allopatric speciation

speciation that occurs via geographic separation

allopatry

occurring in different geographic areas

allele frequency

rate at which a specific allele appears within a population

aposematic coloration

warning coloration used as a defense against predators

Arthropoda

protostome phylum including insects, spiders, and crustaceans

Batesian mimicry

harmless species mimics a harmful species

Bilateria

animals with bilateral symmetry

biotic potential (rmax)

maximum possible growth rate of a population

Bryophyta

nonvascular land plants such as mosses

carrying capacity (K)

maximum number of individuals an environment can support

Chordata

animals possessing a notochord during some stage of development

Cnidaria

phylum including jellyfish, corals, and sea anemones

communication signals

methods animals use to communicate through sound, sight, smell, or touch

competitive exclusion principle

no two species can occupy the same niche in the same place and time indefinitely

Ctenophora

comb jellies that move using rows of cilia

deceitful communication

communication in which the signaler manipulates or exploits the receiver

Deuterostomes

bilaterians in which the anus develops before the mouth

directional selection

natural selection favoring one extreme phenotype

dispersal

movement of individuals to new geographic areas

diversifying selection

natural selection favoring multiple extreme phenotypes

Echinodermata

marine deuterostomes including sea stars and sea urchins

evolution

change in allele frequencies in a population across generations

exponential growth

rapid accelerating population growth under unlimited resources

fixed action pattern

instinctive behavior sequence that continues once initiated

food web

interconnected feeding relationships within a community

fundamental niche

full range of environmental conditions a species could theoretically occupy

fusion

merging of diverging populations after reproductive barriers weaken

gametic isolation

reproductive isolation caused by incompatibility between sperm and egg

genetic drift

random change in allele frequencies due to chance

Gymnosperms

seed plants that do not produce flowers or fruits

habitat isolation

reproductive isolation caused by populations occupying different habitats

hybrid inviability

hybrids fail to survive to reproductive age

hybrid sterility

hybrids survive but are unable to reproduce

hybrid zone

region where closely related species meet and interbreed

interspecific competition

competition between different species

iteroparity

life history strategy involving multiple reproductive events

J-shaped growth curve

graph shape associated with exponential growth

keystone species

species with disproportionately large effects on ecosystem structure

learned behavior

behavior modified through experience

life history strategy

pattern of growth, reproduction, and survival shaped by evolution

logistic growth

population growth slowing as carrying capacity is approached

Mollusca

protostome phylum including snails, clams, and squids

Müllerian mimicry

harmful species sharing similar warning coloration

mutation

change in DNA sequence

natural selection

differential survival and reproduction of individuals due to inherited traits

Nematoda

protostome phylum of roundworms

niche

ecological role and environmental requirements of a species

phylogenetic tree

diagram showing evolutionary relationships

Polypodiopsida

ferns and related vascular plants

population growth model

mathematical description of population growth patterns

postzygotic barrier

reproductive isolation occurring after fertilization

predation

interaction where one organism kills and consumes another

prezygotic barrier

reproductive isolation occurring before fertilization

Protostomes

bilaterians in which the mouth develops first

realized niche

actual niche occupied after competition and environmental limitations

reinforcement

strengthening of reproductive barriers due to low hybrid fitness

reproductive isolation

prevention of gene flow between populations

resource partitioning

division of resources among competing species

signals

forms of communication detected through senses such as hearing, sight, smell, or touch

species interactions

ecological relationships between species such as competition, predation, and mutualism

stabilizing selection

natural selection favoring intermediate phenotypes

survivorship curve

graph showing survival patterns across age groups

territoriality

defense of an area for exclusive resource use

types of mimicry

evolutionary resemblance between species for protection or predation advantages

Angiosperms

flowering plants producing seeds enclosed within fruits

Annelida

segmented worm phylum including earthworms and leeches

aggressive mimicry

predator resembles something attractive or harmless to prey

background extinction

normal rate of species extinction over time

biodiversity

variety of life at genetic, species, and ecosystem levels

biodiversity hotspot

area with many endemic species and extensive habitat loss

biomagnification

increasing concentration of substances at higher trophic levels

buffer zone

protected surrounding habitat around a preserve

bush meat

wild animals hunted for food

Carson, Rachel

author of Silent Spring who warned about dangers of pesticides

chemical diversity

variety of chemical compounds produced by organisms

chytridiomycosis

fungal disease causing major amphibian declines

ecosystem diversity

variety of ecosystems in a region or on Earth

ecosystem services

benefits humans receive from ecosystems

Endangered Species Act

U.S. law protecting threatened and endangered species

endemic

species native to and restricted to a specific geographic area

exotic species

species introduced outside their native range

genetic diversity

variety of genes within a species

greenhouse effect

warming caused by gases trapping heat in Earth’s atmosphere

greenhouse gases

gases such as carbon dioxide and methane that trap heat

invasive species

nonnative species that spreads aggressively and harms native species

latitudinal diversity gradient

pattern where biodiversity is greater near the equator

mass extinction

rapid widespread loss of species over a short geological period

megafauna

very large animals

Myers, Norman

scientist who pioneered biodiversity hotspot research

nature preserve

protected area set aside for conservation

phylogenetic diversity

biodiversity measure incorporating evolutionary relationships

Pleistocene extinction

extinction event involving loss of many megafauna species

regulating services

ecosystem services involving regulation of natural processes

resilience

ability of a community to recover from disturbance

secondary plant compounds

defensive chemicals produced by plants

species-area relationship

relationship between area size and number of species

species diversity

measure including both species richness and evenness

species evenness

relative abundance of species in a community

species richness

total number of species in a community

supporting services

ecosystem functions necessary for other services

tragedy of the commons

overuse of shared resources because individuals act in self-interest

white-nose syndrome

fungal disease devastating North American bats

wildlife corridors

habitat connections allowing movement between preserves