Unit IV: Evolution vocab

• linnaeus carl was a botanist and founder of taxonomy
• taxonomy is binomial nomenclature 


  genus and species ( humans = homo sapien )
• cuvier georges was a vertebrate zoologist that developed comparative anatomy
• the theory of catastrophism was an attempt to explain why the fossil record appeared as if species were changing over time


  • after each in a series of catastrophes the mass extinctions & repopulations made it appear as if species were changing
  • established extinction as a fact
• lamarck baptiste - jean was an invertebrate zoologist that proposed the first evolution theory
• the theory of acquired characteristics states

  • more complex species are descendants from less complex ones
  • every species has a built in drive to become more perfect
  • features that are used extensively become larger and those not used become smaller and this information is inheritable
• lyell charles & hutton james were geologists that published the " principles of geology "
• the theory of uniformitarianism

  • earth has been subject to continuous cycles of erosion and uplift
  • earth is dynamic and not static
  • changes have occurred over vast amounts of time through processes that have always been on earth
  • earth is much older than previously thought
• malthus robert thomas was a mathematician & population scientist who invented the growth curve
• the carrying capacity is the maximum number of individuals that an environment can support
• darwin charles invented the theory of natural selection
• the theory of natural selection

  1. in most species the number of individuals in a generation that survive and reproduce is small
  2. variations among individuals exist ( everyone is unique and the differences are inheritable )
  3. limited resources & large numbers of individuals lead to a struggle for existence ( viable traits : traits that allow you to access resources )
  4. inherited favorable characteristics to that environment become more common from one generation to the next ( fit traits : a trait that allows you to have more offspring )

  • the smallest unit that can evolve is the population
• diploidy is when some traits are protected from elimination in the gene pool because they are recessive
• random fertilization adds new traits to a family line
• mutations are the only way to add new traits to a species
• independent assortment refers to the randomness of which chromosome is given off from each parent
• population genetics 


  fuses darwinian evolution & mendelian genetics

  variation exists in populations

  variation is caused by genes

  genes are inheritable
• population is all members of a species living in an area
• biological species are members who have the potential to breed & produce viable offspring
• viable means healthy & fertile
• morphological species define species by their features
• ecological species defines species by their niche
• niche describes an organisms place in the ecosystem
• gene pool is all the alleles of all the genes in a population
• microevolution is change in the percentage of genes in a population over generations


  generally allele percentage will not change over generations unless were looking at causes of microevolution
• generating diversity

  1. diploidy
  2. random fertilization
  3. mutations
  4. independent assortment
  5. natural selection
• causes of microevolution

  1. natural selection
  2. mutations
  3. gene flow
  4. genetic drift
  5. nonrandom mating
• gene flow is the movement of alleles in or out of a population
• genetic drift is a change in the gene pool as a result of chance
• the bottleneck effect is reduction in a population size unselectively
• founder effect is when a small group branches off the larger population

  • some alleles are over or under represented
  • as the population regrows frequencies will not match that of the original
• nonrandom mating is when an individual chooses a mate based on phenotypic similarity 


  eliminates the heterozygous condition

  nonrandom mating makes it easier for natural selection to eliminate traits from the gene pool
• speciation is the formation of new species from a common ancestor


  macroevolution
• reproductive isolators ( prezygotic )

  • behavioral isolation
  • mechanical isolation
  • genetic isolation
  • habitat isolation
  • temporal isolation
• behavioral isolation is a visual autotomy and chemical signals used in mating do not match
• mechanical isolation is when the size & shape of reproductive organs do not match
• genetic isolation is when the gametes are incompatible and fertilization does not occur
• habitat isolation is when species occupy different habitats who do not come in contact
• temporal isolation is when different species mate at different times or seasons
• reproductive isolators ( post zygotic )

  • hybrid inviability
  • hybrid sterility
  • hybrid breakdown