Lecture 20: Predation, Parasitism, and Disease

These flashcards cover key vocabulary and concepts related to predation, parasitism, and disease as discussed in Lecture 20.

Predation

An interaction in which one organism consumes another, typically resulting in the death of the prey.

Parasitism

An interaction in which one organism (the parasite) lives on or in another organism (the host), potentially harming it and sometimes leading to the host's death.

Antagonistic Coevolution

Reciprocal adaptation between predators and prey, where each evolves in response to the other, often described as an 'arms race'.

Enemy Release Hypothesis

The idea that invasive species experience a population increase in a new habitat because they have fewer natural enemies (predators or parasites).

Latitudinal Gradient in Species Richness

The observed pattern that species richness generally increases as one moves toward the tropics from the poles.

Dilution Effect

A phenomenon where increased host diversity decreases the risk of disease transmission to humans or animals.

Amplification Effect

A situation where the presence of more host or vector species increases the population of disease-causing organisms, raising disease risk.

Life-Dinner Principle

The concept that prey have stronger selection pressures than predators due to the life-and-death stakes of predation.

Direct Life Cycle (of parasites)

A life cycle where a parasite completes its development in a single host species.

Complex Life Cycle (of parasites)

A life cycle that requires two or more host species to complete its development.

Inducible Defenses

Defensive traits that are expressed in response to threats or attacks, such as morphological or chemical changes in prey.

Paine's Sea Star Experiment

A landmark ecological experiment demonstrating that a predator, the sea star Pisaster, maintains biodiversity in rocky intertidal ecosystems.

Mutualism

An interaction between two or more species where all involved species benefit.

Keystone Species

A species that has a disproportionately large effect on its environment relative to its abundance, often crucial for maintaining ecosystem structure and biodiversity.

Mimicry

The evolution of an organism to resemble another organism or an object in its environment, often for defense or to gain access to resources.

Batesian Mimicry

A form of mimicry where a harmless species evolves to imitate the warning signals of a harmful species to deter predators.

Müllerian Mimicry

A form of mimicry where two or more unpalatable or dangerous species share a similar warning signal, reinforcing the avoidance learning of predators.

Commensalism

An interaction between two species where one species benefits from the interaction while the other species is unaffected.