Since the large beaked birds are more efficient at cracking the hard seeds and

Since the large beaked birds are more efficient at

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Cameroon whose members display two distinctly different beak sizes. Since the large beaked birds are more efficient at cracking the hard seeds and the small beaked birds are better with the soft seeds, birds with normal sized beaks are somewhat inefficient at cracking either sized seeds. Finally, stabilizing selection acts against both extremes and favors the intermediate (note that this selection is the opposite of disruptive selection). An example of this can be seen in human baby sizes. Most babies average a healthy 6-8 pounds, since anything too far above or below can lead to an increase in mortality rates. 3. A species can be described by a group of interbreeding natural populations which are reproductively isolated from other groups, or more specifically, different species. This reproductive isolation between groups sets up “barriers” which effectively isolate a species’ gene pool. These barriers can be categorized into two separate groups: Prezygotic barriers, which block fertilization from occurring, and Postzygotic barriers, which may contribute to reproductive isolation after the hybrid gamete is formed. A
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couple examples of prezygotic barriers could be habitat isolation, temporal isolation, and behavioral isolation. Habitat isolation describes two species living in the same
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