evolution speciation

  1. Evolution
    change in a population's inherited characteristics or traits from generation to generation

    allele frequencies change
  2. Speciation
    evolutionary process by which two or more separate species arise
  3. phyletic evolution
    entire species changes to a degree that it can no longer be considered the same species.
  4. no change in allele frequencies over time, unless...
    Hardy Equilibrium a disturbing influence has occured like:

    • mutations occur
    • genetic drift
    • migration / gene flow
    • non-random mating
    • natural selection
  5. Polyploidy
    individual has 2x (at least) the number of chromosomes from one parent
  6. chromosome fusion
    • genetic code of humans and chimpanzees are 99% similar
    • cannot interbred
  7. Natural Selection
    • each individuals’ traits vary
    • some traits are inheritable
    • not all offspring will survive (limited resources)
    • individuals with the most advantages traits will survive
  8. Speciation
    the formation of two or more contemporaneous species from a common ancestor
  9. Allopatric speciation
    new species form after populations are geographically isolated
  10. sympatric speciation
    new species form within a geographically continuous area
  11. Adaptive radiation
    • the development of many species from 1 ancestral population
    • new species evolve to occupy different niches
  12. Divergent evolution
    • individuals from 1 ancestral population diverge into new species
    • different physiological traits & morphologies
  13. Convergent Evolution
    • un-related species develop similar physiological traits & morphologies
    • geographically isolated species
    • environments are similar
Card Set
evolution speciation
Natural resources midterm