As I wrote recently, the evolutionary race is never over. So, the oft-touted claim that natural selection is over for humans, shoved aside by medicine and a lack of predators, is tempting but mistaken. That doesn’t mean in the least that natural selection is out of style: only that the selective pressures have changed.
Another common but mistaken idea is that evolution has a plan, a goal: it doesn’t. All it does is retool the materials it has to hand, to meet the demands of the environment. If you’ve ever seen a photo of a Third World bathroom where hot water is supplied with a garden hose, a kettle, a plastic jug and an extension cord: that’s kind of analogous to how evolution works. A designed system is a shiny new hot water service; evolution kludges together whatever is lying around into something that works. Sort of.
Walking upright, for instance: it has massive benefits, such as free hands and efficient travel, but some big drawbacks. Blocked sinuses, for starters: creatures who spent hundreds of millions of years evolving horizontal body shapes also evolved sinuses that drain fairly easily from that position. Standing upright buggered that up: suddenly the snot that ran off with little problem now pools in our sinuses and can make our lives a walking misery.
But that’s nothing compared to the really big problem walking upright created, in tandem with the most biggest evolutionary winner humans ever made, our big brains.
Before you ever encounter the indignities of infant mortality or the dubious charms of modern courtship on the long and winding road to passing on your genes, you must successfully navigate the microscopic roulette wheel of the prenatal chamber. It’s an abattoir of molecular ambition that claims from a third to half of all conceptions before birth. Having miraculously survived this primordial lottery, the intrepid neonate arrives at the second great tollbooth of human existence: the birth canal.
Here, the grand architectural compromise of our anatomy reveals itself in all its farcical geometry. For two million years, this structural impasse claimed no small number of maternal and infant lives. Nature, ever the slapdash renovator rather than the meticulous architect, solved this logistical nightmare by simply evicting the tenant prematurely, producing an infant that resembles an unfinished potato compared to the self-sufficient progeny of our primate cousins. Infants of other species can run away from predators within minutes of being born. Monkeys are a little slower, taking at least a few weeks. But human babies are helplessly dependent for years (sometimes as many as 30, these days).
Yet, true to form, modern humanity looked upon this biological bottleneck and decided to intervene with surgical steel.
If you’re born with a C-section, you basically cheated nature. And if you carry genes for a huge head and narrow pelvis, well, you can pass those genes down to your kids.
Naturally, medical technological wizardry has spent the past century joyfully disabling nature’s survival filters. But to imagine that the great machinery of evolution has ground to a halt is to misunderstand the subtle cruelty of the ledger of natural selection. While survival filters recede, or simply change, the mechanisms of sexual selection merely shift their theatre of operations to the new evolutionary topography.
In the animal kingdom, the division of labour regarding reproduction is stark. Males sprout antlers, tusks, and aggressive dispositions, battering one another into oblivion for the privilege of feminine favour. Yet human males present a rather less formidable armoury. Our dimorphism has flattened remarkably over the millennia and for a very distinct reason: human fathers actually stick around (or they did, until the welfare state lifted the selection pressure from deadbeat dads).
And the moment a male invests years in one family, he can’t afford to gamble on just anyone. So he gets picky too. In modern times, both sexes choose, which means both sexes get filtered.
This mutual fastidiousness has played out across the centuries in fascinating ways, shifting from the brutal, despotic polygyny of the agrarian era, where powerful patriarchs monopolized entire demographic landscapes, to the strictly enforced monogamy of Christendom, and finally to the dizzying supermarket of modern romance.
This brings us neatly to the digital epoch’s supreme contribution to the evolutionary saga: the pocket-sized luminescent oracle.
Today, more couples meet online than in any other way. And when the table is endless, being picky is free. And when being picky is free, everyone is.
The smartphone has not rewritten the fundamental biological rules; it has merely expanded the dinner party from a modest village hall to a global amphitheater of eight billion souls. When option anxiety becomes our default state of being, the filtering process grows ruthlessly efficient. In places blessed with sensible demographic record-keeping, such as the Nordic nations, the data paints a stark picture: a rising tide of unpartnered men standing entirely outside the generational ledger. And if selection now favours wastrels who sow their seeds far and wide, and the females who accommodate them, well, that’s the way the loaded genetic dice roll. Evolution possesses neither malice nor benevolence – it merely keeps score.
Evolution isn’t a force with opinions. It’s just a renovator who does bookkeeping on the side. Which gene variant becomes more common in the next generation and which gene variant becomes rarer.
Thus, we deceive ourselves if we fancy that mankind has somehow stepped off the evolutionary treadmill. The ledger is open, the ink is wet and whether we’re navigating the ancient hazards of the pelvis or the modern purgatory of the dating app, the ruthless audit of tomorrow continues apace.
