Evidence for Evolution and Evolutionary Mechanisms

VOCABULARY flashcards covering the definitions of evolution, selection types, evidence lines, and speciation processes based on Chapters 11, 12, and 13.

Evolution

A genetic change in the overall inherited characteristics of a group of organisms (populations) over multiple generations.

Population

A group of individuals of the same species living in a defined area.

Adaptation (Process)

An evolutionary process by which a population becomes better matched to its environment over time through natural selection.

Natural Selection

The process by which individuals with advantageous inherited characteristics for a particular environment survive and reproduce at a higher rate than do individuals with other, less useful characteristics.

Artificial Selection

Biological evolution for desired traits caused by humans performing selective breeding.

Selective Breeding

The process by which humans determine which individuals with desired characteristics will mate.

Canis lupus familiaris

The scientific name for wolves, which were domesticated into today's dogs approximately $16,000$ years ago.

Fossils

The mineralized remains or impressions of formerly living organisms.

Common Ancestor

An organism from which many species have evolved.

Common Descent

The sharing of a common ancestor by two or more different species.

Homologous Traits

Similar structures in organisms of common descent that were inherited from a common ancestor but may begin to look different over time.

Vestigial Traits

Features inherited from a common ancestor that are no longer useful and may appear as reduced or degenerated parts.

DNA Sequence Similarity

A measure of how closely related two DNA molecules are to each other.

Biogeography of a Species

The geographic locations where a species' fossils are or will be found.

Embryonic Development

The process of how an organism develops from a zygote into its full form at birth.

Evolutionary Mechanisms

The five processes that drive evolution: natural selection, mutation, gene flow, genetic drift, and sexual selection.

Directional Selection

A pattern of natural selection where individuals of one extreme of a phenotype have the advantage over others, such as in the case of the peppered moth.

Stabilizing Selection

A pattern of natural selection where individuals with an intermediate value of an inherited phenotype have the advantage, such as human birth weight.

Disruptive Selection

The least common survival method where individuals of either extreme of an inherited phenotype have the advantage over intermediate forms.

Biological Species Concept

The definition of two organisms as the same species if they can reproduce and have viable offspring.

Speciation

The process by which new and distinct species evolve from a common ancestor.

Allopatric Speciation

Speciation that occurs when a population is geographically separated into different groups by physical barriers like mountains, rivers, or oceans.

Sympatric Speciation

Speciation that occurs when a new species evolves from a single population in the same geographic area without any physical barrier.