Aristotle the Biologist

About a quarter of Aristotle's surviving writings concern living things, and many historians call him the founder of biology. Working especially around the lagoon of Pyrrha on Lesbos, he described hundreds of animals, dissected many, and tried to classify them by shared features such as blood, reproduction and body parts.

Some of his observations were remarkable: he recognized that dolphins breathe air, give birth to live young and nurse them, grouping them apart from fish, and he described an octopus's specialized mating arm, which was not confirmed until the 19th century.

He also made errors, partly because he relied on fishermen's and travelers' reports and lacked instruments, such as claiming the heart is the seat of thought. His method of systematic observation, classification and explanation by function set a pattern for natural science, even as later biologists corrected many of his conclusions.