Unit 2: The Living World - Biodiversity

The process by which life-supporting resources, such as clean water, timber, fisheries, and agricultural crops are produced

An indicator that describes the current state of an environmental system

○ Biodiversity ○ Food production ○ Average global surface temperature and carbon dioxide concentration in the atmosphere ○ Human population ○ Resource depletion

The diversity of life forms in an environment

• Ecosystem • Species • Genetic

• A measure of the genetic variation among individuals in a population ○ Populations with a high genetic diversity are better suited to respond to environmental change

• The number of species in a region or in a particular ecosystem ○ Higher species diversity causes more resilience to environmental changes and are more productive ○ Critical environmental indicator

The evolution of a new species

The average rate at which species become extinct over the long term

• A measure of the diversity of ecosystems that exist in a given region ○ A greater number of healthy and productive ecosystems results in a healthier environment overall

• The number of species in a given area ○ Used to measure biodiversity in a given area

• The relative proportion of individuals within the different species in a given area ○ Tells us whether a particular ecosystem is numerically dominated by one species or whether all of its species have similar abundances

• The branching pattern of evolutionary relationships ○ Can be described with a diagram

Evolution below the species level

Evolution that gives rise to new species, genera, families, classes, or phyla

• A random change in the genetic code produced by a mistake in the copying process ○ Mutations can affect an organism’s survival and make their chances better or worse

• The genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division ○ Does not create new genes but brings together new combination of alleles on a chromosome and therefore can produce novel traits

The process in which humans determine which individuals breed, typically with a preconceived set of traits in mind

The process by which the environment determines which individuals survive and reproduce

• The process by which individuals move from one population to another and thereby alter the genetic composition of both populations ○ Alters the frequency of alleles in populations ○ Can bring in genetic diversity to a population that lacks it

A change in the genetic composition of a population over time as a result of random mating

• A reduction in the genetic diversity of a population caused by reduction in its size ○ When a population is reduced, its genetic diversity reduces as well ○ Can causes individuals to be less equipped to face environmental problems, disease, or low fertility

A change in the genetic composition of a population as a result of descending from a small number of colonizing individuals

Values independent of any benefit to humans