ENVS 1308 Lecture 1: Evolution, Species Interactions, and Biological Communities

Vocabulary flashcards covering evolutionary patterns, selection types, tolerance limits, ecological niches, speciation mechanisms, and species concepts from ENVS 1308 Lecture 1.

Acclimation

A physiological or behavioral adjustment occurring within an individual lifetime in short-term response to environmental factors such as heat, light, or drought.

Adaptation

A population-level evolutionary change in which inherited traits become more common across generations because they influence reproductive success.

Directional Selection

A pattern of natural selection in which individuals at one end of a trait range experience higher reproductive success.

Stabilizing Selection

A pattern of natural selection in which intermediate trait values perform best and extreme values are selected against.

Disruptive Selection

A pattern of natural selection in which both extremes of a trait range outperform intermediate values, favoring specialization.

Tolerance Limits

The environmental gradient range that defines where a species can persist, comprising an optimal range, zones of physiological stress, and zones of intolerance.

Niche

The specific conditions, resources, timing, and biological interactions (including physical tolerances, food use, predators, and competitors) that allow a species to persist and reproduce.

Generalists

Organisms that utilize broad resources and tolerate a wide range of environmental conditions.

Specialists

Organisms that perform very well in a narrow ecological niche but may be more vulnerable when that niche changes.

Divergent Evolution

An evolutionary pattern in which related lineages experience different ecological pressures and become increasingly different over time.

Speciation

The evolutionary process in which reduced gene flow leading to independent evolution results in the formation of independently evolving lineages.

Allopatric Speciation

Speciation initiated by geographic separation that reduces gene flow, leading isolated populations to evolve independently under mutation, drift, and selection.

Sympatric Speciation

Speciation occurring within the same geographic area without geographic isolation, driven by reproductive barriers such as behavioral isolation or chromosome-number changes.

Adaptive Radiation

Repeated diversification from one ancestral lineage into multiple descendant species associated with different ecological opportunities or niches.

Convergent Evolution

An evolutionary pattern in which separate or unrelated lineages independently evolve similar traits, forms, or ecological solutions under similar selective pressures.

Morphological Species Concept

A species concept that defines a species based on consistent, observable physical form and structure.

Biological Species Concept

A species concept that defines a species based on interbreeding capability and reproductive isolation.

Ecological Species Concept

A species concept that defines a species based on its occupation of a distinct ecological niche or set of resource uses.

Phylogenetic Species Concept

A species concept that defines a species as a diagnosable cluster of organisms sharing a unique evolutionary lineage history and ancestry.