What primarily drives the changes in allele frequencies that influence human traits over time?

Natural selection is the process that primarily drives changes in allele frequencies within a population over time. It occurs because individuals with certain traits that are better adapted to their environment are more likely to survive and reproduce, passing those advantageous traits to their offspring. Over generations, this can result in an increase in the frequency of alleles associated with these favorable traits in the population, leading to evolutionary changes.

In the context of human evolution, natural selection can influence a wide range of traits, from physical characteristics like skin color, which may be advantageous in different environmental conditions, to traits affecting health and disease resistance.

While environmental adaptation, phenotypic variation, and cultural influences do play roles in the evolution of humans and can impact allele frequencies indirectly through processes such as selection pressures, they are not the mechanisms that primarily drive allele frequency changes. Environmental adaptation describes how organisms respond to environmental changes, but it is natural selection that acts on the alleles related to these adaptations. Phenotypic variation refers to the differences in traits that arise within individuals of a population, and while it is necessary for natural selection to act upon, it is not the driving force itself. Cultural influences can affect human behaviors and, in some cases, specific traits (such as dietary habits), but they