Homologus
The bat, a human, a mole, a tree screw, a wolf, a sea lion, and an elephant all evolved from a common ancestor,and they share common anatomical traits.As we can see in these comparisons the forelimbs of the bat, a human, a mole, a tree screw, a wolf, a sea lion, and an elephant, the limbs look different on the outside and though they vary in function, they are very similar in skeletal structure. More significantly, they are from the same structures when in the embryo. Structures that are embryologically similar, but have different functions, are called homologous structures. Though these animals look different, a comparison of homologous structures indicates that they are similar. In fact This suggests that these animals evolved from a common ancestor.
Analogous
For analogous traits I chose to use the example of a human eye and an octopus eye. Both humans and octopuses evolved what is referred to as camera eyes. Its called camera eye because it consists of a lens projecting an image onto a retina. The common ancestor of the octopus and of man possessed this analogous trait and adapted it so it could see.
It was interesting that you chose the eyes of humans and octopus eye. It was interesting to learn that they both have the same label known as the camera eye. The use of many species you listed under homologous traits was interesting as well. You did your research well. Great post.
ReplyDeleteit is so boggling to compare all of these different species and find that they have similar limb structures. even though we are all unique it seems like everything has some similarities. i mean you would never think about comparing an elephant and a human. or even comparing a human eye and an octopus eye. with out this class i would never of known any of this.
ReplyDeleteExcellent work on your homologus traits. Loved the comparison of the fore-limbs across all of those organisms. But can you guess what type of creature was the common ancestor? Mammal? Reptile? Amphibian?
ReplyDeleteRe: the human and octopus eye as an analogous structure. If their common ancestor possessed the trait, that would mean that the eye was NOT analogous, it would be homologous because both inherited their eyes from a common ancestor. To be analogous, the structures must evolve their traits independently through parallel evolution. So... does the octopus and the human have a common ancestor who possessed the eye structure or did it have no eyes? That is the question you need to answer here.