1.
a. Elephant and Beaver are two species that possess homologous traits. These two species may not look the same but their homologus traits have been adapted for different roles.
b. Beaver and Elephant they each use their teeth for different purposes. The beaver uses its teeth for chewing through tree trunks. However, the elephant use its tusks for digging, peeling bark from trees and fighting. Examinations show that each of these traits is a modification of the basic incisor tooth structure. Evolution adapted the elephant and the beaver to perform different functions. These traits are homologous structures, inherited from a common ancestor with incisor teeth.
c. Elephants ancestor was Mammutidae and the Beavers ancestor was the Rodentia.
d.
2.
a. Dolphins and sharks both have a streamlined body shape with a triangular fin on the back and two side fins These two animals may look the same but underneath their skin they are very different.
b. Both dolphins and sharks swim after prey in the ocean. In order to swim faster they use their streamlined bodies and fins. Their streamlined bodies, flippers and dorsal fins are the result of convergent evolution. The analogous structure between the shark and dolphin is the result of the similar challenges and similar adaptations that they have faced throughout life. Nevertheless, having the analogous traits has been advantageous for them.
c. Both Shark and Dolphin are vertebrates. Shark is a type of cartilaginous fish and Dolphin is a Mammal.
d.
1 comment:
Great background on both sets and good examples of homologs and analogs.
The only thing missing is the discussion of the common ancestor, not just the ancestor of each organism.
What type of creature was the common ancestor of the elephant and the beaver? What about the dolphin and the shark? Did the common ancestors possess the specific traits? Why or why not?
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