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2012-01-19 18:25:24
Bio 113

Unit one, chapter 23 An intro to evolution
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  1. Define "Evolution"
    Heritable change in one or more characteristics of a population from one gereration to the next.
  2. Microevolution vs. Macroevolution
    Microevolution: evolution viewed on a small scale as it relates to changes in a single gene or allele frequencies in a population over time.

    Macroevolution: evolution viewed on a larger scale as it relates to the formation of a new species or groups of related species
  3. Define "Convergent Evolution"
    Evolution in which two different species from different lineages have independently evolved similar characteristics because they occupy similar environments.
  4. Define "Homology"
    Refers to a similarity that occurs due to descent from a common ancestor.

    May involve anatomical, developmental, or molecular features.
  5. Define "Anatomical Homologies"
    Evolutionary related species may possess homologous structures that have been modified in ways that allowed them to be used differently by each species. In some cases, such structures are no longer needed and degenerate to vestigial structures.
  6. Define " Developmental Homologies"
    An analysis of embryonic development often reveals similar anatomical features that point to past evolutionary relationships.
  7. Define " Molecular Homologies"
    At the molecular level, certain characteristics are found in all living cells, suggesting that all living cells are derived from a common ancestor. In addition, species that are closely related evolutionarily have DNA sequences that are more similar to each other than they are to those in distantly related organisms.