1.
1.
Dolphins and whales are two
different mammals however they both have similarities to one another. One similarity
that they share are flippers, flat tails, blow holes, and warm blooded. The
flippers of dolphins and whales are a homologous trait. Both share a common
ancestor that came from the delphinidae family and According to fossils
dating back about 50 million years, whales even share a common ancestor with
the land-dwelling hipopotomus (Dolphin vs. Whale). Humans as well share a common
ancestor with dolphins and whales which has been dated back to the cretaceous. The
homologous trait would be the flippers and the arm of a human.
2.
1.
Dolphins
and sharks look very similar to one another by size, color, fins, both are
animals of the ocean and can be mistaken as one another if they are only viewed
partially. These two are analogous to one another because although they are
very similar a shark is considered a fish and a dolphin is considered a mammal.
"Dolphin vs Whale." -
Difference and Comparison. N.p., n.d. Web. 22 June 2015.
Good description of the similarities between your homologus creatures, however the assignment asked for us to describe the differences between the two in accordance to that trait. For instance, you might have wanted to expain the difference of the "flippers, flat tails, and blow holes". Although the picture is helpful, I don't really understand why the birds wing and human arm are there. Perhaphs a picture of a fin of a dolphin vs. a fin of a whale would have been more appropriate.
ReplyDeleteI agree with your statement on dolphins and sharks looking similar to one another in the ocean. I like how you described the analogous trait, however, I believe you were supposed to mention a general common ancestor for the two analogous creatures.
Thank you.
You start off your homologous section comparing whales and dolphin limbs. Unfortunately, these are just common shared traits, without the structural/functional differences necessary for homologous status. Then at the end, you switch to a comparison with humans. That would have been a better comparison but it wasn't part of your discussion for Part B.
ReplyDeleteYes, humans share a common ancestry with dolphins and whales, but all organisms share ancestry with all other organisms if you go back far enough in time. What we need to know is whether or not that common ancestor possessed this common archaic limb structure. Since all organisms are mammals, that ancestor was also mammalian and possessed the archaic mammalian limb structure, passing it onto these modern descendents.
A little short on information for your analogous traits. Species cannot be analogous to one another. You can only talk about their traits being analogous. Which traits were you comparing here? And having two distantly related species doesn't guarantee that traits are analogous. Our middle ear bones are actually homologous to the cartilagenous gill arches in early fish. Seriously! So just because organisms are very far apart on the evolutionary tree doesn't meant their traits are analogous. In this case the common ancestor of the shark and dolphin was an early fish, much like a shark. So the shark did inherit its traits from that early fish ancestor. So are this homologous? We need to know where the dolphin inherited it's traits to confirm that these are analogous. Without knowing which traits you were comparing, it is difficult to discuss this.
Good images.
Great choice on the homologous because I had the same idea with the human and bats forearm. I'm not sure if you did the analogous right. Great choice of using the dolphin and human arm. Are you also comparing it with whale too?
ReplyDelete