Both their own individual life experiences and the evolutionary history.
What about biological anthropologists?
Since genes are the main cause of human diversity, they can look at genes.
Since differences in health are the primary cause of most human diversity, they can research health.
Understanding human adaptation to various settings, the causes of illness and early mortality, and how humans descended from other animals are all goals of biological anthropologists.
They research people (alive and deceased), other primates including monkeys and apes, as well as human predecessors, to achieve this (fossils).
The study of biological anthropology focuses on the variety and environmental adaptations of our closest living relatives, monkeys and humans, as well as their evolutionary history.
The strong evolutionary perspective of biological anthropology is one of its key features.