Evolution and Natural Selection

Natural selection

The process through which organisms better adapted to their environment tend to survive and produce more offspring.

Gradualism

Theory developed by James Hutton and Charles Lyell suggesting that changes in the earth's geology occur slowly over time.

Fossil record

The preserved remains of ancient organisms that provide evidence for gradual changes over time.

Jean Baptiste Lamarck

Proposed the first major theory of evolution, suggesting that organisms could adapt to their environment and pass on changes.

Charles Darwin

Naturalist who published 'On the Origin of Species' and proposed the theory of evolution by natural selection.

Darwin's finches

A group of bird species that evolved from a common ancestor and adapted to various ecological niches.

Principle of Variation

The concept that there is inherent variability within populations.

Principle of Heredity

The idea that variations are passed down through generations.

Selective pressure

Factors that influence which individuals survive and reproduce in a population.

Comparative anatomy

The study of similarities and differences in the anatomy of different species, providing evidence for evolution.

Genetic polymorphism

The occurrence of two or more variations in a population, leading to genetic diversity.

Speciation

The formation of new and distinct species in the course of evolution.

Allopatric speciation

Speciation that occurs when populations are geographically isolated from one another.

Sympatric speciation

Speciation that occurs when populations evolve in the same geographic area but exploit different resources.

Behavioral isolation

A form of reproductive isolation where different species have distinct mating behaviors.

Temporal isolation

A form of reproductive isolation where different species mate at different times.

Mechanical isolation

A form of reproductive isolation where different species have incompatible reproductive structures.

Gametic isolation

A form of reproductive isolation where sperm and egg are incompatible, preventing fertilization.

Hybrid sterility

A condition where hybrid offspring between two species are sterile and cannot reproduce.