Humans and bats share similarities in the forelimb bone structure. The bones in the hand are elongated into five fingers in the human and five claws in the bats. Although these two held the same trait, they use them for completely different purposes. Humans can do many things with their fingers while bats are limited to grabbing food or holding onto a tree. The common ancestor was a stem reptile because they held the trait. They have developed over years and their similarities are product of separate evolutionary processes.
Analogous Traits
Birds and butterflies both have wings that are used for flying, however their structure is completely different. These two are completely different species, one is an insect and one is a bird. Butterfly wings are made of skin and bones. Bird wings are made of muscle, bones, and feathers. Although they appear to be related due to wings, they only have a very remote ancestor. Birds evolved from reptiles, who had no wings, while the butterfly evolved from arthropod, with no wings.
Good comparison of structural differences between human and bat forelimbs. You discuss the environmental stress that led to the human hand but what about the bat? Since both species are mammal, the likely ancestor was also mammal, so no need to go back to the reptile, but you are correct that both species inherited the base trait from that ancestor.
ReplyDeleteOne question: Are butterfly wings made of "skin and bones"?
Great discussion on the ancestry of the bird and how that demonstrates that the bird wing arose independently from the butterfly wing. The butterfly may indeed have evolved from other winged ancestors, but because the trait arose separately in the bird, these are analogous traits.
Excellent Post! I too used the Human arm but I compared it to the birds wing, using the similar bone structure as the homologous trait. I found that the common ancestor the Tetrapod was very interesting, also to think that from one reptilian ancestor you can get a bird/bat and a human! Very strange!
ReplyDeleteI also like your analogous example as well!
You also get the Best Picture award too!