Two different species that posses the homologous trait are humans and cats. Both bone structures of the arms look very similar.
Looking at the arm bone structure of a cat vs. a human, it looks like cats have a radius and ulna. Cats even have phalanges in their paws, just like humans have in their hands. They are both looking very similar, but they are both used differently. Cats have the ability to jump very high, they use their front paws to land properly on their feet. With humans, we can't land so hard on our hands- something will break. The bone structure of cats allow them to land, there will be immense pressure when doing so- humans cannot handle that kind of pressure on their arms.
The last common ancestor of humans and cats is the Juramaia Sinensis. A recent fossil of this animal showed a good part of its arm- I saw phalanges and two bones what seemed to look like a radius and ulna.
Not only are cats and humans similar to one another, they share that same similarity with bats, horses, birds, and whales.
Analogous Traits:
Dolphins and sharks share numerous traits- however they are very far related. They are analogous because they both have fins in the same exact spots so they can swim in their environment.
The color of dolphins and sharks are very similar- they are this color so it is easy to blend in with things in the ocean. Sharks and dolphins share the same structure of where the fins are located. They both use their fins to swim. However, they are both completely different species, sharks are fish and dolphins are mammals.
Dolphins and sharks aren't really that similar but they are both analogous. They don't necessarily share a common ancestor, but they both have similarities to animals that are currently in the ocean today. We know they are analogous because other species in their environment share the same dorsal fins and structures like all the other types of fish out there.They get their dorsal fins and similar structures from convergent evolution.
The opening section in both the homologous and analogous areas asked for a description of your species, not just identification. This would help your reader understand the environment and behavior of the species to better understand why their traits evolved the way they did. Needed to be expanded.
ReplyDeleteI appreciate the discussion of different functions between the cat and human forelimb, but how is this reflected in the structure itself?
Good discussion on ancestry, but how can we use that information to support your contention that these are homologous traits?
Good images.
For your analogous traits, you start with fins, then you move to color, then back to fins. Don't distract your reader by wandering off on a tangent.
"Dolphins and sharks aren't really that similar but they are both analogous. "
Species can't be analogous. Only their traits can, so how does this confirm that these traits are not the product of common descent?
Let's clarify the issue of ancestry here: The common ancestor of the dolphin and shark is an archaic fish, who did possess these fin structures and also passed that trait onto extant shark species. Based upon that information alone, it is still possible that these traits are genetically related. So the question is, did the dolphin also inherit it's fin from that common ancestor? Dolphins "fins" evolved after dolphins split off from terrestrial mammals, i.e., long after the split with ancient fish. This provides us with the evidence we need to confirm that this trait did evolve independently in at least one of these organisms, making these traits analogous.
Good images.
I liked your comparison on sharks and dolphins. The similarities of sharks and dolphins have never crossed my mind. I enjoy the detail you provided in your post, about the sharks/dolphins using their color to blend in with their surroundings. Survival wise that is a good trait to have, so one can keep themselves hidden from a predator or prey on their next meal. If I wasn't in this class, by looking at a shark/dolphin I would think that they are related somehow.
ReplyDeleteI enjoyed reading your blog. I learned a lot and I never though about the similarities between cats and humans. It was a very interesting approach to this assignment. Your comparisons between sharks and dolphins are very accurate and I never knew a dolphin was considered a mammal.
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