AP Environmental Science: Natural Disruptions, Adaptations, and Ecological Succession

Vocabulary practice flashcards covering natural disruptions, climate proxies, mechanisms of evolution, speciation, and terrestrial and aquatic ecological succession.

Periodic disruptions

Natural disruptions that occur regularly, such as the daily cycles of day and night or the daily and monthly gravitational effects of the moon on ocean tides.

Episodic disruptions

Natural disruptions occurring somewhat regularly, such as repeating cycles of high and low rainfall that occur every $5$ to $10\text{ years}$.

Random disruptions

Natural disruptions that occur with no predictable pattern, such as volcanic eruptions or severe hurricanes like Hurricane Ida.

Resistance

A measure of how much an ecosystem disruption can alter or affect the existing flows of energy and matter.

Resilience

The rate at which an ecosystem returns to its original, pre-disturbed state following an environmental disruption.

Foraminifera

Marine micro-organisms with species-specific temperature preferences, whose fossilized dominance in sediment layers allows scientists to infer historic ocean temperatures when those sediments were deposited.

Ice core greenhouse gas sampling

A method of climate reconstruction where ancient ice cores are dated and melted, releasing trapped atmospheric air bubbles to measure historical greenhouse gas concentrations.

Carbon dioxide and temperature relationship

A historical correlation where increased $CO_2$ enhances the atmosphere's capacity for warming, and warmer global temperatures subsequently trigger the oceans to release more $CO_2$.

Intermediate Disturbance Hypothesis

The hypothesis stating that ecosystems experiencing intermediate levels of disturbance sustain higher species diversity than those subjected to either frequent, high-intensity disturbances or infrequent, low-intensity disturbances.

Evolution

A change in the genetic composition of a biological population over successive generations of time.

Microevolution

Evolutionary change occurring below the species level, specifically within an individual population.

Macroevolution

Evolutionary change on a large scale that gives rise to novel species, genera, families, classes, or phyla.

Artificial selection

The process in which humans deliberately determine which individuals reproduce based on a preconceived set of desirable phenotypic traits, such as breeding wild mustard (Brassica oleracea) into cabbage, broccoli, and kale.

Natural selection

The process by which the environment determines which individuals survive and reproduce based on fitness, such as predatory fish preferentially eating larger amphipods so that only smaller individuals survive to reproduce.

Random evolutionary processes

Mechanisms that alter the genetic composition of a population over time through changes unrelated to individual differences in fitness.

Mutation

An occasional random mistake occurring during the DNA copying process that produces a permanent alteration in the genetic code.

Gene flow

The process whereby individuals migrate from one population to another, altering the allele frequencies and genetic composition of both populations.

Genetic drift

A change in the genetic composition of a population occurring over time strictly as a result of random mating events.

Bottleneck effect

A drastic reduction in population size caused by an event that severely curtails genetic variation in the surviving group.

Founder effect

A change in the genetic composition of a population that results from descending from a very small number of colonizing founder individuals.

Allopatric speciation

The formation of new species that occurs when biological populations become geographically isolated from one another, preventing gene flow.

Sympatric speciation

The evolution of one species into two distinct reproductive species occurring within the same geographic area without physical isolation.

Genetically modified organisms (GMOs)

Organisms produced by isolating genes from a donor species with a desirable trait and inserting them into another target species of plant, animal, or microbe (e.g., Bt cotton engineered with Bacillus thuringiensis genes).

Atlantic Cod commercial fishing adaptation

A case of rapid anthropogenic evolution in Gadus morhua, which evolved to reach sexual maturity at a significantly smaller body size and younger age due to intense fishing pressure.

Ecological succession

The predictable, orderly replacement of one ecological community or group of species by another over time.

Primary succession

Ecological succession taking place on newly formed or exposed surfaces devoid of soil and vegetation, such as glacial retreat zones, cooled volcanic lava, or bare rock.

Pioneer species

Hardy early colonizers in primary succession—such as algae, lichens, and mosses—that survive on bare rock with little to no soil and break down rock minerals with organic matter to begin soil formation.

Mid-successional species

Plant species that follow pioneer organisms; they are typically adapted to open, sunlit conditions and capable of growing in thin, nutrient-poor soil.

Secondary succession

The sequence of ecological changes occurring in disturbed terrestrial habitats where the vegetation has been cleared but the underlying soil remains intact, such as in abandoned agricultural fields.

Climax community

The historically defined final and relatively stable ecological stage in the process of ecological succession.

Aquatic succession

The gradual ecological transition of open water bodies, such as glacially carved basins or ponds, as they slowly accumulate sediment and decomposing organic matter, become progressively shallower, and eventually convert into terrestrial ecosystems.

Keystone species

A species that exerts disproportionate control over the structure and diversity of an ecological community relative to its total abundance or biomass.

Indicator species

An organism whose presence, absence, or abundance reflects specific environmental conditions or health metrics within an ecosystem, such as air-pollution-sensitive lichens.