02b - Variation and Adaptation

Variation

Physiological, structural, or behavioural differences between individuals in a population.

Discontinuous Variation

involves distinct categories, cannot be measured over a range, and has no in between features (e.g. blood type).

Continuous Variation

Involves a range of differences without distinct categories, falling within a spectrum (e.g. height, skin color).

Harmful mutations

Mutations that cause death or struggle, resulting in the genes being removed from the gene pool.

Neutral mutations

Mutations that have no effect, allowing the genes to persist in the gene pool.

Advantageous mutations

Mutations that improve survival and reproduction, leading to an increase of the genes in the gene pool.

Adaptation

A characteristic that helps an organism survive and reproduce in its environment.

Physiological Adaptation

Biochemical responses of organisms to their environment (e.g. hibernation lowers metabolism).

Structural Adaptation

Anatomical features that enhance survival (e.g. camouflage, night vision).

Behavioural Adaptation

Habits or actions that enhance survival (e.g. migration, cave-dwelling).

Selective Pressure

External factors that affect the survival or reproduction of individuals in a population.

Example of Selective Pressure

Climate change increasing average temperatures or invasive species colonizing an ecosystem.

Mimicry

A structural adaptation where a harmless species resembles a harmful one for survival advantages.

Example of Mimicry

The Viceroy butterfly mimicking the Monarch butterfly to avoid predation.

English Peppered Moth

An example of evolution where colour variations were influenced by pollution, affecting survival rates.