Final answer:
Biology supports the incest taboo by emphasizing the benefits of genetic diversity, which is compromised by inbreeding, leading to a greater risk of genetic defects. Sexual reproduction is favored in evolutionary terms because it increases the chances of beneficial genetic variations and reduces detrimental mutations.
Step-by-step explanation:
The incest taboo is a cultural norm prohibiting sexual relationships between closely related individuals, such as parents and their offspring. Biology supports this taboo through the concept of genetic diversity. When closely related individuals mate, the offspring are at a higher risk of inheriting detrimental recessive genes, leading to potential genetic disorders and reduced fitness. This is due to a lack of gene variety which can occur in inbreeding. Thus, from an evolutionary perspective, the taboo can be seen as a protective measure to maintain genetic health and prevent the accumulation of harmful mutations in populations.
In terms of kin selection, helping close relatives may increase the likelihood that one's genes are passed on. However, when it comes to mating, the biological rationale favors genetic diversity, as it can enhance the survival and adaptability of offspring. Moreover, research involving organisms like yeast has shown that sexual reproduction, which combines genetic material from two different individuals, can help purge detrimental mutations and potentially increase beneficial ones. The cultural prohibition against incest is thus supported by biology because it aids in preserving the health of future generations by preventing the concentration of negative genetic traits and enhancing the robustness against various environmental challenges.