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Allopatric and Sympatric Speciation exam Flashcards

Allopatric and Sympatric Speciation exam
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  • Allopatric Speciation
    Speciation that occurs when populations evolve in different geographic areas, leading to reproductive isolation.
  • Sympatric Speciation
    Speciation that occurs within the same geographic area, often through mechanisms like polyploidy or disruptive selection.
  • Dispersal
    The movement of individuals from one place to another, leading to geographic isolation and potentially allopatric speciation.
  • Vicariance
    The physical splitting of a habitat, resulting in geographic isolation and potentially allopatric speciation.
  • Polyploidy
    A condition in which an organism has more than two complete sets of chromosomes, often leading to sympatric speciation.
  • Disruptive Selection
    Selection for divergent phenotypes within a population, which can lead to sympatric speciation if accompanied by reproductive isolation.
  • Reproductive Isolation
    A state in which two populations can no longer interbreed, leading to the formation of new species.
  • What is the main difference between allopatric and sympatric speciation?
    Allopatric speciation occurs in different geographic areas, while sympatric speciation occurs in the same geographic area.
  • What role does mate choice play in sympatric speciation?
    Mate choice can lead to reproductive isolation within the same geographic area, contributing to sympatric speciation.
  • Founder Effect
    A reduction in genetic diversity that occurs when a small population colonizes a new habitat, often seen in dispersal events.
  • What is autopolyploidy?
    A type of polyploidy that occurs within a single species due to a cell division error, resulting in extra sets of chromosomes.
  • What is allopolyploidy?
    A type of polyploidy that occurs through hybridization between two species followed by a cell division error.
  • How does vicariance lead to speciation?
    Vicariance physically splits a habitat, leading to geographic and genetic isolation, which can result in speciation.
  • What is the significance of genetic isolation in speciation?
    Genetic isolation prevents gene flow between populations, allowing them to evolve independently and potentially form new species.
  • How can polyploidy create a new species in a single generation?
    Polyploidy results in extra sets of chromosomes, causing reproductive isolation from the original population and forming a new species.
  • What is the role of microhabitat niches in sympatric speciation?
    Microhabitat niches can lead to reproductive isolation within the same geographic area, contributing to sympatric speciation.
  • What is the difference between dispersal and vicariance?
    Dispersal involves movement to a new habitat, while vicariance involves the physical splitting of an existing habitat.
  • How does disruptive selection contribute to sympatric speciation?
    Disruptive selection favors divergent phenotypes, and if accompanied by reproductive isolation, it can lead to sympatric speciation.
  • What is habitual isolation?
    A form of reproductive isolation where populations reproduce in different habitats, often leading to allopatric speciation.
  • Why is sympatric speciation less common than allopatric speciation?
    Sympatric speciation is less common because it is harder to achieve reproductive isolation within the same geographic area.
  • What is the significance of gene flow in speciation?
    Gene flow between populations can prevent speciation by keeping the populations genetically similar.
  • How does self-fertilization facilitate polyploidy in plants?
    Self-fertilization allows polyploid plants to reproduce even when they have extra sets of chromosomes, leading to new species.
  • What is the role of a cell division error in polyploidy?
    A cell division error can double the number of chromosomes, leading to polyploidy and potentially new species.
  • How does hybridization contribute to allopolyploidy?
    Hybridization between two species followed by a cell division error can result in an allopolyploid organism with extra sets of chromosomes.
  • What is the outcome of a vicarious event in speciation?
    A vicarious event leads to geographic and genetic isolation, allowing populations to evolve independently and potentially form new species.
  • How does the founder effect influence genetic diversity?
    The founder effect reduces genetic diversity in a new population, which can lead to rapid evolutionary changes.
  • What is the importance of reproductive isolation in speciation?
    Reproductive isolation is crucial for speciation as it prevents interbreeding and allows populations to evolve independently.
  • How can mate choice lead to reproductive isolation?
    Mate choice can result in individuals preferring to mate with similar phenotypes, leading to reproductive isolation and speciation.