When all studies are combined they indicate that the DNA sequence of brain genes show many changes in expression and copy number during the evolution of humans. Studies of non-coding DNA identified significant changes in a number of brain-specific genes during the evolution of man.
Among the non-brain genes, the greatest selective forces have occurred in those for smelling and hearing; immune defenses especially against viruses; amino acid metabolism to allow for the greater energy requirements of the enlarging brain; and spermatogenesis.
The fact that human and chimp genes are vastly more similar (99%) than they are different (1%) provides overwhelming evidence that man evolved from the apes. [p182]
