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Flashcards in L.10 Evolution Deck (8)
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Definition of natural selection

Variations exist between individuals and advantageous variations - those that increase an individuals fitness for survival or adaptation to the environment- afford the most opportunities for reproductive success.


What is the model synthesis model (neo-Darwinism)

accounts for mutation and recombination as mechanisms of variation and considers differential reproduction to be the mechanisms for reproductive success

Differential reproduction is the idea that those organisms best adapted to a given environment will be most likely to survive to reproductive age and have offspring of their own.


What is inclusive fitness? 

Considers an organisms success to be based on the number of offspring,

supporting offspring

ability of offspring to then support others

survival of offsping or relatives ensures appearance of genes in subsequent generations


What is punctuated evolution?

Considers evolution to be very slow with intermittent rapid burst of evolutionary activity


Different types of selections lead to changes in phenotype, referring back to the graph models, what are the 4 types of selections?

  1. Stabalizing selection: Keeps phenotypes within a narrow range, excluding extrems
  2. Directional Selection: Moves the average phenotype towards one extreme.
  3. Disruptive Selection: moves them to both extremes and can lead to speciation.
  4. Adaptive Radiation: is the rapid emergence of multiple species from a common ancestor, each of whcih inhabit a different niche.


Two species can evolve with different relationship patterns, what are those 3 patterns?

Divergent Evolution: Two different species sharing common ancestor diverge.

Parallel Evolution: Twp different species sharing common ancestor evolve similary due to analogous selection pressures

Convergent Evolution: Species not sharing common ancestor evolve similary b/c of similar selection pressures



According to the molecular clock model...

The degree of differences in the genome between two species is related to the amount of time since the two species broke off from a common ancestor.


Biological definition os Species

The largest group of organisms capable of mating and creating fertile offspring.

Species are reproductively isolated by pre or post-zygotic mechanisms