1.
The two different species I chose that had common Homologous traits, are humans
arm and the flipper of a whale.
Some Homologous traits between the two would be the Humerus and
neck bone (seven). A giant whale has the very same amount of neck bones as
humans (seven). Another commonality is the large upper arm bone in the whale,
which would be the humerus in humans. Much of their differences in their
anatomy are due to divergent evolution.
They came from a common ancestor, placental mammals, named
for the placenta that nourishes the fetus during development.
2. The Two different species that had similar Analogous
traits are humans and an insect.
The analogous trait that they have in common is their eyes.
They both have lenses and light sensitive cells that help their eyes to collect
data that a brain can form into an image of their surroundings. The difference
would be a human just has one single large lens per eye, as for an insect
compound eye have many tiny lenses with one lens per ommatidium.
They're no common ancestors between humans and insects, due to convergent evolution, which makes it impossible for these two to have common ancestors.
A little short on information, particularly in Part A, which asked you to "describe" and not just identify your organisms.
ReplyDeleteYou have focused on the commonalities of humans and whale anatomies, but what you needed to explain were the differences in structures that arose from common descent.
"Much of their differences in their anatomy are due to divergent evolution. "
Yes... but that is what you needed to describe! Divergent evolution is the process by which homologous traits arise. What homolgous traits do you see in humans and whales? The structure of the forelimb is a common example. but you can also use the residual hind limbs and compare them to human legs.
Yes, whales and humans arose from a common mammalian ancestor but you needed to discuss this ancestry in terms of a homologous trait to demonstrate that the two species inherited the general structure from that common ancestor.
Good choice of analogous traits.
As stated in the guidelines, all organisms share some degree of genetic relatedness, meaning all organisms share a common ancestor if you go back far enough. The question is, did the trait in question arise from the common ancestor or evolve independently from convergent evolution. In this case, we do know that the complex insect eye and the human eye arose independently from each other and are good examples of analogous traits.