Natural selection and genetic drift are among the evolutionary forces that have influenced human variation within and between modern populations of humans. In terms of human selection, modern humans have ended up developing “lifestyle strategies to cope with and even thrive in a wide range of habitats” (Shook, et al. 11). On the other hand, genetic drift has influenced changes in physiological changes as a result of evolution, and this has also led to human to develop adaptations to cope with and even thrive in a wide range of habitats. Several adaptations have helped humans survive in different environments.
Adaptation is “The long-term, micro-evolutionary i.e., genetic changes that occur within a population in response to an environmental stressor” (Shook, et al. 11). According to revolutionaries, adaptation means a “phenotypic trait, either physiological or morphological feature or behaviour that has been acted upon by natural selection processes to increase a species’ ability to survive and reproduce within a specific environment” (Shook, et al. 10). Most adaptation traits have a significant role to play and beneficial in nature.
Altitudinal adaptation involves how human genotypes tend to behave in indigenous high-altitude populations in a different environment. The three regions mentioned to have high-altitude indigenous populations are Tibet, the Andes, and Ethiopia. The population from these religions share “common genetic traits based on relatively similar evolutionary histories influenced by similar environmental stressors” (Shook, et al. 11). It means environment conditions influence local genetically based adaptation, but we are reminded that “not all adaptations are related to life in high-altitude environments” (Shook, et al. 11).
Another adaptation is about human skin tone. Have you ever asked yourself why some of your friends are darker than you? Skin tone is a “reflection of the complex evolutionary history of our species” (Shook, et al. 11). The two substances that are produced in the body to regulate skin tone are melanin and haemoglobin, but the production of melanin varies from one individual to another and depends on the climate of geographical places where human is adapted. Adaptation of body shape and size of the individuals also depends on climatic conditions. I discovered that most modern human adaptations rely on the climate of a specific environment.