2.0 biodiversity VOCAB

genetic diversity

genetic diversity

- differences in DNA composition in a given population

- low = inbreeding depression [fewer diversity in genes —> disease/weak health]

- species richness

- species evenness

- abundance

—> number of total species in an area

—> relative proportion of how many individuals are in a species

—> number of individuals of a species in an area

ecosystem diversity

variety of ecosystems in a particular area

—> rise of elevation can increase vegetation diversity for more animal species

evolution

genetically based change in populations of organisms across generations

natural selection

differential survival and reproduction of individuals due to differences in traits

adaptations

traits that change over time to support an increased success in an environment

artificial selection

humans select which individuals to breed [dog breeds]

mutation

an accidental change in DNA that can range from deletion, substitution, or insertion

convergent evolution

very unrelated species acquire similar traits as they adapt

speciation

new species are generated; species become so different that they do not reproduce

allopatric speciation

species form after populations become physically separated over some geographic distance

phylogenetic trees

treelike diagram that represents the history of divergence of species

keystone species

species with strong/wide-reaching impact out of proportion to its abundance

trophic cascade

changes that occur down the food chain when a keystone species is removed [gray wolf video]

ecosystem engineer

physically change the environment [beavers, elephants]

disturbance

an event that affects environmental conditions rapidly and drastically, resulting in changes to the community and ecosytem

resistance

the ability of a community to remain stable in the presence of a disturbance

resilience

the ability of a community to change in response to disturbance but later return to its original state

primary succession

happens when a new patch of land is created or exposed for the first time —> follows a disturbance so severe that no vegetation or soil life remains

secondary succession

beings when a disturbance dramatically alters an existing community but does not destroy all life and organic matter —> some vegetation or soil life remains and helps shape the succession process

pioneer species

adapted for colonization; first species to arrive in new community [small plants, moss]

fragmentation

occurs when large areas of habitat are divided into smaller, disconnected ones

causes: logging, building roads, agriculture [impacts species that depend on larger territories

edge effects

impact on organisms/communities that results because conditions along the edge of a habitat fragment differ from conditions in the interior

island biogeography theory

explains how the number of species on an island results from a balance between the number added by immigration and the number lost through local extinction

winner species characteristics

- generalists, using many resources/habitats

- geographically widespread

- small, fast-reproducing, and fast adaptation skills

loser species characteristics

- specialists on certain resources/habitats

- limited to small range

- large, slow-reproducing, and needing of stable conditions

extinction

last member of a species dies and the entire species ceases to exist

local extinction

disappearance of a particular species from a given area

background extinction rate

average rate of extinction that occurred before human existence

mass extinction event

large proportion of the world’s species in a very short time due to some extreme and rapid change [earth has 5, almost 6]

major causes of biodiversity loss [5]

1. habitat loss [farming, urban development, deforestation]

2. pollution

3. overharvesting [trees, fishing, poaching]

4. invasive species

   • climate change [fossil fuels and gas emissions]

introduced species

species introduced by human beings form one place to another

invasive species

species that spreads widely and rapidly becomes dominant in a community, interfering with the community’s normal functioning

conservation biology

understanding factors that influence the loss, protection, and restoration of biodiversity [used to develop solutions to habitat degradation and species loss]