Evolution

Population

A group of the same species

Gene pool

The geotypes present in a population

mutations

random changed in DNA

fitness

An organism ability to survive

Natural selection

favors traits that are more fit. causes evolution as more fit genotypes will appear in the gene pool.

migration

individuals in a population leave or enter a population randomly. immigration- enter (in) emmigration- leave (exit)

Nonrandom Mating

Mating is not done randomly

genetic drift

a shift in allele frequencies in a population due to a random chance. can be bad for small populations

bottleneck

A catastrophic event that randomly leaves a few survivors to repopulate. can lead to extinction

directional selection

change that favors individual with one extreme phenotype

stabilizing selection

change that favors the average/ intermediate

disruptive selection

change that favors either extreme

artificial selection

when mates are chosen (breeding)

sexual selection

individuals pick makes

sexual dimorphism

the differing appears of males and females in a species

embryology

the study of fetus in development (shows evolution)

homologous structures

similar structure but different functions

analogous structures

different structure same function

vestigial structures

were once important for survival but are no longer used in the same way

adaptation

a change over generations that coincides with an environmental change

acclimation

a short term help to a problem to

fossil record

can look at fossils of a species long ago to see how they evolved over time and change

comparative anatomy

can compare to other bone structures to show a connection in structures

mutagen

mutation coming from external influence. EX. too much sun burns leads to skin cancer

Germline Mutation

mutations that get passed on. can cause evolution.

EX- sickle cell disease

Somatic mutations

Mutations that do not get passed on. Cannot cause evolution.

EX- skin and lung cancer. stuff caused by mutagens