Speciation and Macroevolution

These flashcards cover key concepts related to speciation, macroevolution, and reproductive barriers.

Speciation

The creation of new species.

Macroevolution

The evolutionary components involved in the process of speciation.

Microevolution

Change in allele frequency in a population over time.

Biological species concept

Individuals are members of the same species if they can interbreed and produce fertile offspring.

Reproductive Isolation

The existence of biological factors that prevent interbreeding and the production of viable offspring among different species.

Pre-zygotic barriers

Barriers that prevent mating or fertilization of egg, thus occurring before the zygote stage.

Post-zygotic barriers

Barriers that occur after fertilization, affecting the viability or fertility of hybrid offspring.

Allopatric speciation

Speciation that occurs due to geographic separation of populations.

Sympatric speciation

Speciation that occurs without geographic isolation.

Polyploidy

A type of speciation mechanism where errors in meiosis lead to offspring with multiple sets of chromosomes.

Adaptive Radiation

Periods of evolutionary change marked by the formation of many new species.

Founder effects

Genetic drift that occurs when a small number of individuals establish a new population.

Mass Extinctions

Significant events where over 50% of species go extinct, often tied to environmental changes.

Punctuated equilibrium

A model of evolution where long periods of stability are interrupted by short periods of rapid change.

Gradualism

The model of evolution that suggests species change slowly over time through gradual accumulation of small changes.