evolution and speciation

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evolution and speciation
2014-12-21 15:04:31
evolution evolutionOAT
evolution and speciation
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  1. Fitness
    – the ability of an organism to pass on its alleles
  2. Natural Selection
    – differential reproduction of an organism based upon fitness in its environment-the alleles that confer fitness will increase in frequency in the gene pool over time
  3. Stabilizing Selection
    – Selection against the extremes (for the averages)
  4. Disruptive (Divergent) Selection
    – Selection against the averages (for the extremes)
  5. Directional Selection
    – Selection against one extreme (but favoring the opposite extreme)
  6. Artificial Selection
    – directional selection done by humans with selecting for traits in animals and crops
  7. Sexual Selection
    – Differential mating between males and females
  8. Species
    – group of organisms that are capable of interbreeding to produce ‘fit’ offspring
  9. Reproductive Isolation
    – barriers preventing members of different species from producing ‘fit’ offspring
  10. Polymorphism
    – the existence of multiple phenotypes within a population
  11. Adaptation
    an inherited trait that confers greater fitness
  12. Specialization
    – an adaptation to a specific function or environment
  13. Ecological Niche
    • – the sum of the environmental requirements required for a species to persist
    • -includes habitat, predators, prey, etc.; thought of as being unique for each species
  14. Inbreeding
    – increased likelihood of mating between organisms with similar genotypes (limits genetic variation)
  15. Outbreeding
    - increased likelihood of mating between organisms with different genotypes
  16. Genetic Drift
    • – random change in allele frequencies in a population
    • -smaller populations are more susceptible to genetic drift
  17. Bottleneck
    – dramatic decrease in size of a population making it susceptible to genetic drift
  18. Convergent Evolution
    – two species possess the same analogous structures unrelated to a common ancestor
  19. Divergent Evolution
    – divergence leading to distinct populations / species
  20. Parallel Evolution
    – similar evolutionary changes in different species due to similar environmental pressures
  21. Symbiotic Relationships
    • 1) Parasitism
    • 2) Commensalism
    • 3) Mutualism
  22. Parasitism
    – when a species requires another species as a host to live, harming the host in the process
  23. Commensalism
    – an organism requires another species as a host to live with no harm or benefit to the host
  24. Mutualism
    – symbiotic relationship between two organisms that confers fitness to both
  25. Ontogeny and Phylogeny
    – Similarities in stages of development (ontogeny) can be used to determine evolutionary relationships between organisms.