Topic 2 - Envi Sci

Evolution

The process by which species change over generations through competition and natural selection.

Adaptation

The acquisition of traits that allow a species to survive in its environment.

Acclimation

An individual organism’s immediate response to a changing environment.

Genetic Traits

Inherited traits that enable species to live successfully in their environment.

Natural Selection

Process where better-adapted individuals pass their traits to the next generation.

Mutations

Changes in DNA sequences that can be inherited by offspring.

Limiting Factors

Environmental factors that restrict where species can live, such as temperature or nutrients.

Critical Factor

The single factor in shortest supply relative to demand that determines where a species lives.

Tolerance Limits

The minimum and maximum levels of an environmental factor within which a species can survive.

Habitat

The physical place or environment where an organism lives.

Ecological Niche

The role of a species in a community and the environmental factors determining its distribution.

Generalists

Species that can tolerate a wide range of conditions or resources.

Specialists

Species with narrow ecological niches, such as pandas or saguaros.

Speciation

The development of new species through adaptation and genetic change.

Allopatric Speciation

Speciation that occurs when populations are geographically separated.

Sympatric Speciation

Speciation occurring within the same geographic area.

Directional Selection

Evolutionary shift toward one extreme of a trait.

Taxonomy

The study of the classification and relationships of organisms.

Binomials

System of naming species using Scientific or Latinized names (genus and species).

Species Interactions

Relationships such as competition, predation, and symbiosis that shape communities.

Competition

Organisms competing for limited resources like energy, space, or nutrients.

Intraspecific Competition

Competition among members of the same species.

Interspecific Competition

Competition between members of different species.

Predator

An organism that feeds directly on another living organism.

Predation

Interaction where one organism eats another; influences population balance.

Symbiosis

Close and long-term relationship between two or more species.

Mutualism

Symbiotic relationship in which both species benefit.

Commensalism

Symbiotic relationship in which one species benefits and the other is unaffected.

Parasitism

Symbiosis where one organism benefits (parasite) and the other is harmed (host).

Endosymbiosis

One species living inside another species.

Ectosymbiosis

One species living on the surface of another species.

Keystone Species

A species that has a disproportionately large effect on its environment or community.

Community Properties

Characteristics like productivity, abundance, diversity, resilience, and stability.

Primary Productivity

Rate at which solar energy is converted into chemical energy by producers.

Abundance

The total number of organisms in a community.

Diversity

The number of different species, ecological niches, or genetic variations present.

Ecological Structure

Spatial distribution of individuals and populations within a community.

Constancy

Lack of fluctuation in composition or function of an ecosystem.

Inertia

The resistance of a community to change or disturbance.

Renewal

The ability of a community to repair itself after a disturbance.

Edge Effects

Changes in population or community structures at the boundary between two habitats.

Ecotone

The boundary or transition area between two biological communities.

Closed Community

A community sharply divided from its neighbors.

Open Community

A community with gradual or indistinct boundaries where species overlap.

Ecological Succession

The gradual process of change and replacement of species in a community.

Primary Succession

Colonization of bare land by living organisms where none existed before.

Secondary Succession

Development of a new community after a disturbance in an existing one.

Pioneer Species

The first species to colonize new or disturbed environments and can withstand a harsh environment with few resources.

Disturbance

Any force that disrupts species diversity, abundance, or community structure.

Disturbance-Adapted Species

Species that survive or thrive in disturbed environments, such as after fire.

Introduced Species

Species brought into a community that may alter its structure or balance.

Climax Community

The community that developed last and lasted the longest.

Robert MacArthur

A graduate student at Yale and proposed that the more complex and interconnected a community is, the more stableand resilient it will be in the face of disturbance.

Behavioral Isolation

When two identical species live in similar habitat but have differ mating calls.

Geographic Isolation

When the habitat are far enough apart that population were genetically isolated; they couldn't interbreed with populations in the ither habitat.

G. E. Hutchinson

The American limnologist who, thirty years later, proposed a more biophysical definition of niche. According to him, every species exists within a range of physical and chemical conditions such as temperature, light levels, acidity, humidity, or salinity. It also exists within a set of biological interactions such as predators and prey present, defenses, or nutritional resources available.

Charles Elton

British Ecologist who defined the concept of niche in 1927. According to him, each species had a role in a community of species, and the niche defined its way of obtaining food, the relationships it had with other species, and the services it provided to its community.