1. Homologous - Human & Whale
The human and whale both share a common ancestry trait such as the structure of limbs in the vertebrate. Humans as we know, live on land, while whales dwell in the depths of the seas. The limbs on the whale and human are built on the same structure, but are switched around in different areas to support the living environment they're selected into. A common ancestor from a whale and human would be the Ambulocetus, which also had a similar structure of limbs. There is no analogous similarity
between a whales fin and a humans hand due to the different uses of them, but the similar structure of the limbs and vertebrae is what makes humans and whales homologous.
2. Analogous - Owl and Butterfly
The Owl and Butterfly however do not share an ancestry trait, but they both are given wings to be able to fly. The anatomy of an owl's wings are structured into the bird family and leans towards the ancestry of humans because how the limbs are formed. The structure of a butterflies wings are different than an owls anatomy, but share the same flying ability as the owl as well. The ancestor of the owl is the Archaeopteryx and the ancestor of the butterfly is the Longhorn Caddis. Both ancestors were gifted with flight, giving these two an analogous trait still.
Jordan,
ReplyDeleteYour post was quite interesting. It never really occurred to me that humans and whales came from common ancestors although I knew we are all mammals. Good job.
Tiffany
Careful of the use of the word "analogous" in your first section. It means something specific for this assignment.
ReplyDeleteYou are correct that the limbs of whales and humans are homologous traits. More details would have been helpful. How do the different structures help in their environments, specifically?
Ambulocetus was already a marine creature, which means it existed after the move from land to water. It could be ancestral to whales but not to humans, making it impossible for it to be a common ancestor. It wasn't necessary to identify a specific common ancestor, just an understanding that the ancestor possessed that limb structure an passed it onto these two descendents, making the structures homologous.
For your analogous trait, the wings of these two organisms are indeed analogous and good description of the development of these traits to serve a common purpose. Regarding ancestry, remember that we need to demonstrate that these traits evolved as a result of parallel (or convergent) evolution, not from common ancestry. So how do we know that the common ancestor of both of these species did not possess wings and pass them onto these descendents? Again, you didn't need to identify a specific common ancestor. What do we know about the evolution of the bird wing that helps us answer this question? Did all of the ancestors of the bird possess wings? Think prior to Archeopteryx...
Hi Jordan,
ReplyDeleteyou did a great job on your post, I really enjoyed it. I did not consider the fact that we have the same structure of limb in our vertebrate even though we are both mammals. I always just compared humans to non human primates.
Hi Jordan, I actually really enjoyed your post. I had no idea that humans and whales had anything in common. Another thing I found interesting was the comparison between the owl and butterfly. I liked how you gave details about each's wings. Good job!
ReplyDeleteYour whale picture is so cute. Jordan I liked reading your post. ^_^ Also I believe that whales and humans are both mammals too. :) I also hear that whales are very intelligent.
ReplyDelete