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13 Cards in this Set

  • Front
  • Back
List 2 hypotheses of speciation
1. Resources are limited
2. The competitive exclusion principle
What are the resource of speciation?
resources necessary for reproductive success

food, nest sites, shelter, water etc.
What is the competitive exclusion principle?
2 species with identical resource requirements cannot coexist. In nature, an individual's most serious competitors are likely to be conspecifics.
Speciation is thought to involve differential evolution in seperate populataions.
In sympatric populations(occupying the same geographic area), __________ would prevent genetic differentiation.
Sympatric speciation my be possible through ___________.
Behavioral isolation
What is Allopatric speciation?
involves geographically isolated subpopulaions which experience different selective regimes and consequently diverge.
In Allopatric speciation, non-random vs. random mating will depend on?
the fitness of F1 offspring
Selection will favor non-random mating if hybrid offspring have low or high fitness? and how this can occur sympatrically

as long as the populations are reproductively isolated
What are the 2 outcomes after the removal of geographical barrier or expansi0n of subpopulations?
1. Random mating - merging of character (use same resources)
2. Non-random mating -further differentiation (less overlapping resources, AA' = AB)
What are the 2 roles of BEHAVIOR?
1. Isolating mechanisms
2. Niche separation
reduce the probability of hybridization

Many if fnot most are behavioral (courship displays etc)
Describe Niche Separation
An isolating 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)