May 22 : Intl. Day of Biological Diversity & Aristotle

On International Day of Biological Diversity we remember Aristotle, the father of Biology. The word itself comes from Greek, meaning the study of life. Biology is the study of life and living organisms. It is a vast field that encompasses everything from the smallest microorganisms to the largest animals. The history of biology dates back to ancient times, with early civilizations such as the Egyptians and Greeks making observations about the natural world around them. However, it was Aristotle who is widely considered to be the founder of biology as a science.

Aristotle: Father of Biology

Aristotle was a Greek philosopher who lived from 384-322 BCE. He was a student of Plato and went on to become a teacher of Alexander the Great. Aristotle was interested in all branches of knowledge, including biology. He made detailed and systematic observations of the natural world, particularly the marine life around the island of Lesbos where he spent about two years. His observations were recorded in his books on biology, which formed about a quarter of his writings that have survived.

Aristotle’s theory of biology was grounded in systematic observation and collection of data, mainly zoological. His theory is based on his concept of form, which derives from but is markedly unlike Plato’s theory of Forms. Aristotle’s method resembled the style of science used by modern biologists when exploring a new area, with systematic data collection, discovery of patterns, and inference of possible causal explanations from these. He did not perform experiments in the modern sense, but made observations of living animals and carried out dissections. Aristotle names some 500 species of bird, mammal, and fish; and he distinguishes dozens of insects and other invertebrates. He describes the internal anatomy of over a hundred animals, and dissected around 35 of these.

Aristotle’s Impact on Biology

Aristotle’s main biology texts were the History of Animals, Generation of Animals, Movement of Animals, Progression of Animals, Parts of Animals, and On the Soul, as well as the lost drawings of The Anatomies which accompanied the History. His work was influential in the medieval Islamic world. Translation of Arabic versions and commentaries into Latin brought knowledge of Aristotle back into Western Europe, but the only biological work widely taught in medieval universities was On the Soul. The association of his work with medieval scholasticism, as well as errors in his theories, caused Early Modern scientists such as Galileo and William Harvey to reject Aristotle. Criticism of his errors and secondhand reports continued for centuries. He has found better acceptance among zoologists, and some of his long-derided observations in marine biology have been found in modern times to be true.

In conclusion, Aristotle’s contributions to the field of biology were significant. He was the first to attempt a system of animal classification, in which he contrasted animals containing blood with those that were bloodless. He also drew important distinctions between animals with and without blood and between viviparous and oviparous animals. Aristotle’s biological science is important to understand, not only because it gives us a view into the history and philosophy of science, but also because it allows us more deeply to understand his non-biological works, since certain key concepts from Aristotle’s biology repeat themselves in his other writings.

Below is a great BBC documentary by Imperial College professor Armand Leroi that explains how Aristotle founded Biology on the Greek island of Lesvos. It is based on his book, The Lagoon: How Aristotle Invented Science. Over 2000 years before DNA was discovered, Aristotle was already talking about it conceptually, as you will see in the documentary Aristotle’s Lagoon: