1. A
– Two different species that possess a homologous trait are human and bats.
B – The trait that these
two species share are their front limbs. However, each species use their limbs differently. The humans
use theirs for picking up objects, eating, and having the sense of feel, while
the bats use theirs to fly. The reason for the differences in this trait though
are because differences
in the environment, resulting in different functions and evolutionary selection
pressures which is also called divergent evolution. C – Both humans and bats are in the class Mamalia, which is reason enough to suggest that they come from a common ancestor.
1. A – Two different species that
possess an analogous trait are owls and butterflies.
B – The trait these two species share are their wings. The
structure for the owls wings are covered in feathers while the butterflies are
in scales, each use them to fly. The main similarity is that they both have
wings and use them daily to fly. C – If you were to go back in time you wouldn’t be able to find a common ancestor between the two because the trait is analogous and not homologous. Insects have two pairs of wings while birds have one, and insects lack bones while birds do not. Since the wings have evolved independently in each of these groups and do not show that they are closely related means that the wings trait between the two is analogous with no common ancestor.
Jorge,
ReplyDeleteI too for this assignment looked at using the owl and a butterfly. I found it to be quite interesting to see how the animals are so similar yet so different. I like your explanation about how it evolved interdependently.
Part A of each section asked for a description of each organism, not just identification.
ReplyDeleteHow do the different structures help with the different functions? You have identified the functions but haven't explained how the structures are adaptations for those functions.
Yes, both humans and bats are mammals, but that doesn't address the issue of whether or not this trait arose from common descent or not. Did that common mammalian ancestor possess the generalized limb structure and pass it on to the two descendents?
Good discussion of the analogous trait.
"If you were to go back in time you wouldn’t be able to find a common ancestor between the two because the trait is analogous and not homologous. "
That isn't what analogous or homologous mean. All organisms share at least some genetic similarities with all other organisms, which means that they are all related in some way, even if you have to go back very far in our evolutionary history. So this doesn't address the question regarding ancestry. We need to know if either or both of these organisms developed this trait independent of the common ancestor. Insect evolution is not very well known, but we do know that birds developed their wings when they split off from reptiles. That means birds, like owls, evolved their wings independently from that common ancestor with insects much farther back in earth's history. That confirms these traits are analogous.
Good images.