Biology 2020

• 2-Fold+

  asexual females produce twice as much offspring as sexual females
• Acclimation 


  The process of becoming accustomed to new conditions
• Adaptation 


  Heritable trait that increases fitness
• Advantageous mutation

  Beneficial
• Allopatric

  Speciation by geographic separation
• Artificial selection


  Humans select traits
• Balancing selection

  Maintains an allele at some intermediate frequency
• Darwinian Threshokd 


  Moment where genetic transfer moves from horizontal to vertical
• Darwin’s 4 Postulates

  1. Individuals vary in traits
  2. Some variations are heritable
  3. More offspring are produced than can survive
  4. Individuals with more heritable traits are more likely to survive
• Deleterious Mutation


  Harmful
• Directional Selection


  A single allele is favored
• Disruptive Selection

  Favors extremes and against intermediate forms
• Fitness 


  Ability of an individual to produce surviving offspring
• Fitness Tradeoff 


  Compromise between traits
• Genotype


  combination of alleles
• Hadean Eon


  Before life
• Hardy-Weinberg Equilibrium


  Situation in which evolution doesn’t occur
• LUCA

  Last Universal Common Ancestor
• Miller-Urey


  Life began with a spark in a reducing atmosphere
• Neutral Mutation


  No effect
• Parsimony


  Used to identify the most likely phylogenetic tree
• Phenotype


  Observable feature
• Population thinking

  variation
• Postzygotic isolation 


  After birth, born sterile or die
• Prezygotic isolation


  Individuals are prevented from mating
• RNA World

  RNA carried out most of the biochemical functions in early evolution
• Selective Pressure


  Set of environmental conditions
• Speciation 


  Formation of new species
• Stabilizing selection


  Maintains the status quo against the extremes
• Sympatry 


  Species that live in the same geographic area
• Typological thinking

  Everything is perfect
• Vestigial structures 


  Functionless characters that are homologous to functional characters
• Monophyletic


  A common ancestor and all descendants
• Paraphyletic


  Common ancestor and some descendants
• Polyphyletic


  Does not include common ancestor
• Great Oxidation Event 


  Sudden increase of earths level of oxygen
• Banded Iron Formation (BIF)


  Sedimentary rocks that indicate repeated episodes of iron oxidation
• Gene Flow


  Occurs when individuals leave one population join another and breed
• Horizontal Gene Transfer 


  Transfer of genetic material between organisms that are not parent and offspring
• Somatic Cells 


  Non-reproductive cells