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13 Cards in this Set
- Front
- Back
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List 2 hypotheses of speciation
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1. Resources are limited
2. The competitive exclusion principle |
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What are the resource of speciation?
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resources necessary for reproductive success
food, nest sites, shelter, water etc. |
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What is the competitive exclusion principle?
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2 species with identical resource requirements cannot coexist. In nature, an individual's most serious competitors are likely to be conspecifics.
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True/False
Speciation is thought to involve differential evolution in seperate populataions. |
True
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In sympatric populations(occupying the same geographic area), __________ would prevent genetic differentiation.
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inbreeding
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Sympatric speciation my be possible through ___________.
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Behavioral isolation
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What is Allopatric speciation?
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involves geographically isolated subpopulaions which experience different selective regimes and consequently diverge.
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In Allopatric speciation, non-random vs. random mating will depend on?
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the fitness of F1 offspring
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Selection will favor non-random mating if hybrid offspring have low or high fitness? and how this can occur sympatrically
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Low
as long as the populations are reproductively isolated |
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What are the 2 outcomes after the removal of geographical barrier or expansi0n of subpopulations?
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1. Random mating - merging of character (use same resources)
2. Non-random mating -further differentiation (less overlapping resources, AA' = AB) |
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What are the 2 roles of BEHAVIOR?
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1. Isolating mechanisms
2. Niche separation |
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Describe ISOLATING MECHANISMS
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reduce the probability of hybridization
Many if fnot most are behavioral (courship displays etc) |
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Describe Niche Separation
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An isolating mech.by itself does NOT resolve competition.
-many species use morphological specialization to separate in niche (body size, tooth or bill size, etc) -Also behavioral niche separation (EXTREMELY IMPORTANT) |
