Ch. 3 AP Environmental Science (Evolution, Biodiversity, and Population Ecology)

co-evolution

long term reciprocal process in which two or more types of organisms repeatedly respond through natural selection to the other's adaptations

convergent evolution

unrelated species having similar characteristics as a result of adaptation to certain environmental pressures

Biosphere

All the parts of the planet that are inhabited by living things; sum of all earth's ecosystems

Endemic

A disease that is constantly present to a greater or lesser degree in people of a certain class or in people living in a particular location

Population

A group of organisms of the same species in a given area

Species

A group of organisms so similar to one another that they can breed and produce fertile offspring

Ecosystem

A specific biological community and its physical environment interacting in an exchange of matter and energy.

Phylogenetic trees

Also called cladograms, a treelike diagram that represents the history of divergence of species or other taxonomic groups of organisms

Adaptive trait

Any heritable trait that enables an organism to survive through natural selections and reproduce better under prevailing environmental conditions

Extinction

Disappearance of a species from all parts of its geographical range

Alfred Russell Wallace

English naturalist who proposed, independently of Charles Darwin, the concept of natural selection as a mechanism for evolution and as a way to explain the great variety of living things

Charles Darwin

English naturalist. He studied the plants and animals of South America and the Pacific islands(Galapagos), and in his book On the Origin of Species by Means of Natural Selection (1859) set forth his theory of evolution.

Disruptive selection

Form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle

Directional selection

Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

Stabilizing selection

Form of natural selection in which the entire curves area begins to form in the middle. Favors intermediate types of the species.

Bottleneck effect

Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.

Mutations

Random errors in gene replication that lead to a change in the sequence of nucleotides; the source of all genetic diversity

Allopatric Speciation

Speciation due to organisms of a species being separated by geographical barriers so that eventually they become so different that they cannot interbreed.

Sympatric Speciation

Speciation that occurs within one area - some factor other than geographical separation has prevented free interbreeding between members of the species.

Generalists

Species with a broad niche who are able to live in a large variety of habitats or use a wide variety of resources.

Specialists

Species with a narrow niche and thus having very specific requirements to survive in their ecosystem.

Niche

The full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions

Evolution

The genetic changes in populations of organisms through generations by means of natural selection.

Habitat

The place or set of environmental conditions in which a particular organism lives.

Speciation

The process by which a new species evolves from a prior species, the most basic process in macroevolution.

Natural Selection

The process by which traits that enhance survival and reproduction are passed on more frequently to future generations than those that do not, thus altering the genetic makeup of populations through time.

Artificial selection

The selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits.

Biodiversity

The variety of organisms in a given area, the genetic variation within a population, the variety of species in a community, or the variety of communities in an ecosystem

community

a set of different species living together in a common area

divergent evolution

the accumulation of differences between groups which can lead to the formation of new species

fossil record

the cumulative body of fossils worldwide

adaptation

the process of traits that lead to better reproductive success being passed on throughout generations to evolve in a population

ecology

the study of interactions between organisms and between organisms and their environments