Natural Selection Flashcards
What is micro evolution?
Evolution within species, genetic variation across generations, small scale changes within human time frames
What is macro evolution?
Large scale changes that usually give rise to new species, long time frames (geological time scales)
What are the conditions for natural selection
Reproduction
Inheritance
Variation
Differential Success
Stabilizing Selection
Phenotypes nearest the mean have highest fitness.
Directional Selection
Phenotypes at one extreme have the highest fitness. Mean trends toward that extreme.
Disruptive Selection
Phenotypes at both extremes have higher fitness than the mean.
Frequency dependent selection
Rarer phenotype has highest fitness until it becomes common. The frequency of a given phenotype oscillates
Altruism
Behavior that reduces individual fitness and increases fitness of others
Kin selection
Favors behaviors that increase reproductive success if relatives
Inclusive fitness
Sun of an individuals own fitness and it’s contribution to success and survival of relatives
Hamilton rule
Defines how benefits to close relatives can outweigh the costs to the altruist
Reciprocal altruism
When altruist has reasonable expectation that the sacrifice will be reciprocated in the future
Sexual selection
If displays of altruism increase mating options
Constraints of Natural Selection
Laws of physics
Evolutionary history
Trade offs
Lack of variation
(environmental change maybe)
Can natural selection result in a perfectly adopted organism?
No because environments and the species within them are always changing
