, 1555 The first specifically anatomical investigation separate from a surgical or medical procedure is associated by
Alcmaeon of Croton.
Leonardo da Vinci made notes for a planned anatomical treatise in which he intended to compare the hands of various animals including bears.
Pierre Belon, a French naturalist born in 1517, conducted research and held discussions on
dolphin embryos as well as the comparisons between the skeletons of birds to the skeletons of humans. His research led to modern comparative anatomy. Around the same time,
Andreas Vesalius was also making some strides of his own. A young anatomist of Flemish descent made famous by a penchant for amazing charts, he was systematically investigating and correcting the anatomical knowledge of the Greek physician Galen. He noticed that many of Galen's observations were not even based on actual humans. Instead, they were based on other animals such as non-human
apes,
monkeys, and
oxen. In fact, he entreated his students to do the following, in substitution for human skeletons, as cited by Edward Tyson : "If you can't happen to see any of these, dissect an Ape, carefully view each Bone, &c. ..." Then he advises what sort of Apes to make the choice of, as most resembling a Man : And conclude "One ought to know the Structure of all the Bones either in a Humane Body or in an Apes ; 'tis best in both ; and then to go to the Anatomy of the Muscles." Up until that point, Galen and his teachings had been the authority on human anatomy. The irony is that Galen himself had emphasized the fact that one should make one's own observations instead of using those of another, but this advice was lost during the numerous translations of his work. As
Vesalius began to uncover these mistakes, other physicians of the time began to trust their own observations more than those of Galen. An interesting observation made by some of these physicians was the presence of homologous structures in a wide variety of animals, even including humans. These observations were later used by
Darwin as he formed his theory of
Natural Selection.
Edward Tyson is regarded as the founder of modern comparative anatomy. He is credited with determining that
whales and
dolphins are, in fact, mammals. Also, he concluded that
chimpanzees are more similar to humans than to
monkeys because of their arms.
Marco Aurelio Severino also compared various animals, including birds, in his
Zootomia democritaea, one of the first works of comparative anatomy. In the 18th and 19th century, great anatomists like
George Cuvier,
Richard Owen and
Thomas Henry Huxley revolutionized our understanding of the basic build and
systematics of
vertebrates, laying the foundation for
Charles Darwin's work on
evolution. An example of a 20th-century comparative anatomist is
Victor Negus, who worked on the structure and evolution of the larynx. Until the advent of genetic techniques like
DNA sequencing, comparative anatomy together with
embryology were the primary tools for understanding
phylogeny, as exemplified by the work of
Alfred Romer. ==Concepts==