biology exam

Convergent Evolution

A process where unrelated species develop similar traits due to similar ecological pressures.

Inheritance of Acquired Characteristics

Lamarck's theory suggesting that organisms can change traits during their lifetime and pass those changes to offspring.

Natural Selection

Darwin's mechanism of evolution where traits that improve survival and reproduction are favored over time.

Superposition

A principle stating that in undisturbed rock layers, the oldest rocks are at the bottom and newer ones on top.

Vestigial Traits

Reduced or useless structures from ancestors, such as the human tailbone.

Natural Selection vs Inheritance

Natural selection works on existing genetic variation while inheritance of acquired characteristics suggests changes during an organism's life are passed on.

Adaptive Radiation

A rapid diversification of species into different environments.

Directional Selection

A type of natural selection that favors one extreme phenotype.

Genetic Drift

Random changes in allele frequencies in small populations.

Bottleneck Effect

A drastic reduction in population size, leading to loss of genetic diversity.

Founder Effect

When a small group starts a new population, leading to different allele frequencies.

Darwinian Fitness

The ability of an organism to survive and reproduce in its environment.

Gene Pool

The total genetic diversity within a population.

Phenotype

Observable traits of an organism resulting from the interaction of its genotype and environment.

Macroevolution

Large-scale evolutionary changes that occur over geological time.

Microevolution

Small genetic changes within a population, often observable over shorter time scales.

Sexual Dimorphism

Physical differences between males and females of the same species.