Evolution

Adapt

A trait that you are born that becomes common among a species due to its fitness in an environment.

Acquired characteristics

Lamarck’s misconception of traits being acquired through experience.

natural selection

Organisms with favorable traits will survive reproduce more.

criteria of natural selection

over reproduction

genetic variation

competition for survival

uneven reproduction

uniformitarianism

Geological processes don’t change with time, but with natural forces.

gradualism

geological processes results are from small changes over a long period of time.

catastrophism

sudden geological catastrophes cause the start of mass extinctions.

competition

a population will fight for resources if limited.

biogeography

how organisms were distributed across the earth as evidence for evolution

island trend

island species closer to the mainland species are more similar

comparative morphology

comparing anatomical structures to support evidence of evolution

morph

structure

homologous structure

organisms with a common ancestor share a similar skeletal structure but for different functions

divergent evolution

organisms with the same common ancestor will evolve differently in response to their environment.

vestigial structures

less useful body parts that underdeveloped throughout evolution due to the lack of need for them. They can be used to discover a common ancestor.

convergent evolution

unrelated species develop similar characteristics in response to their similar environment.

analogous structures

anatomic structures that have the same function, but aren’t similar.

fossil

imprints of organisms (poop, bones, tracks, body parts, etc.) for proof of past life. They are only found in sediment.

trace fossil

A fossil of an organism’s activity (footprints, poop)

transitional fossils

a fossil of an intermediate organism between 2 species in the process of evolution

relative dating

Dating a fossil or rock if they’re younger or older than each other by observing what stratum it is in.

law of superposition

new strata layers upon the older one.

absolute radiometric dating

dating a fossil’s age by years through the decay of radioactive isotopes.

similar embryology

the similar appearance of early embryos of different species as evidence for a common ancestor

microevolution

a change in genetic frequency within a population in a short period of time

frequency equation

the number of individuals with the trait / the whole population

p

the frequency of the dominant allele

q

the frequency of the recessive allele

p+q=1

the formula of allele frequency in a total population

evolution

change in a population’s allele frequencies over time.

genetic equilibrium

the frequency for all alleles are the same (50/50)

Hardy-Weinberg Equilibrium

No mutations

no gene flow

infinitely large population

no natural selection

random mating

r

the frequency for a new allele caused by mutation

genetic drift

smaller populations have a greater chance for evolution.

founder effect

a small group of organisms start a new population in a different location

bottleneck effect

an event that drastically shrinks the population.

sexual selection

mates choose who to reproduce with.

intersexual selection

one sex chooses who in the opposite sex to mate with.

sexual dimorphism

different morphology between opposite sexes in the same species.

intrasexual selection

members of the same sex compete to mate with the opposite sex.

gene flow

the movement of alleles into or out of a population

Directional selection

Natural selection that shifts the allele distribution graph to one way.

Disruptive selection

Both extreme traits are favored during natural selection.

Stabilizing selection

When the intermediate trait is favored.

Sexual selection

individuals choose who to mate with based on phenotype (looks)

There are two types: intersexual and intrasexual selection

intersexual selection

one individual attracts another through the display of traits or behaviors.

intrasexual selection

Two individuals of the same sex compete to mate with the opposite sex.

sexual dimorphism

Males and females of a species may have different morphs because of intersexual selection.

4 criteria of natural selection

over reproduction

competition (struggle to survive)

genetic variation

different reproduction (not everyone reproduces the same)