11U Evolution Unit 4

Cards (36)

  • What is evolution?
    Any change in the heritable traits within populations through successive generations
  • Can an INDIVIDUAL evolve?

    No!
  • Heritable traits can be structural, physiological, or behavioral
  • Characteristics/Mutations can be neutral, beneficial, or harmful
  • Evolution results in the diversity of genes which allows species to survive environmental changes
  • What does the theory of catastrophism suggest?

    The Earth has gone through many global catastrophes which have wiped out entire species
  • What does the theory of uniformitarianism suggest?

    Geological changes are slow and gradual. These processes occur today and have not changed throughout Earth's history.
  • What are homologous structures?
    They are similar in anatomy and development pattern, HOWEVER their functions are different
  • What are analogous structures?
    Similar in functions HOWEVER are different in anatomy and development pattern
  • Are homologous or analogous structures passed down from ancestors?
    Homologous structures.
  • Convergent evolution occurs when organism that are exposed to similar environmental pressures develop similarities in their appearance
  • Divergent evolution occurs when a common ancestor developed different adaptations due to different environmental pressures which caused their appearance to become distinct
  • Convergent evolution CAN'T be traced back to a common ancestor
  • What phrase is commonly used to describe Darwin's theory of evolution?
    Survival of the fittest
  • What phrase is commonly used to describe Lamarck's theory of evolution?
    Habitat modifies form
  • What is the "scientific" meaning of "Survival of the fittest"?
    Organisms that are BEST suited for their environment are the fittest and survive long enough to reproduce
  • Main ideas of Natural selection:
    1: There MUST be competition among organisms for survival
    2: There is VARIATION within a population
    3: Organisms adapt accordingly to their environment
    4: Must be able to mate
  • What is speciation?
    New species arise from existing ones through the accumulation of genetic changes over time.
  • What is a species?
    Group of organisms that can interbreed and produce fertile offspring.
  • What is artificial selection?
    Selective breeding of plants and animals by humans to promote desirable traits. (Same as natural selection however instead of nature favoring traits it's humans)
  • What animals did Darwin's closely study on his travels to the Galapagos Islands?
    Finches
  • Vestigial Structures are body parts with no apparent function but may have a function in the past
  • The 5 main key categories that support the theory of evolution by natural selection are:
    1: Biogeography
    2: Fossil records/paleontology
    3: Comparative Biochemistry
    4: Comparative Anatomy
    5: Comparative embryology
  • What is microevolution?
    A change in a populations gene pool over a SHORT period of time
  • What are the 5 mechanisms of microevolution?
    Bottleneck and Founder effect, Gene flow, Non-random mating, mutations, natural selection
  • Three types of natural selection: Directional, Disruptive, and Stabilizing
  • Stabilizing selection favors the intermediates of a population and is against extreme traits
  • Directional selection favors one extreme of a population while being against the other extreme
  • Disruptive selection favors both extremes of a population while being against the intermediate
  • Pre-zygotic isolating mechanisms prevents the mating or fertilization
  • What are the 5 types of pre-zygotic isolating mechanisms?
    ecological, temporal, behavioral, mechanical, and gametic.
  • Temporal isolation occur when two species are separated by timing barriers
    Example: Different blooming seasons or mating seasons
  • Ecological isolation occurs when a species is geographically isolated from other species within the same habitat
    Example: Water snakes, terrestrial garter snakes
  • Behavioral isolation occurs when a certain behavior used for breeding prevents the interbreeding of two species
  • Mechanical isolation occurs when differences in the structure of sex organs prevents fertilization
    Example: Lock and key system for insect genitals
  • Gametic isolation occurs when mating occurs but the formation/fertilization of a zygote fails
    • Chemical incompatibilities (PH)
    • Biochemical barriers (Receptor recognition)