Species Concepts and Molecular Evolution Review

These flashcards cover key concepts related to species definitions, reproductive isolation, speciation mechanisms, and molecular evolution.

Biological Species Concept (BSC)

A definition of a species based on the ability to reproduce and create viable offspring; separate species are reproductively isolated.

Prezygotic Barriers

Reproductive barriers that occur before fertilization, preventing mating or fertilization between species.

Postzygotic Barriers

Reproductive barriers that occur after fertilization, affecting viability or fertility of hybrid offspring.

Allopatric Speciation

The process of speciation that occurs when populations are geographically isolated.

Sympatric Speciation

The process of speciation that occurs when populations are in the same geographical area but become reproductively isolated.

Reproductive Isolation

Mechanisms that prevent species from mating and producing viable offspring.

Dobzhansky-Muller Model

A model that explains how genetic incompatibilities can lead to reproductive isolation between species.

Neutral Theory of Molecular Evolution

A theory which states that most evolutionary changes at the molecular level are caused by stochastic processes rather than natural selection.

Transposable Elements

Segments of DNA that can move or replicate within a genome and can cause mutations or changes in gene expression.

Molecular Clock

A method for estimating the time of evolutionary divergence based on the mutation rates of genes.