This article proposes more than it should. It assumes humans were 'tied' to sea food and stayed near water before long overland migrations. They didn't know what they 'needed' biochemically, but the mutation does allow for brain growth and is undoubtedly important since it allows for plant consumption to substitute for sea food.-http://www.sciencedaily.com/releases/2012/09/120919190100.htm-
"This variation would have allowed early humans to convert plant-based polyunsaturated fatty acids (PUFAs) to brain PUFAs necessary for increased brain size, complexity and function."- This takes it too far: "This may have kept early humans tethered to the water in central Africa where there was a constant food source of DHA," Chilton said. "There has been considerable debate on how early humans were able to obtain sufficient DHA necessary to maintain brain size and complexity. It's amazing to think we may have uncovered the region of genetic variation that arose about the time that early humans moved out of this central region in what has been called the 'great expansion.'"