Origins of a Dynamic Culture
More distillations from the sayings of professor Harari, in his Coursera Course on The History of Humankind.
Of all the creatures on Earth, a significant fraction are social, but only a few of them can cooperate on large scale. Most of them are Hymenoptera. Especially ants. Ants cooperate on a very large scale, occupy some of the most profitable spots in the ecosphere, and can do some fairly fancy communication. They don't, however, have anything that could be called culture. Information transferred from generation to generation is almost certainly purely genetic.
Our somewhat large-brained (400 cc) fellow great apes cooperate on a very small scale, and even have a few elements of culture that can be transmitted generation to generation, but not much. Most aspects of their behavior are dictated by genetics and environment. The longest lasting species of our genus Homo, the pretty large-brained Homo erectus (1000cc), made some stone tools, and at least some knowledge of that tool making was probably transmitted culturally, but they couldn't cooperate in large groups and their culture was very static. They made the same tools 100,000 years ago that they made 1.5 million years ago. Even the Neandertal, with brains (1500 cc)larger than our own (1350 cc) don't seem to have been able to cooperate in large groups.
That seems to have been the pattern for our own species for the first 65-75% of its existence. That changed abruptly about 70,000 years ago. After that, change came from largely from culture rather than biology. Suddenly (in evolutionary time) we could cooperate in large groups, started inventing new technologies at a brisk pace, created art, carried out trade over long distances, and suddenly started crushing everything in our path.
One extremely promising candidate for origins of our sudden cultural dynamism may have been advances in our linguistic capabilities. Language that allows us to create stories and narratives facilitates communication among persons and transmission of knowledge other than by imitation. It seems likely that whatever language our fellow members of genus Homo had, it lacked some or much of the expressive power of our own.
Could that language development itself have been a purely cultural phenomenon? It seems unlikely. Today, at any rate, the whole infrastructure of language is biologically wired in us. Our children learn whatever language they are exposed to quickly and naturally. If large groups of them are not exposed to a single language, they invent their own, and the invented languages are full-featured, not some stripped down versions.
What seems more likely is that there was a gradual accumulation of genetic and cultural changes which didn't reach a critical mass until 70,000 years ago, at which point people, language and culture quite abruptly became modern.
Of course we don't really know.