Final answer:
Sexual attraction and genetic expression in both humans and nonhuman animals support the idea of natural selection, which is the survival and propagation of individuals with favorable traits.
Step-by-step explanation:
Studying sexual attraction in humans as well as nonhuman animals in terms of genes and their expression gives support to the idea of natural selection.
Sexual reproduction provides a potent source of genetic variation, which is the raw material upon which natural selection acts. Through the breeding process, genetic material is reshuffled, giving rise to offspring with unique combinations of genes. Over time, these genetic variations may influence an organism's evolutionary fitness, with those individuals possessing advantageous traits more likely to survive, reproduce, and pass on their genes. This continuous process ensures that populations adapt and evolve in response to environmental pressures.
The concept of natural selection was first proposed by Charles Darwin, who used the observable phenomenon of artificial selection as an analogy. He posited that in natural environments, traits that enhance survival and reproductive success would become more prevalent over successive generations. Thus, natural selection leads to the propagation of favorable heritable traits, contributing to evolutionary change within populations.