Final answer:
Fish argues that human biological races are nonexistent since the concept is not supported by scientific evidence. Instead, race is a social construct that fails to accurately classify humans based on genetic variations. The scientific community favors viewing human diversity through ancestry rather than outdated racial categories.
Step-by-step explanation:
In Mixed Blood, Fish presents the argument that human biological races do not exist because the concept of race lacks scientific validity. Significant scientific consensus from anthropologists, biologists, and geneticists supports the idea that traditional racial categorizations do not reflect the actual biological diversity within the human species. This is evidenced by the minimal number of genetic markers, such as those controlling for skin pigmentation, which do not align well with racial categories. Moreover, the vast genetic variation found within any given racial group is comparable to, or exceeds, the variation between different racial groups.
Race is described as a social construction rather than a biologically accurate way to categorize humans. It remains a potent societal tool, influencing practices and institutions despite its biological invalidity. Most research, including from biological anthropology and social sciences, suggests that our common notions of race are outdated. Instead, human traits are distributed along a spectrum, with far too much overlap between individuals to support discrete racial biological categories.
With the sequencing of the human genome, scientists argue that race is largely irrelevant to genetic research and that a focus on ancestry could provide a more accurate understanding of human genetic diversity. As such, the concept of race is viewed as a social construct that has been used historically for discrimination and other societal functions, rather than an identifier with a basis in biology.