Comparative anatomy

Comparative anatomy

Comparative anatomy studies similarities and differences in organisms. The image shows homologous bones in the upper limb of various vertebrates.

Comparative anatomy is the study of similarities and differences in the anatomy of different species. It is closely related to evolutionary biology and phylogeny (the evolution of species).

Comparative anatomy has long served as evidence for

External links

  • Campbell, Neil A.; Reece, Jane B. (February 2002).  
  • Caldwell, Roy (2006). "Comparative Anatomy: Andreas Vesalius". University of California Museum of Paleontology. Retrieved 2011-02-17. Comparative Anatomy, pre-1800s 

References

  1. ^ Campbell, Neil A.; Reece, Jane B. (February 2002).  
  2. ^ Blits, K. C. (1999), Aristotle: Form, function, and comparative anatomy. Anat. Rec., 257: 58–63. doi: 10.1002/(SICI)1097-0185(19990415)257:2<58::AID-AR6>3.0.CO;2-I
  3. ^ Caldwell, Roy (2006). "Comparative Anatomy: Andreas Vesalius". University of California Museum of Paleontology. Retrieved 2011-02-17. Comparative Anatomy, pre-1800s 

Footnotes

See also

Today comparative anatomy is still taught and used, particularly in the field of paleontology.

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.

is regarded as the founder of comparative anatomy. He is credited with determining that marine mammals are, in fact, mammals. Also, he concluded that chimpanzees are more similar to humans than to monkeys because of their arms.

Edward Tyson
A drawing by Edward Tyson

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 animals such as oxen.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 you should make your 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 Galen. An interesting observation made by some of these physicians was the presence of homologous structures in a wide variety of animals which included humans. These observations were later used by Darwin as he formed his theory of Natural Selection.[3]

A posthumous painting of Andreas Vesalius

Born in 1517 Pierre Belon was a French naturalist who did 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 what is referred to as modern comparative anatomy.

The first specifically anatomical investigation separate from a surgical or medical procedure is associated by early commentators with Alcmaeon of Croton.[2]

A 20th century illustration comparing the bone-structures of a human and a dog.

History

Contents

  • History 1
  • See also 2
  • Footnotes 3
  • References 4
  • External links 5
The human heart (left) and chicken heart (right) share many similar characteristics. Avian hearts pump faster than mammalian hearts. Due to the faster heart rate, the muscles surrounding the ventricles of the chicken heart are thicker. Both hearts are labeled with the following parts: 1. Ascending Aorta 2. Left Atrium 3. Left Ventricle 4. Right Ventricle 5. Right Atrium

The rules for development of special characteristics which differ significantly from general homology were listed by Karl Ernst von Baer (the Baer laws).

  1. Homologous structures - structures (body parts/anatomy) which are similar in different species because the species have common descent. They may or may not perform the same function. An example is the forelimb structure shared by cats and whales.
  2. porpoises and sharks. So even though they evolved from different ancestors, porpoises and sharks developed analogous structures as a result of their evolution in the same aquatic environment.

Two major concepts of comparative anatomy are: [1]