Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Evolution of the Human ASPM Gene, a Major Determinant of Brain Size

Evolution of the Human ASPM Gene, a Major Determinant of Brain Size The size of human brain tripled over a period of ∼2 million years (MY) that ended 0.2–0.4 MY ago. This evolutionary expansion is believed to be important to the emergence of human language and other high-order cognitive functions, yet its genetic basis remains unknown. An evolutionary analysis of genes controlling brain development may shed light on it. ASPM (abnormal spindle-like microcephaly associated) is one of such genes, as nonsense mutations lead to primary microcephaly, a human disease characterized by a 70% reduction in brain size. Here I provide evidence suggesting that human ASPM went through an episode of accelerated sequence evolution by positive Darwinian selection after the split of humans and chimpanzees but before the separation of modern non-Africans from Africans. Because positive selection acts on a gene only when the gene function is altered and the organismal fitness is increased, my results suggest that adaptive functional modifications occurred in human ASPM and that it may be a major genetic component underlying the evolution of the human brain. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Genetics Oxford University Press

Evolution of the Human ASPM Gene, a Major Determinant of Brain Size

Zhang, Jianzhi
Genetics , Volume 165 (4): 8 – Dec 1, 2003
Download PDF
8 pages

Loading next page...
 
/lp/oxford-university-press/evolution-of-the-human-aspm-gene-a-major-determinant-of-brain-size-0mXCXQ9oVy

References (40)

Publisher
Oxford University Press
Copyright
© Genetics 2003
ISSN
0016-6731
eISSN
1943-2631
DOI
10.1093/genetics/165.4.2063
Publisher site
See Article on Publisher Site

Abstract

The size of human brain tripled over a period of ∼2 million years (MY) that ended 0.2–0.4 MY ago. This evolutionary expansion is believed to be important to the emergence of human language and other high-order cognitive functions, yet its genetic basis remains unknown. An evolutionary analysis of genes controlling brain development may shed light on it. ASPM (abnormal spindle-like microcephaly associated) is one of such genes, as nonsense mutations lead to primary microcephaly, a human disease characterized by a 70% reduction in brain size. Here I provide evidence suggesting that human ASPM went through an episode of accelerated sequence evolution by positive Darwinian selection after the split of humans and chimpanzees but before the separation of modern non-Africans from Africans. Because positive selection acts on a gene only when the gene function is altered and the organismal fitness is increased, my results suggest that adaptive functional modifications occurred in human ASPM and that it may be a major genetic component underlying the evolution of the human brain.

Journal

Genetics – Oxford University Press

Published: Dec 1, 2003

There are no references for this article.