Homologus Traits
The two species that acquire the Homologus Trait are chimpanzees and humans. There is much debate about the relationship of evolution in regards to humans and primates, but humans and primates have some similar traits. The trait I am focusing on between the two species are opposable thumbs.
"Homologous traits are evidence of a shared ancestry." Although there are many similarities to human and chimpanzee hands there are also differences which set them apart and have them on different branches. The human hand's thumb is longer, more muscular, and more mobile than a primates thumb; there other fingers are shorter and flatter in comparison to primates. The Chimpanzee's thumb is much shorter to create a better grasp for swinging on trees, along with their longer and curved fingers to assist with that task as well. Primates hands are also not as flexible because they use their knuckles for walking and need more support.
Chimpanzees and Humans originate from the animalia kingdom within the Mammalia class.The class the Anthropoidea came before the Hominoidea (apes and humans) branch according to the textbook Introduction to Physical Anthropology. The earliest fossils were found in East Africa. These decedents are distinguished from old world monkeys by a larger nasal and palate region and larger brains. Their hands and arms continued to evolve and develop.
Analogous Traits
Works Cited
"Anthropoids." Eskeletons. N.p., n.d. Web. 21 Feb. 2013. <http://www.eskeletons.org/treecat.html>.
"Using Homologies to Reconstruct Relationships." Using Homologies to Reconstruct Relationships. N.p., n.d. Web. 21 Feb. 2013. <http://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_hs_11>.
This was one of the most interesting posts I saw out of the entire class. I enjoyed how you used what you learned from the textbook as well as outside sources. You made really interesting points and had great evidence and pictures to back it up. I liked the traits you chose for both homologous and analogous traits. Great Job!
ReplyDeleteThanks :)
DeleteHi Kaitlyn, I'm Jessica.
ReplyDeleteI thought your choice of species was a little obvious. You could have gone with species that where harder to compare. But the way you explained everything was very informational and I thought you did a really good job. Primates and humans where my first thought to do on homologous traits, but than I changed mine to fish. And that's what brought me to doing sharks and dolphins. I thought the way you explained the analogous traits was very informational. I explained mine differently, but came up with the same conclusions.
Jessica,
ReplyDeleteThanks for your input. I found it interesting to do the homologous comparison in relation to primates and humans, since this class is anthropology and goes into the depth of evolution in relation to the cultural and biological aspects of humans. What would have been a harder one to compare? How many mammals have the similar forearm bones? Wings on birds? I am not really sure what would have been harder to compare?
Excellent comparison between the thumbs of humans and chimpanzees. Great discussion of ancestry and good description of the structural/functional differences that make these thumbs homologs.
ReplyDeleteWell done as well on the analogous traits. You do a great job of explaining the ancestry and the origins of the two traits to demonstrate the independent parallel evolution that produced them. Great post.
I really loved your comparisons, and the explanations were great and easy to understand too! I didn't even think about using humans and monkeys for homologous, but I like that you focused on just one aspect of them rather than a human and a monkey as a whole. I actually used sharks and dolphins as my analogous example too, but yours is much better explained. Well done :)
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