Discover the Biological Sciences
The introductory information for this site has been contributed as a joint assignment by students in Bio. Sci. 10.
By: Lucas KrallName: Sierra College Bio. Sci. 10
1) Biological field or sub-topic chosen:
A very important and remarkable field of biology is Comparative Anatomy. Simply put, Comparative Anatomy is broken into the concepts of homology (homologous structures) and analogy (analogous structures). Homology is the comparison and contrast of common anatomic structures/parts of one species to another due to their common ancestry. Often times, these anatomic structures/parts are used similarly among different species. Yet, the structures/parts have evolved according to the individual species’ environment and need to maintain a high level of reproduction and their need for survival. Where as analogy is the comparison of similar structures within animals from different ancestral backgrounds but come from similar environments. A common example is the comparison of the wings on butterflies and birds. These two species come from different backgrounds. However, their wing structure is universal for flying.
An important concept in Comparative Anatomy is the forelimbs of all mammals. Each mammal (i.e. cat, human, whale, bat) has homologous forelimbs. At first glance one could argue that a whale’s flipper has no similarities with a human arm. However, a deeper look at the skeletal structures will reveal a different story. In fact, they’re strikingly similar. This supports the hypothesis that all mammals came from the same ancestor, but through time and differing environments various adaptations were made and the species split into their respective branches.
The most interesting piece of information I came across pertained to the human spine. Through evolution our ancestral spinal structures eventually became erect into the posture we know today. This is shown on the basic diagram that depicts the progression from monkey to human. But what I didn’t know is that a common cause of back problems directly relates to our ancestral spinal columns. Through evolution our spine took a new role of support for our bodies and it would appear that all the kinks have not been worked out.