Unit 2 test flashcards

Enviromental Bio

Population Ecology

The study of how populations interact with their environment, including factors like birth and death rates.

Population

A number of organisms of the same species that live in a particular area at the same time and can interbreed.

Arithmetic Growth

A pattern of growth where the same number of individuals is added at each generation; not realistic long-term.

Exponential Growth

A J-shaped growth curve where growth accelerates with each generation; often occurs when resources are plentiful.

Population Growth Rate

The percentage of population change per year, calculated by (new population/time).

Doubling Time

The length of time required for a population to double in size, roughly estimated by the formula 70/population growth rate.

Net Growth Rate

Determined by the formula: (Births + Immigration) - (Deaths + Emigration).

Carrying Capacity

The maximum number of organisms an environment can support.

Logistic Growth

A type of growth that occurs when resources are limited, creating an S-shaped curve.

Range of Tolerance

The range of environmental conditions within which a species can survive.

Habitat

The complex environment an organism depends on for survival, including abiotic and biotic elements.

Ecological Niche

The role an organism plays in its ecosystem, including all interactions with biotic and abiotic factors.

Survivorship

The probability of an organism dying during a particular time interval.

Type 1 Survivorship Curve

Species that mostly die of old age.

Type 2 Survivorship Curve

Species that have a constant mortality rate throughout their life span.

Type 3 Survivorship Curve

Species that mostly die at a young age.

Evolution

Inherited changes in a population over time, primarily driven by natural selection and genetic drift.

Natural Selection

The process by which certain traits increase an individual's likelihood of survival and reproduction.

Fitness (Biological)

An organism's ability to produce viable offspring, contributing to the next generation.

Adaptations

Inherited characteristics that enhance an organism's ability to survive and reproduce.

Directional Selection

Natural selection individuals that display a more extreme form of a trait have a greater fitness than those with average or less extreme traits, leading to a shift in the population's trait distribution.

Stabilizing Selection

Individuals with the average form of a trait have the highest fitness.

Disruptive Selection

Natural selection that favors individuals at both extremes of the phenotypic range.

Genetic Drift

Random changes in the frequency of traits in a population due to chance events.

Founder Effect

A change in the frequency of an inherited trait that is caused by a small subset of the population. Type of genetic drift

Reproductive Isolation

Mechanisms that prevent species from interbreeding with others, leading to speciation.

Mass Extinction

A rapid and widespread decrease in biodiversity on Earth.

Background Extinction Rate

The normal rate of extinction for various species, occurring continuously.

Demographic Transition Model

A model that describes population change over time, often linked to modernization and economic development.

Ecological Footprint

The area of land needed to supply resources consumed by a population.

Biocapacity

The ability of an ecosystem to regenerate resources consumed.

Competitive Exclusion Principle

The principle stating that two species competing for the same resource cannot coexist.

Fundamental Niche

The full range of conditions and resources in which a species could survive without competition.

Realized Niche

The actual conditions and resources in which a species exists due to competition.

Niche Differentiation

the process by which species in an ecosystem use resources differently to avoid competition

Coevolution

The process where two or more species influence each other's evolution through reciprocal selective pressures.

Mutualism

A type of interaction in which both species benefit.

Commensalism

A relationship between two organisms where one benefits and the other is neither helped nor harmed.

Parasitism

A type of interaction where one species benefits at the expense of the other.

Predation

An interaction where one organism (the predator) feeds on another organism (the prey).