L.10 Evolution Flashcards
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?
- Stabalizing selection: Keeps phenotypes within a narrow range, excluding extrems
- Directional Selection: Moves the average phenotype towards one extreme.
- Disruptive Selection: moves them to both extremes and can lead to speciation.
- 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