Geographic, Behavioral, or Temporal Isolation

Geographic

A type of isolation in which two populations become separated by a physical barrier such as a canyon, river, lake, preventing the two populations from interbreeding.

Behavioral

A type of isolation in which two populations with complex courtship displays or rituals become different enough that they no longer respond to the other's actions.

Temporal

A type of isolation where two species whose ranges overlap have different periods of sexual activity or breeding seasons.

Geographic

Albert's squirrel and the Kaibab squirrel are distinct subspecies that live on opposite sides of the Grand Canyon. They were once one species, but now differ significantly, including fur coloring.

Temporal

Of the seven species of cicada, threee follow a 17-year mating cycle, while four follow a 13-year mating cycle. In regions where their geographic range overlaps, their emergence coincides once in every 221 years. This last happened in North America in 2015 and will not occur again until the year 2236.

Temporal

The American toad and Folwer's toad live in the same area. However, the American toad mates in early summer while Folwer's mates in late summer.

Behavioral

The females of two species of fruit fly, Drosophila melanogaster and Drosophila simulans, release slightly different mating hormones called pheromones, which are used to attract mates.

Behavioral

The flashing pattern of the firefly is used to attract the opposite sex. Female fireflies only flash back and attract male fireflies who first signal them with a species-specific pattern of light.

Temporal

In the Great Lakes region of North America, gray wolves and coyotes are similar species but do not mate because their breeding periods occur at different times of the year.

Geographic

Tradescantia ohiensis, a plant also known as bluejacket and its relative, T. subaspera have similar reproductive mechanisms but do not mate, as one species lives in sun while the other lives in shade.