Final Unit 2

Population ecology

How populations interact with their environment, including birth, death rates, and immigration/emigration.

Population

Number of organisms of the same species that live in a particular area at the same time, capable of interbreeding.

Arithmetic growth

A pattern of population growth where the increase is constant over time, adding the same number of individuals at each generation.

Exponential growth

A J-shaped growth pattern where growth accelerates with each generation, often occurring when resources are abundant.

Carrying capacity

The maximum number of organisms that an environment can sustainably support.

Doubling time

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

Net growth rate

Calculated as the growth rate equals (Birth + Immigration) - (Death + Emigration).

Logistic growth

A realistic growth model where population increase slows as it approaches carrying capacity.

Range of tolerance

The range of environmental factors within which a population can survive.

Survivorship types

Type 1: most die old; Type 2: equal mortality across ages; Type 3: most die young.

Adaptive evolution

When species become better suited to their environment over time, typically through natural selection.

Non-adaptive evolution

Evolution that does not necessarily lead to improved adaptation, influenced by factors like genetic drift.

Artificial selection

The process by which humans breed plants and animals for desired traits.

Natural selection

The process where certain traits become more common in a population because those traits confer a survival advantage.

Biological fitness

The ability of an organism to produce viable offspring, reflecting survival and reproductive success.

Predation

An interaction where one organism (the predator) hunts and eats another organism (the prey).

Mutualism

A symbiotic relationship where both species benefit from the interaction.

Reproductive isolation

Mechanisms that prevent members of different species from interbreeding.

Founder effect

Type of genetic drift that occurs when a small subset of a population establishes a new population.

Ecosystem

A biological community of interacting organisms and their physical environment.