SPECIATION THROUGH ISOLATION

Geographic isolation

form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water

Speciation

A process typically caused by the genetic isolation from a main population resulting in a new genetically distinct species.

What three types of barriers that can lead to reproductive isolation?

Behavioral barriers, geographic barriers, and temporal barriers.

What are the differences and similarities between behavioral isolation and temporal isolation?

Behavioral isolation involves differences in courtship or mating hehaviors; temporal isolation involves differences in the timing of courtship or mating behaviors.

Behavioral isolation

Form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding

Temporal isolation

Form of reproductive isolation in which two populations reproduce at different times

Reproductive isolation

Separation of species or populations so that they cannot interbreed and produce fertile offspring

Why are the flash patterns of fireflies considered to be behavioral isolation?

The flash-pattern mating behaviors of fireflies are not related to the timing of mating, so this is considered behavioral isolation rather that temporal isolation.

How did geographic isolation affect the diversity Darwin observed in Galapagos finches?

The geographic isolation of the finches on different islands mant that each island's environment selected for traits that were beneficial on that particular island. Over time, genetic differences accumulated in the isolated populations, leading to many distinct finch species.

How can reproductive isolation lead to speciation?

If popultations cannot mate successfully with one another, genetic differences may accumulate in the populations. Over time, the populations may become so different that they become different species.