Human Variation Are Humans Still Evolving

The Genus Homo and the Emergence of Us ANTH 2301 Natural Selection and Human Variation: Are Humans Still Evolving? A multitude of environmental and genetic factors, such as socioeconomic position, ethnicity, age, diet, quality of life, access to healthcare, employment and vocation, etc., are thought to contribute to human variability. As was noted in Chapter 1, anthropology offers valuable insights into the social construction of race as well as the effects that racial classifications have on individuals' daily lives. This chapter focuses on how natural selection contributes to human variety. The Neolithic age and the advent of agriculture between 10,000 and 8,000 years ago are linked to several developments. Numerous people have observed that neither the environment nor human health benefited from the changes that occurred during this time. According to Li, van Vugt, and Colarelli (2018), the evolutionary mismatch theory postulates that our bodies are most adapted to the habitats in which we have spent a large portion of our evolutionary history. These environments differ greatly from those in which we currently live. For a million years, humans were hunter-gatherers. Human bodies are still attempting to adjust to the mostly grain-based diet that agriculture has brought about, a diet that is less varied and less nutrient-dense than that of a normal hunter-gatherer. People are more prone to various illnesses and nutritional deficits as a result of their incomplete adaptation to this shift. One such instance is lactose intolerance. In recent evolutionary history, the agricultural period saw the beginning of the domestication of cattle and the use of cow's milk. Nowadays, 65 percent of people cannot properly digest cow's milk. Dental caries, or cavities, are another issue connected to the agriculturally-related diet shift. The meals of hunter-gatherers are vastly different from the grain-based, high-sugar diets linked to agriculture. Our bodies haven't had enough time to adjust to this shift, and neither have the bacteria in our mouths. Skin pigmentation variation is another adaptation that happened in the Neolithic age. About 40,000 years ago, humans fled Africa and settled in Europe. They most likely had dark skin with high melanin levels, which protects against UV radiation. According to new research, early hunter-gatherers in Spain, Luxembourg, and Hungary had darker skin 8,500 years ago. Depending on one's distance from the equator, different skin tones offer distinct benefits. Skin pigmentation is a response to UV exposure. Humans were exposed to less UV light when they relocated to the Northern Hemisphere, which resulted in decreased absorption of vitamin D, which is essential for healthy bones and other immune system processes. Skin pigmentation lightened to make up for this loss and to permit increased exposure to UV light. Native communities in the Andes, Tibet, and Ethiopian highlands are other examples of how environmental adaptation has led to human variety. Living in low-oxygen environments, all three of these taxa confront the same environmental problem, to which they have each developed unique adaptations. Tibetans breathe more often than individuals who live at sea level in order to make up for their low oxygen levels. It has been discovered that persons who live at high elevations in the Andes have blood that contains more haemoglobin than average. Ethiopians who reside between 9,800 and 11,580 feet above sea level do not have one of these adaptations. It is still unclear how the Ethiopian highlanders manage to survive in their natural habitat.