RNR 316 Natural Resources Ecology - Chapter 4: Adaptations to Variable Environments

Vocabulary flashcards covering key terms and definitions from Chapter 4 on adaptations to variable environments in the ecology course.

Variable environments

Environments that vary in time and space; selection favors evolution of variable phenotypes.

Phenotype

The observable traits of an organism resulting from the interaction of genotype and environment.

Genotype-by-environment interaction

G × E interaction; the effect of genotype on phenotype depends on the environment.

Phenotypic plasticity

The ability of a single genotype to produce multiple phenotypes in response to environmental variation.

Phenotypic trade-off

A situation where a phenotype has higher fitness in one environment while other phenotypes have higher fitness in other environments.

Plasticity and homeostasis

Plasticity allows organisms to achieve homeostasis when environmental conditions vary.

Reaction norm

The pattern of phenotypic expression of a genotype across a range of environments.

Acclimation

Rapid, reversible behavioral/physiological adjustment to the environment.

Adaptation

Long-term, genetically determined change; population becomes better suited to habitat.

Isozymes

Different enzyme forms within a species that enable performance across temperatures (e.g., goldfish have cold- and warm-acclimated forms).

Microhabitat

Locations within a habitat that differ in environmental conditions.

Notothenioids

Antarctic fish group that produces antifreeze compounds to prevent freezing.

Antifreeze compounds

Substances produced by some organisms to prevent freezing of body fluids.

Migration

Seasonal movement of animals in response to changing conditions; a plastic behavior.

Storage

Accumulation of fat or caching of food for periods when resources are scarce.

Dormancy

A state of markedly reduced metabolism; includes several subtypes.

Diapause

Partial or complete physiological shutdown in response to unfavorable conditions (common in insects).

Hibernation

Reducing energetic costs by lowering heart rate and body temperatures during winter (in mammals).

Aestivation

Shutting down metabolic processes during hot or dry conditions.

Torpor

A brief period of dormancy with reduced activity and lower body temperature (common in birds and mammals).

Osmosis

Movement of water across membranes from areas of low to high solute concentration.

Transpiration

Loss of water from plants through stomata.

Root-to-shoot ratio

Allocation of biomass to roots versus shoots; adjusts with water availability.

C4 photosynthesis

Modified photosynthetic pathway that improves water-use efficiency.

CAM photosynthesis

Crassulacean acid metabolism; a water-saving photosynthetic pathway.

Albedo

Reflectance of Earth's surface; influences climate.

Weather

Variation in temperature and precipitation over hours or days; describes current conditions.

Climate

Long-term atmospheric patterns measured over decades.

Central place foraging

Foraging where food is brought to a central place; travel time vs. food gain; diminishing benefits with distance.

Optimal foraging theory

Idea that foragers maximize energy gained per unit time by considering where to forage, how long, and diet type.

Handling time

Time required to capture and consume prey; energy gained per unit time = energy divided by handling time.

Diet mixing

Foragers consume a varied diet to obtain all necessary nutrients when single items are insufficient.

Risk-sensitive foraging

Foraging decisions influenced by perceived predation risk; trade-off between reward and risk.

Inbreeding depression

Decrease in fitness due to mating between close relatives because deleterious alleles are inherited.

Hermaphrodite

Individual that produces both male and female gametes and can fertilize its own eggs.

Self-fertilization

Mating with one's own gametes when mates are unavailable; often yields fewer eggs.

Photosynthesis

Process by which sunlight provides the energy to convert CO2 and water into sugars in plants.

Climate drivers

Factors such as changes in solar radiation, ocean circulation patterns, albedo, and topography that shape climate.

Monarch butterfly migration

An example of migration where monarchs move seasonally to winter and summer sites.

Inducible defenses

Predator-induced changes in growth, shape, or behavior that increase prey fitness by reducing predation.

Diet quality

The energetic and nutritional value of food items that influences foraging decisions.

Handling time (foraging)

Time required to capture and consume prey; used to calculate energy gain per unit time.

Predation risk

Danger of being eaten by a predator, influencing foraging choices.

Ecological trade-offs

Situations where improving one trait reduces performance of another due to limited resources.

Water balance adaptations

Strategies to minimize water loss or maximize water uptake (e.g., C4/CAM, root adaptations).