Biogeography is a branch of biology that examines how populations adapt to different ecosystems and how geography impacts organisms and populations. Wilson is famous for pioneering the subfield of island biogeography, which explores the process through which living things arrive on islands and diversify in a small space.

Entomology is the study of insects. Entomologists might examine insect evolution; how insects interact with each other and with other organisms in their environment; insect interactions with crops, livestock, and humans; or how insect populations proliferate and decline. Wilson was primarily an entomologist specializing in cataloging the world’s ant species.

Evolution describes the process whereby all life on Earth developed through random genetic mutations. These mutations caused differentiation among life forms, eventually resulting in a vast array of different species. Charles Darwin was the first scientist to correctly identify the mechanism for evolution: natural selection, wherein favorable mutations stick around, and unfavorable ones die out.