Chapter 17 - Speciation Flashcards
(25 cards)
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
