Are Human Brains Unique?

Michael Gazzaniga, one of the world’s leading neuroscientists, is a Professor of Psychology and the Director for the SAGE Center for the Study of Mind at the University of California Santa Barbara. Here follows an abridged version of the summary of his last contribution to edge.org:

“Scientists compared the genetic sequences of ethnically and geographically diverse people from around the world and found that the genes which code for the nervous systems, had some sequence differences (known as polymorphisms) among individuals. They calculated that one genetic variant of microcephalin arose approximately 37,000 years ago, which coincides with the emergence of culturally modern humans, and it increased in frequency too rapidly to be compatible with random genetic drift or population migration. This suggests that it underwent positive selection. Another variant arose about 5800 years ago, coincident with the spread of agriculture, cities and the first record of written language. It too is found in such high frequencies in the population, that it indicates strong positive selection.”

Read on at Edge…