“Was the appearance of intelligent life an evolutionary fluke, or was it inevitable? This was one of the central themes in Stephen Jay Gould’s book, Wonderful Life: The Burgess Shale and the Nature of History (1989). If we re-played the tape of evolution, so to speak, would Homo sapiens – or something like it – arise once again, or was humanity’s emergence contingent on a highly improbable set of circumstances?”
“Evolution, we’re told, does not have a ‘direction’, and biologists balk at any mention of ‘progress’. (The most despised image of all is the ubiquitous monkey-to-man diagram found in older textbooks – and in newer ones too, if only because the authors feel the need to denounce it.) And yet, when we look at the fossil record, we do, in fact, see, on average, a gradual increase in complexity.”
“Tattersall and many others have suggested that symbolic thought and complex language gave Homo sapiens the edge, but there were physiological requirements that had to be met before the gabfest could begin. The larynx of most primates sits higher up in the throat. Only when it moved lower in the throat could our larynx produce the wide range of sounds associated with human language. Speaking also requires intricate co‑ordination of vocal cords, lips, tongue and mouth. That co‑ordination is likely facilitated by two specific regions of the left cerebral cortex, which probably took their modern form only within the last 2 million years.”
“Language isn’t only a matter of physiology. It likely evolved alongside increasingly complex social behaviour, made possible through enhanced cognitive powers, including the development of what psychologists call ‘theory of mind’ – the ability to discern that others have thoughts and intentions of their own. Equally crucial was the ability to think about objects and events that are not immediately before our eyes. We could remember the past. We could envision the future – and plan for it. We had created a brand-new world within the mind, but the pay‑off was in the real, physical world, with big game animals succumbing not to our muscle power – which was puny – but to our brainpower.”
“Language almost certainly evolved hand in hand with improving technology. If our ancestors could imagine tracking and killing a mammoth, they could also picture the kinds of stone tools that would make the job easier – both the initial slaughter and the later dismembering. And, crucially, once a tool was invented, that knowledge could be passed on, not only by showing but also by telling. ‘Here’s how you sharpen an axe…’”
“By now, of course, we’re discussing not only biological evolution, but also cultural evolution. In cultural matters, the p-word is even more despised than in biology – but it is harder to ignore. Cultural innovation seems to show directionality. Once you invent a spear, or an arrow, or a plough, you don’t un-invent it.”
“‘In technology, you really can see trends through time,’ Chazan says. ‘Things change in a directional fashion, and they do so because of the internal logic of how technology works.’”
“But perhaps the evolution of intelligent primates was itself a fluke. Intelligence doesn’t seem to be a ‘good idea’ that evolution produces over and over again, at least not the way the eye is. The late evolutionary biologist Ernst Mayr once pointed out that of the (approximately) 30 known phyla of animals, intelligence evolved only once (in the chordates) – and within the thousands of subdivisions of chordates, high intelligence is found only in primates, ‘and even there only in one small subdivision’, as Mayr put it. Mayr was willing to grant the possibility of a lesser degree of intelligence to cephalopods, and today some researchers would add dolphins and corvids to the list – but he’s right to cast our linguistic, symbol-using species as an oddity.”
“Complex life is still in its youth, relative to the age of the Universe; perhaps our planet’s future will contain intelligences superior to our own, possibly – but not necessarily – our descendants. Maybe intelligent life is inevitable, and we’re merely the first to the party.”