a) The two different species that possess the homologous trait is the ground squirrel and the macaw because they both are vegetarian and only eat plants and plant extracts to survive.
b) Macaws have breaks and generally live in the forests or rain forests where they eat plants and plant extracts. Ground squirrels live on the ground not the trees and are considered varmints because the ruin crops and they also eat a variety of seeds which is similar to the macaw as they are both vegetarians.
c) The common ancestors to these two species were both ground mammals and after researching on them both even their ancestors had vegetarian appetites to survive.
d)
2. For your analogous traits provide the following information
a) The two different species that possess the analogous traits are the turtle and the snail because they both have shells to protect them from the outside world and predators.
b) The turtle has a protective shell as does the snail. They are both slow which the shell provides protection for this and predators. The turtles shell in some cases are hard as bone and made of bone where as the snail needs their shell other than protection because they have no bones at all.
c) No the ancestor would not have the train of the protective shell and the species is reptile would is more commonly equipped with other protections rather than a shell. And the ancestors of snails don't all have protective shells at all.
d)
That is a good one for your homologus trait. I for some reason didn't think of food differences. Same with the similarities between the shell. Both very good and different answers. Very unique to most of what I was researching about.
ReplyDeleteGood question.. what do you think? Perhaps not if it increased the weight, but what if the weight stayed the same but the composition itself became less breakable? A different shape? Different chemical composition? Lots of natural possibilities, but evolution will only do so if the benefits outweigh the costs.
ReplyDeleteOkay on the opening description of your homologous species pairings but the wording is confusing. Are they homologous because they are vegetarian? Or because of the function and ancestry of the traits?
ReplyDeleteVegetarian diet patterns can be inherited but not necessarily, and in this case, given the species you are comparing are so distant genetically from each other, it is not likely at all that vegetarian diets are homologous traits, and it would be very difficult to demonstrate that it is.
When we talk about analogous and homologous traits, we are usually talking about physical traits that can be fossilized or traced through anatomy or genetic lines. That isn't the case here. And in the case of homology, we need to identify the *structural differences* in traits and explain them in terms of their functional differences. We can't do that here, partially because you aren't describing differences, only similarities.
With regard to ancestry, mammals are not the ancestors of birds. The common ancestors of both of these organisms would be archaic reptiles... who are not vegetarians.
I would take a look at other student posts to get an idea of examples of homology.
Good images.
Good choice for analogous traits and good descriptions of the traits themselves and their functional differences.
In the issue of ancestry, are you arguing that the common ancestor is a reptile? We would have to go back much farther to find a common ancestor for these two species, but do we need to do that to confirm analogy? We know quite a bit about turtle evolution, enough to know that the shell is a derived trait unique to turtle and tortoise in the reptile group. This indicates that the shell trait arose during the evolution of turtles, from within the class of reptiles, long after the line that led to turtles split from the common ancestor with snails. That means this trait evolved independently from that common ancestor. That is what we need to know to confirm analogy.
Good images.
I like your take on the shells of different animals. I would have never though of that kind of jump.
ReplyDeleteBut, with your homologous traits you may want to rethink the concepts. Homologous traits are something physical that we can trace back through physical evidence. Vegetarianism is not something we can necessarily trace back through physical means.