The Interconnected Genomic and Cerebral Evolution that Shaped Human Origins

Wayne State University, Detroit MI

Investigators

Abstract

This research team is conducting a genome-wide search for advantageous genetic changes in humankind's ancestry. A focus is on discovering the genetic changes that shaped humankind's enlarged brain and complex cognitive abilities. The first step in the method of discovery is to identify the many thousands of genes encoding proteins that function in the cerebral cortex of humans and other catarrhine primates such as chimpanzees, gorillas, and rhesus monkeys. Next, for these cerebral cortical brain expressed genes, determine which ones show species differences in expression patterns, especially identify those genes with expression patterns that differ between humans and the other catarrhines. Finally, by data mining take full advantage not only at the completed DNA sequence of the human genome but also of the soon to be completed chimpanzee genome and, for many of the genes of interest, the growing bodies of DNA sequence data from a range of primates. With this mined sequence, data for genes of interest (those that cerebral cortical cells express) identify by phylogenetic analysis the actual mutational changes that occurred either in gene regulatory regions or in protein encoding regions and that were favored by natural selection. Results obtained so far indicate that both types of mutational changes, gene regulatory and protein-encoding, shaped the distinctive features of the human phenotype. By combining the considerable expertise of geneticists, biochemists, neuroscientists, and anthropologists, this research will bridge diverse disciplines in order to elucidate the linked genotypic-phenotypic evolution of the human brain and thereby contribute to studies that seek a fundamental understanding of human origins. This research should have broad societal impact. It will increase understanding of the genetic underpinning of the enlarged brain humans have. In doing so, it will identify those encoded proteins and DNA regulatory elements that evolved in more recent human ancestry under the force of positive selection. This information could be of great value in the field of mental health such as in the search for new therapeutic agents for mental health practitioners.