APES Unit 3

Specialist Species

Species that thrive in specific, narrow environmental conditions with specialized traits.

Generalist Species

Species that can thrive in a wide range of environmental conditions and utilize a variety of resources.

Ecological Niche

The role of a species within its environment, including food acquisition, habitat, and interactions with other species.

K-selected Species

Species that produce fewer offspring but invest significantly in raising them, typically thriving in stable environments.

R-selected Species

Species that produce many offspring with little investment in each, often found in unstable environments.

Survivorship Curve

A graph showing the number of survivors in a population over time and how survival likelihood changes at different life stages.

Carrying Capacity

The maximum number of individuals an ecosystem can support based on available resources.

Overshoot

When a population exceeds its carrying capacity, leading to resource depletion.

Die-off

A sharp decline in population size often resulting from overshoot and resource scarcity.

Density-dependent Factors

Factors affecting population growth that depend on population size, including competition and disease.

Density-independent Factors

Factors influencing population growth regardless of size, like natural disasters.

Total Fertility Rate (TFR)

The average number of children a woman is expected to have during her lifetime.

Replacement Level Fertility

The TFR required to replace the population without growth, typically around 2.1 children per woman.

Malthusian Theory

The idea that populations grow exponentially while resources grow linearly, leading to potential scarcity.

Demographic Transition

The transition of a country from high birth and death rates to low birth and death rates as it develops.

Type I Survivorship Curve

Characterized by high survival rates in early and middle life, with a steep decline in old age.

Type II Survivorship Curve

Characterized by a constant mortality rate throughout an individual's life.

Type III Survivorship Curve

Characterized by high mortality early in life but those that survive early stages tend to live longer.

Biotic Potential

The maximum reproductive capacity of an organism under ideal conditions.

Environmental Resistance

Factors that limit population growth, keeping it below its biotic potential.