Human biodiversity (HBD) is the diversity found among and between human populations that has a genetic basis. HBD is about the genetic diversity in anatomically modern humans (homo sapiens) and how this genetic diversity influences humans' culture and behavior. Genetic inheritance, the reality and significance of IQ, and the reality of biological sex and race differences all fall under HBD.
HBD is the idea that genetic differences do not stop at the species, but go much further, since one can genetically classify people into races, ethnicities, families, and so on, going down even to the level of the individual. Like other taxonomic classifications, one can classify these based on many attributes, such as eye color, skin color, tolerance against certain food, political views, intelligence, lifestyle, and so on. HBD is the acceptance of genetic diversity playing a big role in who people are and the application of this idea in many scientific fields such as evolutionary psychology, forensic anthropology, and population genetics.
HBD does not claim that race is a purely objective classification, since even other taxas such as species, subspecies and classes are subjective and up to debate. HBD does say that there are clear genetic variation in populations, and that therefore one can average the amount of genetic differences to create different classifications like race. HBD also does not claim that every single trait of humans is purely determined by genetics and that environmental factors do not exist. Rather, HBDers often consider the issue of nature vs. nurture fallacious and say that the two complement each other.
HBD also does not claim that white people are superior to other races, any more than they would say that a monkey is superior to a fish because a monkey can climb trees and fish cannot. HBD does cover how races are different from each other and how they evolved within their respective geographical locations. Examples would include how Inuits are able to consume food with higher amounts of fats without risking heart diseases because they evolved in a harsh climate where a low fat mediterranean diet is hard to come by; how only 10% of Nordic Europeans are lactose intolerant compared to 95% of sub-Saharan Africans and east Asians because Europeans knew that fermenting milk would reduce lactose in dairy products, helping them to adapt to the products; how some races have evolved different adaptations to high altitude; and how sub-Saharan Africans are the only race in which the MCPH1 gene, which is connected to brain development and tonal language, is exceptionally low.
HBD takes into account that even features that seem trivial at first, like hair color and eye color, can be linked to major differences in other attributes. For example, the gene HERC2, which determines blue eye color, can be found in chromosome 15 duplicons which can cause several genetic disorders like Angelman and Prader–Willi syndrome.
Part of the reason why HBD is controversial is that it accepts race as a potential taxonomic classification and accepts that racial differences are largely caused by genetics, an idea that contradicts the blank slate view in the nature vs. nurture debate that humans are largely shaped by environmental factors and social constructs.