Study Questions 1-3

Study Questions 1-3 - Thread:Question 1...

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Thread: Question 1 Post: RE:RE:RE:RE:Question 1 Author: David Schultz Date: Monday, February 19, 2007 Status: Published Overall rating: Not rated OK, but with one correction: Your statemnt: "A paraphyletic group is a group that is monophyletic except that some descendants of the common ancestor have been placed in other taxa" is technically not true. You might say that a paraphyletic group includes just some of the descendants of a common ancestor, but not all. Total grade: 5 Thread: Question 1 Post: RE:RE:RE:Question 1 Author: Jaime Reuter Date: Friday, February 16, 2007 Status: Published Overall rating: Not rated Im sorry, when i began looking the question up in the book i saw polyphyletic right after monophyletic on pg. 45 and assumed that the question was asking about polyphyletic.Im sorry about the misunderstanding. A monophyletic group is defined as being a group that includes all of the descendants of a single common ancestor. Examples of this type of group would be the birds, and the beetles. Both the birds and beetles are said to have come from a single common ancestor and are therefore characterized together as a monophyletic group. A paraphyletic group is a group that is monophyletic except that some descendants of the common ancestor have been placed in other taxa. Paraphyletic taxa usually lack species that have been placed in another taxon in order to emphasize their distinctive adaptations. For example, the traditional family Pongidae consists of orangutans, gorillas, and chimpanzees; the family is paraphyletic, because humans- the closest relatives of the chimpanzees- have been placed not in the Pongidae, but in the Hominidae. Another example of a paraphyletic group is birds being placed in the class Aves while dinosaurs and crocodiles are placed in the class Reptilia, then "Reptilia" is paraphyletic. The class Aves is a monophyletic group.
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Thread: Question 1 Post: RE:RE:Question 1 Author: David Schultz Date: Friday, February 16, 2007 Status: Published Overall rating: Not rated The question is about paraphyletic groups, not polyphyletic groups. Grade: 1 Thread: Question 1 Post: RE:Question 1 Author: Jaime Reuter Date: Thursday, February 15, 2007 Status: Published Overall rating: Not rated A monophyletic group is defined as being a group that includes all of the descendants of a single common ancestor. Examples of this type of group would be the birds, and the beetles. Both the birds and beetles are said to have come from a single common ancestor and are therefore characterized together as a monophyletic group. A polyphyletic group includes unrelated lineages that are more closely related to species that are placed in other taxa. An example of a polyphyletic group would be whales with fishes, since whales stem from ancestors that fish do not share, like the earliest tertapod and the earliest mammal. Thread:
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This note was uploaded on 04/21/2008 for the course BIOL 370 taught by Professor Schultz during the Spring '07 term at Nicholls State.

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Study Questions 1-3 - Thread:Question 1...

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