Although the brain is a very expensive organ that consumes a considerable amount of energy, there has been a steady increase in brain size during evolution. According to Robin Dunbar, the larger brain of monkeys serves to establish social relationships with a larger number of individuals and to form a larger stable social group.
evolution of humankind, brain volume increased further but was limited by the
width of the birth canal of women. This natural limit of brain growth was first
circumvented by the postnatal growth phase of the child’s brain.
When these opportunities for brain enlargement were exhausted, evolution found a second way to overcome the limitations of the hominid brain. The brain of the individual did not grow any further but did communicate in a new manner with the brains of other group members, so that knowledge and tasks could be shared between the group members.
In this way, a network as we know it from PC networks, was created. With a larger postnatally completed and networkable brain, the biological premise for the evolution of the human mind was established. This is what we will now address.
Perhaps equally remarkable is the fact that since Homo sapiens reached this stage more than 100,000 years ago, there has been no further significant increase in brain size.
It is difficult to understand why natural selection gave primitive humans such a perfect brain that 100,000 years later it would enable the achievements of a Descartes, Darwin or Kant or the invention of the computer, trips to the moon or the literary creations of a Shakespeare or Goethe.
(Mayr 2002, p. 501)
I posed the question as to whether Ernst Mayr is right with the statement of
the perfect brain of Homo sapiens. Now here is the answer: Yes and no. He is
right, because the human brain has found a miracle cure, so to speak, with its
networking capabilities that enable it to access unlimited brain capacity via
But Mayr would not have been right if his contention that the brains of Descartes, Darwin or Kant alone would have done their great work without the help of the human network of clever forerunners, critical contemporaries, interested discussion partners, etc. had been understood in such a way.
The end of hominid brain growth is a paleoanthropologically verifiable fact that is associated with the appearance of modern Homo sapiens.