Intimate Partnerships: How Species Adapt to Each Other

These vocabulary flashcards cover the primary concepts of coevolution, interspecific relationships, and endosymbiosis as presented in Chapter 15.

Trophic levels

Feeding relationships among various species within an ecosystem.

Producers

Plants and other organisms that use photosynthesis to convert solar energy into stored chemical energy in organic molecules.

Mutualism

An ecological relationship between species that raises the fitness of both species (positive/positive).

Commensalism

A relationship in which one species benefits but the other suffers no loss of fitness (positive/neutral).

Coevolution

The process of reciprocal evolutionary change between ecologically intimate species driven by natural selection.

Pleiotropic effects

A phenomenon where a single gene has multiple effects on an individual's phenotype.

Negative frequency-dependent selection

Selection where the relative fitness of a phenotype is high when it is rare and low when it becomes common.

Coevolutionary alternation

A process occurring when one species in an antagonistic relationship interacts with several other species over time.

Coevolutionary arms race

Also known as coevolutionary escalation, this is an extreme expression of antagonistic coevolution that can impose high costs on both species involved.

Tetrodotoxin ($TTX$)

A neurotoxin produced in the skin of rough-skinned newts that locks onto nerve cell receptors to cause fatal paralysis.

Attenuated coevolution

A process where an intense antagonistic interaction gradually decreases until each species exerts only weak selection on the other.

Biological control

The intentional release of a natural enemy to attack and manage a pest population.

Virulence

The severity or harmfulness of a pathogen or virus.

Müllerian mimicry

A form of convergent coevolution where two or more toxic or unpalatable species evolve to look alike, reinforcing predator avoidance.

Batesian mimicry

A form of convergent coevolution where a nontoxic or palatable species evolves to mimic the appearance of a toxic model species.

Geographic mosaic

Diversifying coevolution resulting in a wide range of ecological outcomes because selection pressures vary across different populations.

Elaiosomes

Lipid and protein-rich structures on seeds that attract ants to disperse the seeds to their nests.

K-T mass extinction

A mass extinction event occurring approximately $66 \text{ mya}$ that notably impacted mutualistic species like corals.

Endosymbionts

Mutualistic organisms (symbionts) where one species lives inside the body or cells of another species.

Theory of serial endosymbiosis

The theory that eukaryotic cells evolved through a series of events, first acquiring mitochondria and then chloroplasts.