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4.1: Evolution - History, Evidence, and Mechanisms

  • Page ID
    83808
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    Learning Objectives
    • Explain evolution as an underlying theme in biology
    • Describe adaptations as a general concept
    • Describe the wide range of adaptations of individual species use to interact with and adjust to variations in their environment 
    • Recognize misconceptions about the theory of evolution
    • Identify the major requirements of natural selection
    • Explain the relationships among adaptation, natural selection, and evolution
    • Compare and contrast additional mechanisms of evolution: mutation, genetic drift, gene flow, and genetic recombination.
    • 4.1.1: Understanding Evolution
      Evolution, the unifying theory of biology, describes the change and diversification of species over time. All species of living organisms, including bacteria and chimpanzees, evolved at some point from a different species. Although it may seem that living things today stay the same, this is not the case: evolution is a gradual and ongoing process.
    • 4.1.2: Evidence of Evolution
      Evidence of evolution includes fossils, embryology, vestigial structures, homology, modern case studies, and human-influenced evolution ('artificial' selection).
    • 4.1.3: Natural Selection and Adaptive Evolution
      Natural selection drives adaptive evolution by selecting for and increasing the occurrence of beneficial traits in a population. Natural selection only acts on the population’s heritable traits: selecting for beneficial alleles and, thus, increasing their frequency in the population, while selecting against deleterious alleles and, thereby, decreasing their frequency. This process is known as adaptive evolution.
    • 4.1.4: Additional Mechanisms of Evolution
      In addition to natural selection, the evolution of populations is also influenced by mutation, genetic recombination, genetic drift, and gene flow.

    This page titled 4.1: Evolution - History, Evidence, and Mechanisms is shared under a CC BY-SA 4.0 license and was authored, remixed, and/or curated by Tara Jo Holmberg.