Evolution

Evolution

1. Micorevolution

   • Shorter period of time
   • Artificial Selection
     • Breeding where individuals with desired traits are picked as parent generation
     • Creates new breeds/variation
   • Changes in gene frequency
     • Positive, negative or no effect
     • Genetic mutation
       • Insertion
       • Deletion
       • Inversion
     • Within population/species
     • Natural

2. Macroevolution

   • Happens over millenia
   • Speciation
     • Reproductive isolation
       • Pre-zygotic
         • Prevention of fertilization
           • Mechanical
           • Gametic
         • Prevention of mating
           • Temporal
             • Different reproductive cycles
           • Habitat isolation
           • Behavioural isolation
             • Mating signals
       • Post-zygotic
         • Prevention of maturation and reproduction
           • Mortailty
           • Infertile
     • Sympatric
       • Significant mutation happens to work
     • Allopatric
       • Prevents interbreeding, species slowly change
       • Caused by barrier

3. Charles Darwin

   • Surveyed South America; Galapagos islands 1831-1836
   • Natural Selection
     • Observations
       • In each generation, more off-spring are produced than can survive
       • Populations do not grow in size
         • Individuals within a population compete for resources
           • Over time the population changes as advantageous heritable characterisitcs become more common generation after generation
       • Food and other resources are limited
       • Individuals within all populations vary
       • Many variations are heritable
         • Some individuals will inherit traits that give them a better chance of surviving and reproducing