Unit 2 Notes: Biodiversity

Speciation

The process by which natural selection leads to the formation of a new species, often through changes in color or genetic mutations during reproduction.

Extinction

The complete disappearance of an entire species due to environmental changes, forcing species to adapt, migrate, or die.

Endemic species

Species that are found in only one specific area, making them more vulnerable to extinction.

Background extinction rate

The rate at which Earth's species have historically disappeared, typically a low percentage like 0.0001%.

Mass extinction

An event characterized by a significant increase in the background extinction rate, often ranging from 25-95%.

Species diversity

The characteristics of a community, including species richness (number of species) and species evenness (proportion of species).

Ecological niche

The role a species plays in an ecosystem, including its pattern of living and habitat.

Specialist species

Species with narrow, specific niches, often limited to one type of habitat or food source.

Native species

Species that naturally live and thrive in a particular ecosystem.

Indicator species

Species that provide early warnings of ecosystem failure.

Keystone species

Species that have critical roles in an ecosystem, such as pollinators or top predators.