1. a. Whales and Humans share a homologous trait. The bones on the front fins of a whale are homologous to the bones in a human arm.
b. The bones are in different in size and serve slightly different functions depending on the animal. The differences can be easily observed. The structure of the bones are different. Both humans and whales have phalanges, however the sizes of the ulna, radius, and humerus are different. Those three bones are larger in humans than in whales.
c. The legged sea cow is the common ancestor of the whale and human. This ancestor possessed this homologous trait because it was a sea animal that evolved with limbs and went out of the sea to land. Then returned to the sea while containing limbs.
d. Images:
whale
2. a. Dolphins and Sharks posses an analogous trait. This trait is the dorsal fin.
b. The differences of the trait in these species are in 4 different categories; Number, curve, texture, and attachment. Most dolphins have just one dorsal fin, while many shark species have a second. A dolphins fin has a curved silhouette, while most shark fins have a straight forward edge. The fins of dolphins are smooth and firm, while sharks have notched or ragged look to the trailing edge of their dorsal fin. The shark fin is supported by many fibrous strands, unlike dolphin fins. The dolphin fin is smoothly connected to the back of the animal, while the rear edge of the shark fin is slightly detached creating a free tip.
c. Dolphins evolved from an artiodactyl, a land mammal with even number of toes. The closest relative of all the whales and dolphins is the hippo. Hippos do not have fins. No artiodactyl has fins. That means dolphins evolved their fins independently of sharks.
d. Images:
Dolphin
Just so you know your pictures aren't showing up on your blogger. I research a little bit out the whale and the human and your right they do have the same type of bone structure. I noticed for your third animal you used the the first two common ancestor. I though it was suppose to be something different not sure just saying.
ReplyDeleteWith the dolphin and the shark i agree with the dorsal fin. They are both also mammals. The believe the dorsal fin is what helps them swim also.
Well-done.
ReplyDeleteVery interesting how two species that seem to be really different, the whale and the human, are actually share some similarites. On the other hand, two species that one might think have a lot in common, the shark and the dolphin, are really different. Good Job.
ReplyDelete