Gene pool
The combined alleles of all of the individuals in a population.
Allele frequency
A measure of how common a certain allele is in a population.
Mutation
A random change in the DNA of a gene.
Recombination
New allele combinations form in offspring through this process.
Hybridization
The crossing of two different species that share common genes.
Normal distribution
This type of distribution is when the frequency is highest near the mean value and decreases toward each extreme end of the range.
Microevolution
The observable change in the allele frequency of a population over time.
Directional selection
A type of selection that favors phenotypes at ONE extreme end of a traits range.
Stabilizing selection
A type of selection where the INTERMEDIATE phenotype is favored and becomes more common in a population.
Disruptive selection
Occurs when BOTH extreme phenotypes are favored by selection.
Gene flow
The movement of alleles from one population to another.
Genetic drift
Changes in allele frequencies due to chance.
Bottleneck effect
The effect of a destructive event that only leaves a few survivors in a population.
Founders effect
Genetic drift that occurs after a small number of individuals colonize in a new area.
Genetic drift (effects)
-population loses genetic variation,with little variation a population will be less likely to have individuals that can adapt to the environment.
- alleles that are lethal in homozygous individuals maybe carried by heterozygous individuals and become more
Sexual selection
When certain traits increase mating success.
Two types of sexual selection
Intrasexual, Intersexual
Intrasexual selection
Competition among males, such as the butting of big horned sheep. The one who wins the competition wins the female.
Intersexual selection
When males display certain traits that attract the female, such as peacocks fanning out their tails.
Reproductive isolation
When members of different populations can no longer mate successfully with one another.
Speciation
The rise of two or more species from one existing species.
Populations become isolated in many ways
Behavioral barriers, Geographic barriers, Temporal barriers
Behavioral isolation
Isolation caused by differences I courtship or mating behaviors.
Geographic isolation
Involves physical barriers that divide a population into two or more groups. (Ex, lakes, mountains, rivers, dried lake beds, ect.)
Temporal isolation
When timing prevents reproduction between populations. (Really rare)
Natural selection
ISN'T RANDOM!!
Convergent evolution
Evolution towards similar characteristics in unrelated species.
Divergent evolution
When closely related species evolve in different directions, and they become increasingly different.
Coevolution
The process in which two or more species evolve in response to changes in each other.
Coevolution
(Beneficial)
When two species "help" each other survive.
Coevolution
(not benefiting)
To which a species responds to pressure from the other through better adaptions over many generations.
Extinction
The elimination of a species from earth. (2 forms)
Background extinction
Extinctions that occur continuously but at a very low rate, and only effect one or a few species in a relatively small area.
Mass extinction
Much more rare than background extinctions. They often happen at a global level, and are a product of catastrophic events.
Punctuated equilibrium
Episodes of speciation occur suddenly in geological time and are followed by long periods of little evolutionary change.
Adaptive radiation
The rapid evolution of many diverse species from ancestral species.
Gene pool
The combined alleles of all of the individuals in a population.
Allele frequency
A measure of how common a certain allele is in a population.
Mutation
A random change in the DNA of a gene.
Recombination
New allele combinations form in offspring through this process.
Hybridization
The crossing of two different species that share common genes.
Normal distribution
This type of distribution is when the frequency is highest near the mean value and decreases toward each extreme end of the range.
Microevolution
The observable change in the allele frequency of a population over time.
Directional selection
A type of selection that favors phenotypes at ONE extreme end of a traits range.
Stabilizing selection
A type of selection where the INTERMEDIATE phenotype is favored and becomes more common in a population.
Disruptive selection
Occurs when BOTH extreme phenotypes are favored by selection.
Gene flow
The movement of alleles from one population to another.
Genetic drift
Changes in allele frequencies due to chance.
Bottleneck effect
The effect of a destructive event that only leaves a few survivors in a population.
Founders effect
Genetic drift that occurs after a small number of individuals colonize in a new area.
Genetic drift (effects)
-population loses genetic variation,with little variation a population will be less likely to have individuals that can adapt to the environment.
- alleles that are lethal in homozygous individuals maybe carried by heterozygous individuals and become more
Sexual selection
When certain traits increase mating success.
Two types of sexual selection
Intrasexual, Intersexual
Intrasexual selection
Competition among males, such as the butting of big horned sheep. The one who wins the competition wins the female.
Intersexual selection
When males display certain traits that attract the female, such as peacocks fanning out their tails.
Reproductive isolation
When members of different populations can no longer mate successfully with one another.
Speciation
The rise of two or more species from one existing species.
Populations become isolated in many ways
Behavioral barriers, Geographic barriers, Temporal barriers
Behavioral isolation
Isolation caused by differences I courtship or mating behaviors.
Geographic isolation
Involves physical barriers that divide a population into two or more groups. (Ex, lakes, mountains, rivers, dried lake beds, ect.)
Temporal isolation
When timing prevents reproduction between populations. (Really rare)
Natural selection
ISN'T RANDOM!!
Convergent evolution
Evolution towards similar characteristics in unrelated species.
Divergent evolution
When closely related species evolve in different directions, and they become increasingly different.
Coevolution
The process in which two or more species evolve in response to changes in each other.
Coevolution
(Beneficial)
When two species "help" each other survive.
Coevolution
(not benefiting)
To which a species responds to pressure from the other through better adaptions over many generations.
Extinction
The elimination of a species from earth. (2 forms)
Background extinction
Extinctions that occur continuously but at a very low rate, and only effect one or a few species in a relatively small area.
Mass extinction
Much more rare than background extinctions. They often happen at a global level, and are a product of catastrophic events.
Punctuated equilibrium
Episodes of speciation occur suddenly in geological time and are followed by long periods of little evolutionary change.
Adaptive radiation
The rapid evolution of many diverse species from ancestral species.