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Mechanisms of Evolution Terms

Get down with the lingo


Something that helps a species thrive and survive. This could be a structure, behavior, or process. It's especially helpful when a contestant on Survivor.

Adaptive Mutations

Mutations that positively influence an organism's survival.


Different variants of a gene, like the King of Hearts and the King of Diamonds.

Allopatric Speciation

When two species diverge because of geographic boundaries, like a mountain or a wall.

Bottleneck Effect

When a population goes through a very difficult time and not everyone makes it out Alive.


When u c 2 species evolve 2gether. Possibly due to the fact they are BFFs.

Convergent Evolution

Evolution of two strikingly similar phenotypes in two very different species with no common ancestor. The phenotypes evolved independently.

Directional Selection

Selection for one end of a phenotypic spectrum.

Disruptive Selection

Selection for the two ends of a phenotypic spectrum.


A gradual change in genotype that happens over numerous generations that results in a phenotypic change.


Not the ability to do 50 burpees in one workout session. Related to evolution, it's the ability to survive and reproduce, passing on favorable genotypes to offspring.

Founder Effect

When a population is started by very few individuals, this effect describes the resulting change on allelic frequencies.

Gene Flow

When diversity in the gene pool increases due to the exchange of alleles between populations or species as a result of mating.

Gene Pool

All the genes, alleles of those genes, and neon-colored swim noodles in a total population.

Genetic Drift

Differences in an allele's frequency due to random events that change the members of a population.

Genetic Equilibrium

When allelic frequencies are unchanging.


Not the type of denim you prefer. Nature can't tell the difference between boot cut and skinny jeans. A genotype is the genetic composition of a living thing that influences a particular trait or phenotype.

Hardy-Weinberg Equilibrium

Assuming no evolution, this equation describes the frequency of a specific allele.


Able to be passed down to offspring.


Evolution happening on a large scale in a larger amount of time on many traits.


Evolution happening on a small scale in a small amount of time on a few traits.


When animals pick up and leave to a new zip code. This is often done regularly, like Snowbirds in Miami Beach.


A change in the DNA sequence.

Natural Selection

Proposed by the man, Charles Darwin. Natural selection is a mechanism of evolution that says traits that are favorable to a population's survival are passed down to their offspring.


What you see for a specific trait, which is influenced by both genotype and the environment.

Prezygotic Isolation Barrier

Mechanisms that prevent different species from mating and producing zygotes.


A trait that is influenced by many genes.


More than two sets of chromosomes (more than diploid).


A group of organisms that belong to the same species and occur within the same geographic area.

Postzygotic Isolation Barrier

Mechanisms that prevent the zygotes from different species from surviving, becoming adults, and voting. If they do all these things, then they are likely sterile and unable to produce offspring themselves

Sexual Selection

When there is competition for mates, certain traits will be favored. Owning a candy store is always desirable.


A group of similar organisms. Members of the same species are able to mate and reproduce. It might be said that Romeo and Juliet should have been two separate species, at least if their parents had anything to do with it.


When one species turns into two species.

Stabilizing Selection

Selection for the average of the trait, which reduces variety.

Sympatric Speciation

Speciation not caused by physical isolation.

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