book focuses on a new kind of ore, which is the living information buried in our genes and in our languages. Genetic data in particular is a fabulous gold mine for those trying to work out our past.
Surprisingly, it’s not just human DNA that’s useful. It’s possible, for instance, to work out approximately when humans started wearing clothes by genetically dating when human lice split into head-dwelling species and clothes-dwelling species. Clever! And we’re starting to get a remarkably accurate story of how humans migrated out of Africa and populated the world.
Happily, Wade is not the least bit gun-shy in talking about evidence of evolution currently under way in humans. There is good evidence that our behavior is pacifying with remarkable speed owing to the powerful adaptive advantages of law-abiding socialization. But just as evolution selects for the important, so it forgets the unimportant. Sadly, we’re shedding our sense of smell with alarming speed. A good nose makes your dinner taste good, but it’s not especially selected for. Rats can synthesize their own vitamin C, but humans lost that ability long ago. As long as you take your Flintstones vitamins, who needs to synthesize the stuff?
Obviously this all leads to the big question: what’s next? Wade doesn’t speculate much, but I will. It seems clear that modern medicine is going to allow our onboard health maintenance to get weaker and weaker. Just to pick one example: accurate, timely vaccines mean our native robustness won’t be put to the test, and that which isn’t selected for drops away. This may appear disturbing, but really what we’re doing is evolving an outboard immune system. We are offloading many heretofore intrinsic biological tasks to the next level of abstraction: the community.
This includes the outboard brain. Networks are the nervous systems for the big bug, the communal organism that we are becoming. Just as individual cells had to make some dramatic accommodations in order to form multicellular organisms, our native behaviors will be ever more conducive to hive action. We’ll sure have to get rid of all the errant terrorism genes before we can manage long term space colonies. It only takes one crazy person to wipe out a space village.