An organism best fits the environment described by its genes, an environment that prevailed
during the time period (millions of years) when evolution naturally selected the genes of its
ancestors—those who survived to pass on their genes. When an organism's current
environment differs from its ancestral one, the environment's mismatch with the organism's
genome may result in functional disadvantages for the organism. The genetically
conditioned nutritional requirements of human beings established themselves over millions …