MODERN HUMAN EVOLUTION The concept of modern human evolution refers to the genetic drift patterns and adaptation that have occurred within the anatomically modern humans, who first appeared in the Middle Paleolithic period. Some modern man was isolated for many thousands of years, which has led to genetic variation of the species. There have been selection pressures on modern man that mainly affected those in Eurasia and in sedentary farmers, partly because of the rise and fall of glaciers. There are some humans who adapted to specific climates, such as those who can tolerate high altitudes. Some of this was acquired by interbreeding with archaic humans. Some studies have shown that mixtures with Neanderthals led to changes in hair color, risk for depression, smoking addiction, sleeping patterns, skin tone, and height differences in humans. The last glacial maximum led to selection pressures in the Eurasian human. Phenotypes linked to Caucasian skin coloring dates back to 19,000 years ago during the last glacial maximum. Blue eyes date back to 14,000 years ago in Italy and in the Caucasus. The adaptation leading to the cold climate adaptation seen in Inuit populations also dates back to the last glacial maximum period about 20,000 years ago. The largest brain volumes is seen in people who come from the Arctic and Siberia. The Holocene period involved large evolutionary adaptations in humans. This period of time was when there were more farmers in Eurasia, changes in diets, and the domestication of animals. East Asians developed the ability to digest lactose and learned rice domestication. Certain individuals who practiced extended free diving in the ocean had an enlarged spleen so they could hold more oxygen-rich blood cells. Menopause has been occurring later, especially since industrializations. Some populations have had selective pressures that lead to lower blood pressure, lower cholesterol, and lower blood sugar levels. The human reproductive period has lengthened.
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