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  • Essay / The Human Brain: Size and Development - 1552

    Over time, the human brain has become an amazing organ of the human body. It can store a lot of information that is essential for the survival of the human race and success in life. The brain has evolved and grown, it has always been difficult to understand what caused this growth and development. Microcephalin and abnormal spindle microcephaly-associated proteins, or ASPM, are the genes responsible for brain size and development and are responsible for mutations seen in affected individuals that result in truncated gene products. Among all mammals, humans have exceptionally large brains relative to their body size. There is evidence that the ASPM gene is an important genetic element in the evolutionary expansion of the human brain. Evidence has shown that the ASPM gene appears to have been under positive selection for a long time. It is really difficult to estimate when the ASPM gene might have undergone positive selection, but it has been estimated to be around the time the human brain began to develop, which is between 0.2 and 0.4 years ago. million years. Recent studies have shown that the ASPM gene is not currently undergoing positive selection (Zhang). Another explanation for positive selection on ASPM concerns its role in germ cell proliferation. Many scientists have proposed that the ASPM gene may be subject to sexual selection acting on sperm development or function. However, there is no association between ASPM and relative testes size in anthropoids. However, there is little evidence that this type of selection is possible. It is possible that the association between the rate of evolution of loci with the evolution of the brain, or the evolution of...... middle of article...... Ganeshwaran H. Mochida, John I. Risinger, Paul Goldsmith, Michelle Gunsior, Greg Solomon, William Gersch, Jung-Hyun Kim, J. Carl Barrett, Christopher A. Walsh, Jerzy Jurka, Hiroshi Masumoto, and Vladimir Larionov. “The microcephaly ASPM gene is expressed in proliferating tissues and encodes a mitotic spindle protein.” 2:15 p.m. (2005): 2155-165. June 22, 2005. the web. February 10, 2014. Montgomery, Stephen H. and Nicholas I. Mundy. “THE EVOLUTION OF ASPM IS ASSOCIATED WITH BOTH INCREASE AND DECREASE IN BRAIN SIZE IN PRIMATES.” 66.3 (2011): 927-32. 2012. Internet. February 18, 2014. Wang, Yin-qiu and Bing Su. “Molecular evolution of microcephalin, a gene determining human brain size.” 13.11 (2004): n. page. 2004. Internet. February 10, 2014.Zhang, Jianzhi. “Evolution of the human ASPM gene, a major determinant of brain size.” (2003): n. page. Genetics Society of America, 2008. Web. February 10. 2014.