Evolution and Diversity Test #1 Vocab

Natural selection, basic evolution terms, images of protists

Evolution

The allele frequency shifts in a population over time

Natural Selection

Organisms become adapted to their circumstances which causes a change in allele frequency in a population

Population

Localized group of individuals capable of interbreeding and producing fertile offspring

Gene Pool

All the alleles for all loci in a population

Fixed

All the individuals in a population are homozygous for the same allele

Mutation

Provides new alleles/genes

Gene Flow

Movement of alleles in/out of a population

Genetic Drift

Evolution occurring due to chance events

Population Bottleneck

Size of a population drastically reduced so that only a few individuals are able to contribute genes to the next generation

Founder Effect

Isolated colonies founded by a small number of organisms

Directional Selection

Shifts traits in a specific direction

Stabilizing Selection

Favors individuals with average traits, acts against individuals that deviate too far from the mean

Disruptive Selection

Favors individuals at both extremes of a trait, and selects those without average traits

Balanced Polymorphism

Two or more phenotypes are maintained in a population because each is favored by a difference environmental force

Speciation

Origin of new species

Microevolution

Consists of changes in allele frequency in a population over time

Macroevolution

Refers to broad patterns of evolutionary change above the species level

Sister Taxa

Groups that share an immediate common ancestor

Rooted Tree

Includes a branch to represent the last common ancestor of all taxa in the tree

Basal Taxon

Diverges early, near the common ancestor of the group

Polytomy

Branch from which 2 or more groups emerge

Homology

Similarity due to shared ancestory

Analogy

Similarity due to convergent evolution

Convergent Evolution

Similar environmental pressures and natural selection produce similar adaptations

Clade

A group that includes an ancestral species and all its descendants

Monophyletic Clade

Includes a group of organisms with a single common ancestor and all its descendants

Paraphyletic Clade

A group of organisms with a common ancestor and some of its descendants

Trypanosoma

Plasmodium

Paramecium

Radiolarians

Foraminiferans

Red Algae

Spirogyra

Volvox

Diatoms

Chara

Dinogflagellates

Euglena