Lecture 16: Evolution III: Macroevolution

These flashcards cover key concepts related to speciation and macroevolution as discussed in the lecture.

Speciation

The process of species formation through various mechanisms.

Allopatric Speciation

Speciation that occurs when a physical barrier separates populations.

Sympatric Speciation

Speciation that occurs without geographic separation, often through reproductive isolation.

Prezygotic Barriers

Mechanisms that prevent mating or fertilization between species, occurring before zygote formation.

Postzygotic Barriers

Mechanisms that reduce the viability or reproductive capacity of hybrid offspring after fertilization.

Morphological Species Concept

Defines a species based on shared measurable traits distinguishing them from other species.

Biological Species Concept

Defines a species as a group of organisms that can interbreed and produce fertile offspring.

Phylogenetic Species Concept

Defines a species based on unique ancestry and evolutionary relationships.

Hybrid Zone

An area where closely related species meet and interbreed, resulting in hybrid offspring.

Polyploidy

The condition of having extra sets of chromosomes, often occurring due to cell division errors.

Founder Effect

A phenomenon where a small group becomes isolated from a larger population, affecting genetic diversity.

Reproductive Isolation

Mechanisms that prevent different species from mating and producing fertile offspring.

Natural Selection

The process through which organisms better adapted to their environment tend to survive and reproduce.

Gene Flow

The transfer of genetic material between populations, affecting genetic diversity.

Ecological Isolation

A prezygotic barrier where species occupy different habitats and do not meet.

Temporal Isolation

A prezygotic barrier where species breed at different times.

Behavioral Isolation

A prezygotic barrier where differences in mating behaviors prevent interbreeding.