Mechanisms Flashcards
A key factor for an organism to thrive and reproduce depends on how well suited the organism is to the environment
Natural selection
The ability of an individual to survive and reproduce in a specific environment
Fitness
Happens when a change in environment causes a change in the observable spectrum of phenotypes
Directional selection
Occurs when intermediate phenotypes are more likely to survive in the environment
Stabilizing selection
Occurs when extreme phenotypes are more likely to adapt to the environment
Disruptive or Diversifying selection
Nature provides the variation among different organisms so that humans can select the variations that are useful to them
Artificial selection
This type of mechanism is done by farmers and breeders
Selective breeding
Contribute to the population change from one generation to the next
Non-random mating
Individuals are more likely to mate with their close relatives than with distant relatives
Inbreeding
Assortative mating happens when individuals select distant relatives that close relatives as their parents
Outbreeding
Caused by unpredictable changes in allele frequencies due to small population sizes
Genetic drift
Occurs when a sudden sharp decline in the population results in a drastic reduction of the total genetic diversity of the original population
Population bottleneck
Happens when there is a lost of genetic variation because of the migration of a small subgroup in a population
Founder effect
The chance in the structure of a gene caused by alterations in the dna sequence of an organism
Mutation
Occurs when the genetic codon has one altered nitrogenous base
Substitution
