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Genetic Drift

The gradual changes in gene frequencies in a population due to random events

Gene Flow

exchange of genes between populations


changes in the genetic material

Natural Selection

a natural process resulting in the evolution of organisms best adapted to the environment

Non-Random Mating

selection of mates with preferred phenotypes


relationship in which two species live closely together


symbiotic relationship in which both species benefit from the relationship


When one member benefits from another and the other is neither benefitted or harmed.


relationship that benefits one species and harms the other


the ratio of live births in an area to the population of that area


the ratio of deaths in an area to the population of that area

Growth Rate

the rate of increase in size per unit time


Interaction between organism in which one consumes another, leads to species adaptations: jellyfish

Density-Dependent Factor

limiting factor that depends on population size

Density-Independent Factor

limiting factor that affects all populations in similar ways, regardless of population size

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