EVOLUTION

• Common descent


  How species share a common ancestry
• Speciation


  The process by which organisms change and evolve to form new species
• Gradualism


  Small incremental changes that may happen during the process of evolution
• Natural selection


  How organisms with favorable traits are more likely to survive and pass on their traits to their offspring
• Unified theory of evolution


  • Modern evolutionary theory
• Charles Darwin


  On the Origin of Species
• Gregor Mendel


  Heredity
• Modern Integration of Genetics to Darwin's Evolutionary Theory


  1. Mechanism (how the traits of organisms are coded for)

  2. Inheritance (basis of how traits are passed)

  3. Changes (explanation of how traits can change from one generation to another over time)
• Mutations


  Alterations in the DNA sequence; permanent changes that are inheritable
• Discovered the DNA molecule

  Friedrich Miescher
• Adaptation


  Refers to both the mechanism of adjusting to environmental changes and the features that organisms have or use to survive in their habitats
• Adaptations are not universal
• Not all of the traits that organisms have are products of adaptations
• Genetic drift


  The change in the allele frequencies that occur in a population as a result of chance
• Population bottleneck


  A drastic reduction in a population due to the occurrence of natural events
• Fields primarily concerned with studying the evolutionary relationships among organisms


  • Phylogeny
  • Systematics
• Phylogeny and Systematics


  Deciphering how species are related to each other and how lineages have diverged in order to form new species
• Phylogenetic change


  Changes that occur during a species' evolutionary history across generations
• Ontogenetic change


  Changes that occur in the lifespan of one organism
• Comparative anatomy


  The field that studies the comparisons between the structures of organisms to establish their evolutionary relationships
• Biogeography


  A branch of biology that deals with the distribution of species across the world
• Historical biogeography


  Concerns itself with the past and present distribution of organisms
• Scientific theory


  One that is grounded on facts and laws and incorporates rigorous scientific testing or experimentations
• Evolution is a fact
• Evolution does not have a goal
• Survival of the fit


  Organisms that meet the requirements of their environment have higher chances of survival and passing on their genes to their offspring
• Chimpanzees share common ancestors with humans, and our lineages diverged and produced the extant species that are present on Earth today
• Concepts included in the unified theory of evolution


  • Darwin's concepts
  • Many others
• Phylogenetic changes refer to those that happen across generations, whereas ontogenetic changes refer to those that happen within an organism's lifespan
• Biogeography deals with the distribution of organisms, and historical biogeography adds the factor of time in the study of the distribution of organisms
• Adaptation


  Refers to both the mechanism of adjusting to different forms of environmental changes and the features that organisms utilize to improve their chances of survival in particular habitats