[human leg]
1. For your homologus traits provide the following information
a. Briefly describe the two different species that possess the homologus trait.
The internal workings of the ear, including the stapes, malleus and incus are homologus to the parts in the jaw of a fish and the arches of their gills.
b. Describe the homologus trait of each species, focusing on the differences in structure and
function of the trait. Why do these homologus traits exhibit differences between the two
species? Make sure your explanation is clear and complete.
The bones in mammals ears are small, they all descend from a single bone that was part of the jaw called the hoymadibular bone. This bone is the same bone that forms the jaw of fish. This bone is homologus to mammals and fish but developed in different ways because of different needs of the species.
c. Who was (generally, not specifically) the common ancestor of these two species and how do you know that ancestor possessed this homologus trait?
Both mammals and fish descended from tetrapods.
d. Provide an image of each species in this comparison.
[above]
2. For your analogous traits provide the following information (25 pts):
a. Briefly describe the two different species that possess the analogous trait. (5 pts)
Insects and Mammals both have legs, but they are from different origins and for different reasons.
b. Describe the analogous trait of each species, focusing on the similarities in structure and
function of the trait. Clearly explain why these analogous traits exhibit similarities between the
two species.
The legs of insects are jointed leg segments called podomeres. The legs of Mammals are bones that are jointed with ligaments and rotate in sockets.
c. All pairs of organisms share some common ancestor if you go back far enough in time. Did the common ancestor of these two species possess this analogous trait? Why or why not?
The common ancestor of these two species must have had legs, because they both obviously have legs.
d. Provide an image of each species in this comparison.
[above]
Hello Sierra Anne,
ReplyDeleteVery interesting for what you have chosen for the homologus and analogous traits. Its crazy how the hoymadibular bone in the mammals ear is the same bone that forms the jaw of a fish but developed in different ways. This is an excellent post and it describes the homologus and analogous traits. Great work!
Hey Sierre,
ReplyDeleteAwesome job. I would of never thought my leg would be similar to a insect. It makes sense after I read this post, but wow and crazy at the same time. hahaha... I wont lie. I laughed when I read this, "The common ancestor of these two species must have had legs, because they both obviously have legs." This a true fact hahaha....I wont disagree with you on that hahaha....
RE: Your homologous traits, that is a very interesting pairing. I'm glad you wrote on this set of traits as many don't realize the relationship between them. A couple of cautions: I think you meant "hyomandibular" and fish did not arise from tetrapods. Tetrapods arose from fish! The common ancestor of these two groups was the group of bony fish.
ReplyDeleteRE: Analogous traits... Why is it obvious that the ancestor must have had legs? The definition of analogous traits is that it is a shared trait that did not arise from descent from a common ancestor, meaning that the ancestor did NOT have the trait (or at the very least, that is not where the two modern species did not inherit them from the ancestor).
Otherwise two very good trait sets. Just make sure you understand the descent principles of the analogous traits.
I picked the same things for my analogous traits. I would not have thought that human legs would be similar to an insects, but after looking into it and researching, I was quite surprised. Also, your information between the mammals ear and fishes jaw bone, is a very interesting point. I learned a lot from this assignment.
ReplyDelete