Term
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Definition
| A group of organisms that maintains a distinctive set of attributes in nature. |
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Term
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Definition
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Term
| Describe the discuss characteristics used to define species. |
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Definition
Speciation- The formation of new species,Occurs when two populations change in their heritable traits to the point that breeding between them no longer takes place.
Most commonly used characteristics to identify species:
morphological traits- Physical traits
ability to interbreed
molecular features
ecological factors
evolutionary relationships |
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Term
| Describe reproductive isolation. |
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Definition
Prevents one species from successfully interbreeding with
other species. |
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Term
| Distinguish among the different types of pre & post-zygotic barriers |
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Definition
Two categories of reproductive isolation mechanisms
Prezygote- Prevent the formation of a zygote
postztgote- Block the development of a viable and fertile individual after
fertilization has taken place. |
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Term
| Explain the mechanisms of speciation |
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Definition
Underlying cause of speciation is the accumulation of genetic changes in a population that make it different
from the species from which it was derived. |
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Term
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Definition
Division of a population into 2 or more species.
Requires gene flow between populations to be interrupted |
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Term
| Define allopatric speciation |
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Definition
Most prevalent method for cladogenesis. Occurs when some members of a species become
geographically separated from the other members.Allopatric speciation can also occur when a small
population moves to a new
location that is geographically separated from the main population |
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Term
| Define Sympatric speciation |
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Definition
Occurs when members of a species that are within the same range diverge into two or more different species
even though there are no physical barriers to interbreeding. |
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Term
| Define gradualism equilibrium |
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Definition
| Each new species evolves continuously over long spans of time. Large phenotypic differences that produce new species are due to the accumulation of many small genetic changes. |
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Term
| Define punctuated equilibrium |
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Definition
| Species in equilibrium for long periods and then short rapid bursts of changes. |
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