Free Wired for Culture: Origins of the Human Social Mind by Mark Pagel

unable to make boats to carry them there.
    CUMULATIVE ADAPTATION AND
CULTURAL SURVIVAL VEHICLES
    THE NEANDERTHALS’ plight reminds us that each of the many biological species on Earth exploits its particular environment, but for the most part it is only that environment that it can occupy. This is because biological species are vehicles built by sets of genes that have evolved together over millions of years to be good at solving the problems posed by a particular environment. For instance, woolly musk oxen are the product of a coalition of genes that natural selection has roped together to produce a vehicle suited to surviving the cold temperatures of Siberia. A different coalition of genes gives rise to camels, a vehicle good at surviving even the scorching deserts of the Sahara; monkeys are vehicles adapted to climbing trees; and the coalitions of genes we call penguins produce a fishlike bird vehicle that can survive the Southern oceans. A camel would make a poor musk ox and a penguin a poor monkey. A cross between a musk ox and a camel—were one possible—probably wouldn’t be much good at being either a camel or a musk ox.
    The lesson we learn from this is that there are no real shape-shifters in nature, nor anything like children’s Transformer toys that can change what they are. Being limited to what their coalitions of genes evolved to do, no one species can do everything. That was, of course, until humans came along and rewrote all the rules that had held for billions of years of biological evolution. Here was a single biological species using just a single coalition of genes that was nevertheless able to adopt different guises and forms in different places. In one place we could be like a heron able to pull fish from the sea, in another like a lion able to bring down large prey, in another like a camel able to survive in the desert, and in yet another we could float on the water like a duck or a seagull. Our cultural survival vehicles were built not from coalitions of genes but from coalitions of ideas roped together by cultural evolution. This meant that for the first time a single species was able to spread out and occupy every corner of the world. Where all those species that had gone before us were confined to the particular genetic corner their genes adapted them to, humans had acquired the ability to transform the environment to suit them, by making shelters, or clothing, and working out how to exploit its resources.
    It was social learning that made our shape-shifting possible because social learning is to ideas what natural selection is to genes. Both are ways of picking out good solutions from a sea of variety. Natural selection builds complex adaptations like eyes and brains from the successive accumulation over millions of years of many small genetic changes, each one of which improves on its previous form. Equally, social learning builds complex societies by a process of cumulative cultural adaptation as people select the best from among a range of options, improve on them, or blend them with others—what Matt Ridley in his book The Rational Optimist calls “ideas having sex.” And so our knowledge, ideas, technologies, and skills accumulate and build increasingly complex objects. When someone noticed that a club could be combined with a hand ax the first hafted ax was born. When someone tied a vine to the ends of a bent stick, the first bow was born and you can be sure the first arrow soon followed.
    The analogy with genetical evolution is deeper than mere words: just as genetical evolution brings together the sets of genes that produce a successful biological species or vehicle for a particular environment, cultural evolution brings together the sets of ideas, technologies, dispositions, beliefs, and skills that over the millennia have produced successful societies, good at competing with others like them, and well adapted culturally to their particular locale. These are our cultural survival