Humans (mammal) and fish both posess tail bones.
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. (10 pts)
The homologous trait is the tail bone, both have a tail bone however they do not appear the same and are not used for the same purpose. The tail bone of a human is not used for survival or help with every day activities and is usually left unnoticed without moving, whereas the tailbone of a fish serves a purpose to move side to side and help it swim. Humans are evolved enough to not need the help of a tail so it has "dissapeared" however the bone is still there. Fish live in the water and need it to help swim, so they still have a tail.
c. Who was (generally, not specifically) the common ancestor of these two species and how do you know that ancestor possessed this homologus trait? (5 pts) d. Provide an image of each species in this comparison. (5 pts)
An ancient fish was the common ancestor as the bones it possessed were passed on and changed to become elbows,wrists,etc.,as seen in humans and the tail bone was evolved and some bones changed for evolved fish to better fit the environments.
a. Briefly describe the two different species that possess the analogous trait. (5 pts)
Dolphin (mammal) and Shark (fish)
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. (10 pts)
Both are predetory and have fins, they both live in the water and adapted to have fins to help them survive and swim.
c. All pairs of organisms share some common ancestor if you go back far enough in time. Could the common ancestor of these two species have possessed this analogous trait? How do we know these traits are analogous and not genetically related from common descent? (5 pts) d. Provide an image of each species in this comparison. (5 pts)
The dolphin was a land animal that then turned into the dolphin over many years and did not need a fin to survive originally, it was made from adaptation and evolution and that is why a dolphin has a fin like a shark though it's ancestor did not possess fins. The shark was always in the water and never on land.
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Hi Learning Lemur,
ReplyDeleteI enjoyed reading your post. I liked that this example of the homologous trait because it is obviously very relatable. It was also a clear description of the different uses of the tail bone and the evolution of it. The example of the anologous trait of the fin in sharks and dolphins was also clear about its evolution.
The opening prompt for both sections specifically ask for descriptions, not just identifications of your two species. Expand and provide your readers with a better foundation of understanding for these comparisons.
ReplyDeleteHomology: Good choice of traits here, but careful about the assumption that our tailbone no longer functions for us. It still serves as an important muscle attachment for the muscles that support our abdominal cavity and help to control urinary, excretory and reproductive function. We would notice if it wasn't there.
"Humans are evolved enough to not need the help of a tail "
"Evolved enough" for what? A little anthropocentric. Remember that all apes are missing their tails, not just humans, so it is better to actually try to understand why we lost the tail. In honesty, this is still up to debate among primatologists, but it would have been appropriate to include possible explanations here.
I agree that the common ancestor was an archaic fish, but I'm confused as to the mention of bones becoming limbs since we are talking about the tail structure, which isn't related to the limbs.
Analogy: The trait here is fins, not predatory behavior, correct? Can you expand on how the shape and structure of the fin helps in their given environment? A single sentence was not sufficient here.
Very good discussion in your ancestry section. That is precisely the logic needed to demonstrate independent evolution of this trait in at least one of these species.
Good images.