Julia Friend
Author: Mickie Anderson
Source: http://www.sciencedaily.com/releases/2013/12/131218130150.htm
Published: December 18, 2013
Summary:
Scientists have long thought that there were merely three known African crocodile species, but now it has come to light that there are at least seven. These species were recently identified by differences in genetics and physical features from the known species; a study between skulls has given significant evidence. Similarly, these newly named species are geographically separated.
The distinction in taxonomy is significant when it comes to the conservation of species. The distinction between the newly discovered West African crocodile and its Central African relative led to the discovery that is in the top four most endangered crocodiles in the world. Agencies dedicated to protecting the crocodiles need to use their money and resources efficiently by focusing on specific species like the West African. Additionally, the new classifications stops zoos from wasted efforts in trying to breed two different species.
Connection:
The article relates to both evolution and classification. It cites the differences between similar crocodile species; because they are so closely related that they previously could not have been told apart, all likely have a common ancestor. The different species are "geographically separated", which connects to geographic isolation. These various terms are all ones we have explored in class notes (common ancestor and geographic isolation). The article additionally addresses the disparity between species in that they cannot interbreed, which is the biological definition of "species" we were given.
The scientists classification of the crocodiles also relates to our class's identification of the bugs we used in the Wolbachia project. We, like the biologists, had to use physical information about the organism to categorize it.
Do the scientists know whether or not the different species originated from the same ancestor or were at once the same species? If not, are they making an effort to find out if the characteristics in the crocodiles are analogous, due to convergent evolution, or are simply homologous structures?
ReplyDeleteFrom what I gather, the evidence points to a common ancestor. Convergent evolution brings about analogous structures and therefore similar species; here the species so closely resembled one another that scientists could not differentiate for a long time. Similarly, in this article and others it points to geographic isolation helping to speciate, implying that there was a common starting point.
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