Comparative Anatomy

“There are many forms of evidence for evolution. One of the strongest forms of evidence is comparative anatomy; comparing structural similarities of organisms to determine their evolutionary relationships.”

Comparative Anatomy

Comparative anatomy involves comparing the body structures of two species. 'Comparative' means to look at the similarities between two things, and 'anatomy' has to do with the structure of the body. Scientists can look at anatomical structures of seemingly unrelated animals to tell how related they are. There are many forms of evidence for evolution. One of the strongest forms of evidence is comparative anatomy; comparing structural similarities of organisms to determine their evolutionary relationships. Organisms with similar anatomical features are assumed to be relatively closely related evolutionarily, and they are assumed to share a common ancestor. As a result of the study of evolutionary relationships, anatomical similarities and differences are important factors in determining and establishing the classification of organisms. Some organisms have anatomical structures that are very similar in embryological development and form, but very different in function. These are called homologous structures. Since these structures are so similar, they indicate an evolutionary relationship and a common ancestor of the species that possess them. A clear example of homologous structures is the forelimb of mammals. When examined closely, the forelimbs of humans, whales, dogs, and bats all are very similar in structure. Each possesses the same number of bones, arranged in almost the same way. While they have different external features and they function in different ways, the embryological development and anatomical similarities in the form are striking. By comparing the anatomy of these organisms, scientists have determined that they share a common evolutionary ancestor and in an evolutionary sense, they are relatively closely related.

Comparative anatomy explores and establishes the correspondences between body parts of organisms from different species. It builds the concepts of the living structures and thus must not be confused with morphology (the study of the forms and their variations) nor with Evo-Devo (the study of the relations between the genetics of the development and evolution). Without comparative anatomy, naming, and understanding what can be seen in organisms would be impossible. Then, neither descriptive embryology, causal embryology, phylogeny, palaeontology nor systematics could be conducted and the understanding of both biology and evolution of species would be dead-end streets. Examining several organisms, we can establish functional correspondences (as between a wing of a fly and one of a pigeon) and correspondences of origin (as for a wing of a fly and one of a mosquito). These must not be confused, because they are different. Comparative anatomy is the study of both the functional adaptation, where the first type of correspondences plays the main role and the phylogeny, where it is assumed that the second type of correspondences is important.

Citations:

The Editors of Encyclopaedia Britannica. “Comparative Anatomy.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 16 Jan. 2020, www.britannica.com/science/comparative-anatomy. STUDY.COM, study.com/academy/lesson/what-is-comparative-anatomy-definition-ex amples.html. “Comparative Anatomy.” Structures, Evolutionary, Organisms, and Common - JRank Articles, science.jrank.org/pages/348/Anatomy-Comparative.html. “The Importance of Comparative Anatomy.” AcanthoWeb, www.acanthoweb.fr/en/content/importance-comparative-anatomy.