The Myosin Frameshift Mutation and Expansion of the Cerebral Cortex

The myosin heavy chain gene MYH16 is expressed in the masticatory muscles of primates which are considerably more powerful than the gracile masticatory muscles of humans.

MYH16 is a highly conserved throughout the primate family, including Australopithecus and Paranthropus, but approximately 2.4 million years ago a inactivating frameshift mutation occured in the gene in the lineage leading to humans ( ).

The MYH16 frameshift mutation is the first gene mutation unique to humans that can be correlated with a morphological change documented in the fossil record..

The FOXP2 Gene Mutation - The Remodeling of Human Vocalization

The FOXP2 gene resides on human chromosome 7 (7q31) and belongs to the "forkhead" family of winged-helix transcription factors and is believed to play an important part in the development of speech in human language.

The FOXP2 transcription factor product appears to control a gene cascade associated with the vocalization capacity of mammals ( ).

The human version of FOXP2 underwent a conserved gene mutation approximately 200,000 years ago around the same time as the modern vocal tract of extant humans began to emerge.