Evolution - Exam Study

Subdecks (4)

Cards (47)

  • Speciation
    The formation of a new species (macro evolution)
  • Species
    Members of a population that have the ability to breed with each other under natural conditions, producing offspring that can reproduce
  • Prezygotic isolating mechanisms

    • Ecological: occupy different habitats
    • Temporal: breed at different times
    • Behavioural: give wrong mating signals
    • Mechanical: parts wont fit
    • Gametic: gametes won't join
  • Postzygotic isolating mechanisms

    • Zygotic mortality: zygote dies
    • Hybrid invariability: it doesn't live long
    • Hybrid infertility: it is infertile
  • Modes of speciation

    • Allopatric Speciation: speciation as a result of geographical isolation
    • Sympatric Speciation: evolution of populations within the same geographical area into separate species
  • Most common mode of speciation is from geographical isolation
  • Darwin's theory of evolution by natural selection explains how species change over time through the accumulation of small genetic changes (mutations) and selective pressures from environmental factors.
  • Divergent Ecolution: 2+ species evolve increasingly different traits
  • Convergent ecolution: 2 or more species bome increasingly similar in phenotype in response to selection pressures
  • Adaptive Radiation: divergent evolution occuring so fast that 1 species gives rise to 3+ species
  • Coevolution: 2 species that are totally dependant on each other for survival, and therefore evolve together
  • homologous features: same origin, different functions now
  • analogous features: similar in funciton but not in origin
  • vestigial features: non-functioning structures homologous to functioning structures in related species.
  • Darwin's postulates
    • Many more are born in each generation than will survive and reproduce
    • There is variation among individuals
    • Individuals with certain characteristics have a better chance of surviving and reproducing than individuals with other characteristics
    • At least some characteristics resulting in differential reproduction are inheritable
    • Enormous spans of time were available for slow change
  • Darwin sailed on the HMS Beagle along the South American coast

    1831
  • Darwin's role
    Captain's mate, became the naturalist
  • Darwin published 'On the Origin of Species by Means of Natural Selection'
  • Lamarck
    Organisms respond to felt needs
  • Characteristics acquired by an individual during its lifetime

    Are transmitted to their offspring
  • Characteristics of each generation

    Would be by all that happened to the members of the preceding generation