ABSTRACT
The genetic basis of phenotype variation is commonly determined by experimental or observational studies within species. The discovery of the genetic changes behind the evolution of uniquely human traits has been relatively slow compared with the pace of the generation of whole genome sequences, and of the elucidation of the genetic bases of human diseases. Human language abilities are certainly complex in terms of their biological basis and result from the interaction of many genes. Comparative studies of behavior, morphology, and genetics in humans and nonhuman primates have made significant progress in revealing individual phenotypic and genetic signatures of human uniqueness. The greatest consistent difference in gene expression patterns between humans and chimpanzees is seen in the testis. Expression patterns in brain are conserved, but show relatively higher rates of change during human compared with chimpanzee evolution.
