Final answer:
Scientific evidence indicates that race is not a valid biological concept because genetic variation is not consistent with racial categories, making race a social construct without a biological basis.
Step-by-step explanation:
The question asks why is the human race not a valid concept as a biological construct. Multiple scientific disciplines including anthropology, biology, and genetics, have provided evidence that race cannot be biologically defined with precision. There are only a few genetic markers, such as those for skin pigmentation, that align with our social categories of race, which are folk taxonomies and not indicative of discrete biological groups. The overall genetic variation within any given racial group is often as great or greater than the variation between different groups. Biological anthropology has shown that human traits like skin color, facial features, and blood type do not segregate the human population into distinct racial categories. Hence, the concept of race does not translate to humans because there is no consistent biological basis for it; race is instead a social construct that varies across cultures and has no grounding in our genetics.