Genetic and cellular bases of cerebral cortex evolution in primates

The lecture addresses the question of the place of humans in the history of animal species and, in particular, their kinship with other primates. For any Darwinian, sapiens is the result of evolution without finality, and we are therefore related to apes, particularly the two species Pan troglodytes (chimpanzees) and Pan paniscus (bonobos). Ideological considerations are very much in evidence when it comes to this subject, with some making humans out to be a species completely apart, even divine, and others repeating over and over that chimpanzees, the term used to encompass both Pan species, are so close to us that they should be considered human. The aim is to provide the facts that will enable us to appreciate both what brings us closer and what separates us from our cousins. As we shall see, our knowledge is still patchy and, as always in science, there is no absolute truth or, in this case, any measure that could claim to be accurate of this distance between species. To take a very simple example, even if we know that the common ancestor between the Pan species and our own lived between 6 and 8 million years ago, this says nothing about biological time, which is measured partly by the number of mutations that have accumulated along the two lineages, and partly by the nature of the mutated sites. In short, physical time and biological time do not cover the same realities. This year, and no doubt next, will therefore be devoted to studying the genetic, anatomical and cultural specificities of sapiens compared with those of the other great primates.