Introduction to Environmental Science - Unit 2 Review

Comprehensive vocabulary flashcards covering biodiversity, ecosystem services, island biogeography, ecological tolerance, natural disruptions, evolutionary adaptations, and ecological succession based on environmental science lecture notes.

Genetic Diversity

The variety of genes present within a single species.

Species Diversity

The variety of different species present within an ecosystem.

Ecosystem Diversity

The variety of distinct ecosystems found within a specific region.

Ecosystem Resilience

The capacity of an ecosystem to withstand or recover from disturbances, such as natural disasters or human activities, while maintaining its essential functions and processes.

Specialist Species

Species that possess narrow ecological niches and specific habitat requirements, making them typically the first to die when an ecosystem is altered or destroyed.

Ecosystem Services

The direct and indirect benefits that humans derive from ecosystems, divided into provisioning, regulating, supporting, and cultural services.

Provisioning Services

Ecosystem services that supply material goods necessary for human survival and economic activity, including food, freshwater, timber, and fuel.

Regulating Services

Ecosystem services that maintain environmental balance by moderating natural processes, such as climate control, disease regulation, water purification, and pollination.

Supporting Services

Fundamental ecological processes necessary for the production of all other ecosystem services and biodiversity, including nutrient cycling, soil formation, and primary production.

Cultural Services

Non-material benefits obtained from ecosystems, encompassing recreational, aesthetic, spiritual, and educational values.

Island Biogeography

The study of the ecological relationships and distribution of species on islands and isolated habitats, focusing on variables such as island size, distance from the mainland, immigration rates, and extinction rates.

Endemism

The ecological condition of a species being native and uniquely restricted to a specific geographic area, found nowhere else in the world.

Adaptive Radiation

The evolutionary process by which a single ancestral species diversifies into multiple distinct species, each specialized to occupy a different ecological niche.

Founder Effect

The loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population, often driving rapid evolutionary divergence.

Resource Partitioning

The division of limited environmental resources by coexisting species into distinct ecological niches to minimize direct competition.

Ecological Tolerance

The range of abiotic conditions—such as temperature, moisture, and salinity—in which an organism or species can survive, grow, and reproduce.

Acclimation

The short-term, reversible physiological adjustment made by an individual organism in response to changes in its environment within its lifetime.

Adaptation

A long-term, heritable genetic trait that arises over generations through natural selection, enhancing a population's survival and reproductive success in a given environment.

Geological Time

The extensive scale of time spanning millions to billions of years, used to contextualize historical Earth processes, climatic shifts, and mass extinction events.

Directional Selection

A mode of natural selection that favors phenotypes at one extreme of a trait distribution, shifting allele frequencies in a consistent direction over time.

Stabilizing Selection

A mode of natural selection that favors intermediate phenotypes over extreme variations, reducing phenotypic variance and maintaining the status quo.

Disruptive Selection

A mode of natural selection that simultaneously favors individuals at both phenotypic extremes while selecting against average traits, potentially producing two distinct forms.

Sexual Selection

A form of natural selection where certain traits increase an individual's likelihood of securing mates and successfully reproducing.

Genetic Drift

Random fluctuations in allele frequencies within a gene pool from one generation to the next, exerting particularly pronounced evolutionary effects in small populations.

Structural Adaptation

A physical or anatomical feature of an organism that enhances its survival, such as the thick insulating fur of a polar bear.

Behavioral Adaptation

An action or behavioral pattern performed by an organism that increases its fitness, such as the seasonal migration of birds to escape harsh winters.

Physiological Adaptation

An internal systemic or metabolic process that increases an organism's survival, such as the water-retention mechanisms of camels in arid conditions.

Intermediate Disturbance Hypothesis

The ecological concept stating that intermediate levels of disturbance maximize species diversity by preventing dominant competitors from excluding other species without causing catastrophic mortality.

Ecological Succession

The predictable, sequential replacement of community structure and species composition in an ecosystem over time following a disturbance or initial colonization.

Primary Succession

Ecological succession that begins in a barren environment entirely devoid of pre-existing vegetation and soil, such as bare rock exposed by volcanic lava or newly formed sand dunes.

Secondary Succession

Ecological succession occurring in an environment where a previous community has been disrupted or cleared by an event like a wildfire or flood, but intact soil remains.

Pioneer Species

Hardy, fast-growing organisms capable of colonizing barren or severely disturbed substrates, initiating the process of soil formation and ecological succession.

Climax Community

The stable, mature, and diverse ecological community reached at the final stage of succession, dominated by slow-growing and highly competitive species.

Keystone Species

A species that exerts a disproportionately large impact on community structure and biodiversity relative to its abundance, such that its loss drastically alters the ecosystem.

Indicator Species

An organism whose presence, absence, or population health provides early warnings or reflections of environmental quality due to its heightened sensitivity to environmental changes.