Chapter 17 - Speciation Flashcards
What is the concept of biological species?
Groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.
What mechanism is Pre-Mating?
Prevents mating attempts. For example, geography. You can’t mate if you can’t meet.
What mechanism is Pre-Mating?
Prevents mating attempts. For example, geography. You can’t mate if you can’t meet.
Ecology:
Different populations use different resources.
Temporal:
Different populations are unable to mate due to time/season.
Behavioral:
Different groups use different displays and courtship to attract a mate.
Mechanical:
Reproductive organs are not compatible (such as a great Dane to a chihuahua).
Posting-Mating Mechanisms:
Mating occurs but is not viable.
Gametic Incompatibility:
Mating occurs but fertilization does not.
Hybrid Inviability:
Hybrids do not survive, or is less successful than the parent.
Hybrid Infertility:
Hybrids are infertile.
Speciation Depends on Two Things:
Population Isolation and Genetic Divergence
Population Isolation:
Prevents gene (allele) flow between two groups
Genetic Divergence:
Development of large genetic differences.
By Chance=
Genetic Drift
Natural Selection=
Different environmental pressures
Allopatric Speciation:
Two populations are geographically separated. Invasion of new habitat.
Habitat Division:
Geographic, Climate, or Landscape Change separates populations.
Sympatric Speciation:
population isolation without geographic separation. ecological niche differences separate and stop gene flow
Mutation:
Rare but can lead to instant speciation
Adaptive Radiation:
Many speciation events in a short time. Populations invade a variety of new habitats (Darwin’s finches in Galapagos)
What are some ways to become extinct?
Localized Distribution
Overspecialization
Species Interaction: Competition + Predation
Localized Distribution:
Species only found in a very small area.
Overspecialization
Can only survive/reproduce in limited environment
