order to appreciate Darwin’s reflections on the only gradual differences
between the mental abilities
of humans and animals, I must expound a bit more.
people of the Enlightenment recognised that the world was not always as it is
today, the first explanation was that the old world, the one that had been
discovered here and there in the form of the bones of extinct animals, had been
the first creation that had perished in the deluge narrated in the Bible.
gave rise to catastrophe theory, the
idea that there had been several acts of creation, and that the world had been
destroyed in between them by floods or enormous volcanic eruptions and
earthquakes. However, the geology of Darwin’s time had shown that many
processes in nature were not catastrophic but rather gradual and that they took
place in small and even tiny steps.
Scottish geologist James Hutton had
gained experience from known remains out of the Roman era with just how slowly
geological processes take place. He also had recognised that the geological
faults that could be observed on the coasts of his Scottish homeland had to
have taken an incredible amount of time to form. This gave rise to the theory
of gradualism which attributed the
changes in the world to a continuous, gradual sort of change.
Our brain has developed in co-evolution with culture (p.15)
In Donald’s work, it is not an issue of two independent creatures or of mutual selection pressure but rather a mutual benefit of culture and brain. If culture, like the brain, were a human organ, we could speak of a symbiosis. Regardless of the terms, it is clear what Donald means.
According to his hypothesis, the human brain has developed together with human culture; brain and culture are dependent on each other. Donald can rely thereby on Charles Darwin, who explained in the Descent of Man: :
A great step in the development of intellect must have taken place as soon as semi-artificial and semi-intuitive language were used; for the constant use of language will have had an effect on the brain and produced a hereditary effect; and this in turn will have benefited the perfection of language.
Previous explanations of the origin of the human mind and human culture all assume a co-evolution of mind and brain, whereby mind and brain have influenced the evolution of each other (examples for co-evolution: insects and flowers, lions and gazelles).
statements contradict the prohibition of targeted evolution (Hypothesis 2) and
should therefore be rejected. The human mind is an evolutionary innovation and
therefore cannot have arisen via co-evolution.
Steidle defines the concept of co-evolution
in his contribution to the non-fiction book Evolution
Co-evolution occurs when two or more species influence each other’s evolution. This happens because each species exerts selection pressure on other species and changes itself in response to the selection pressure of other species. The consequence of co-evolution is the co-adaptation of the species involved. (Johannes Steidle 2009: Coevolution, in: Schmid, Ulrich und Günter Bechly (ed.): Evolution. Der Fluss des Lebens, Stuttgart, p. 81-88, p. 81)
can only be described in such a way that the advantages of emerging or changing
are clear at every stage of development. Plumage, which – like the fur of mammals – serves to maintain body heat and only developed feathers became useful for active flying and gliding much later, is plausible in the sense of evolution because the selection advantage becomes visible at each and every stage of evolution as well as in every generation of living beings.
According to Darwin, biological evolution is open-ended and not targeted. That means evolution cannot be understood in terms of its goal, instead in terms of its starting point. A causal chain of argumentation must be built up from the starting point. (Example: feathers were not created to allow the birds to fly.)
Mayr wrote about this in his great work, The
Growth of Biological Thought:
Darwin’s theory uncompromisingly rejects the existence of definitive factor in the cause of evolutionary change
(German: Ernst Mayr 2002: Die Entwicklung der biologischen Gedankenwelt, Berlin et al., p. 417)
to Darwin, the development of humans from the animal kingdom
also includes the development of mental abilities in humans. He wrote:
If no organic being except for humans had any spiritual power, or if our powers were fundamentally different from those of animals, we would never be convinced that our high abilities had gradually developed.
However, it can be shown that there really is no fundamental difference of this kind. One must admit that the gap between the intellectuality of a high-developed monkey and that of a lower fish, perhaps something like a lamprey or lancet fish, is much larger than the gap between monkeys and humans. (p. 81)
However, it can be shown that there really is no
fundamental difference of this kind. One
must admit that the gap between the intellectuality of a high-developed monkey
and that of a lower fish, perhaps something like a lamprey or lancet fish, is
much larger than the gap between monkeys and humans. (p. 81)
As a biological being, humans are part of nature and, like all other living beings, have developed over the course of evolution. The development of the human mind can therefore also only be explained appropriately on the basis of Darwin’s theory of evolution.
1758 Carl von Linné incorporated man into his taxonomic work Systema Naturae, which is still fundamental
today. He placed humans quite naturally next to their next animal relatives,
the great apes, and summarised both in an order, which he later called primates (master animals).
defended himself against criticism related to this approach, arguing that he
could find no significant difference between the skeletons of humans and those