BIO 420

Evolution

The process through which species change over time due to genetic variation, natural selection, and heritable traits.

Genetic Variation

Differences in DNA sequences among individuals, essential for evolution.

Natural Selection

The process where individuals with beneficial traits are more likely to survive and reproduce.

Fitness

The proportionate contribution of individuals to future generations, determined by their reproductive success.

Heritable Trait

A characteristic that can be passed from parents to offspring.

Ecological Time

A short time scale (about 10 generations) relevant to population dynamics.

Niche

The role or function of an organism within its environment, defined by its requirements and interactions.

Realized Niche

The actual conditions and resources an organism uses, influenced by biological interactions.

Boundary Layer

The region where fluid velocity changes from mainstream to 0 at the solid surface.

Skin Friction Drag (SFD)

Drag force caused by the friction of fluid moving over a surface.

Pressure Drag

Drag that occurs due to pressure differences between the upstream and downstream sides of an object.

Bernoulli Principle

A principle stating that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure.

Lift

The upward force generated by pressure differences in fluids acting on an object, often important for flight.

Cryptic Coloration

A defense mechanism where an organism's coloration helps it blend into its environment to avoid predation.

fundamental niche

The range of environmental conditions and resources in which a species can persist, including its role in the ecosystem.

Evidence for natural selection

• variable traits

• demonstration that the trait confers a fitness advantage

• evidence that the trait is heritable

specilaization

The process by which a species evolves to adapt to specific environmental conditions or niches, often leading to distinct morphological or behavioral traits.

directional selection

A type of natural selection that favors one extreme phenotype over others, causing a shift in the population's trait distribution.