Evolution of man in the light of molecular genetics: a review. Part II. Regulation of gene function, evolution of speech and of brains.
In the first part of this review the evolutionary history and genomics of the human species were considered in the light of molecular genetic evidence. In this second part the emphasis will be put on the regulation of the function of the genes and evolution of the human-specific traits such as enormously large brains and the capacity to communicate with a spoken language. The age-old question of what specifically makes us humans is also dealt with in its new lightning of molecular genetics of the genome era. It is concluded that, in addition to the structural differences of the genomes, it is most likely that it is different pattern of the regulation of the function of the genes, which evolved for most part through positive natural and sexual selection where the growth and the structure of the human population played a significant role, that differentiates us from our closest living relatives. In this process of the evolution of the most human-specific characteristics, like the size of brains, specifically that or the neocortex, and ability to speak, interbreeding with other forms of the Homo-genus may have played a role. In addition to the role of positive selection in general in the evolution of different human-specific traits, it is evident that this progressive selection has been quite effective, thus leading to accelerated evolution of these traits. Finally it can also be concluded that genetic and cultural evolution have gone hand in hand during the recent, and still continuing, evolution of the mankind interacting with each others in a bidirectional fashion.
Portin
Petter
P
Laboratory of Genetics, Department of Biology, University of Turku, Turku, Finland. petter.portin@utu.fi
D001921:Brain; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D015894:Genome, Human; D006801:Humans; D012045:Regulatory Sequences, Nucleic Acid; D013060:Speech