Evolution total

evolution

heritable change in a population from one generation to the next

heritable

able to be passed down from offspring

mutation

heritable change in genetic material

lineage

series of species form a line of descent

vertical evolution

mutations in lineage alter characteristics from one gen to the next

horizontal gene transfer

transfer of genetic material from one organism to another thats not its offspring

microevolution

change in genes/alleles in a species over time

macroevolution

formation of new species over time

natural selection

changes in a populations to better suit them to reproduce in environment

biogeography

geographic distribution of species around the world

convergent evolution

unrelated species develop similar features because they live in similar environments

fossil record

historical sequence of preserved remains

Anatomical Homologies

Structured inherited from common ancestor that share a basic layout

developmental homologies

similarities visible during early embryo stages that disappear in adults

molecular homologies

shared DNA sequences across species

vestigial structure

homologous features that lost use

molecular evolution

process of evolution at chromosome, gene, and protein levels

Orthologs

genes in different species that evolved from a common ancestor through a speciation event (keep functions)

paralog

genes within the same species that arose from a gene duplication event (new functions)

horizontal gene transfer

gene transfer from one to another organism that is not its offspring (subject to natural selection)

polymorphism

presence of 2 or more variations of a character in a population

monomorphic

single allele in a population

genetic drift

change in allele frequencies over time due to random chance

bottleneck effect

environmental event dramatically reduces population size (natural disaster, disease etc)

Founder effect

small group of individuals breaks off from a larger population to establish a new colony, carrying only a fraction of the original group's genetic diversity

Neutral variation

genetic differences that do not affect reproductive success (most)

Gene Flow

individuals migrate between populations with different allele frequencies which increases genetic diversity

Inbreeding

form of nonrandom mating where related individuals have offspring

inbreeding depression

homozygotes (from inbreeding) have lower fitness

assortative mating

Individuals choose partners with traits similar to their own

dissassortative mating

Individuals actively choose partners with traits different from their own

Directional Selection

Nature favors 1 extreme trait which shifts the population to that trait over time

Stabilizing selection

Nature favors middle trait/average and gets rid of both extremes

Diversifying selection

nature favors extreme, middle/average loses out (varied environments)

Balancing selection

nature keeps multiple traits balanced so no single trait takes over

4 requirments for evolution via natural selection

Overproduction, variation, heritability, differential reproductive success