Ernst Mayr defined a biological species as a

The impact of a large meteorite with Earth would have most likely caused mass extinctions by

If a sheep and goat are mated, their offspring dies as an embryo. This is an example of ________ reproductive isolation.

A tetraploid (i.e., four sets of chromosomes) plant species is typically ________, whereas a plant species with three sets of chromosomes is typically ________.

In the Grand Canyon, in the southwestern United States, there are many species of squirrels, including the Albert squirrel and a “subspecies,” the Kaibab squirrel (isolation is not complete, according to the biological species definition by Ernst Mayr). The two populations of squirrels can interbreed to produce fertile offspring, but the populations exist on different portions of the rim of the Grand Canyon, separated by the canyon and the Colorado River. This is an example of ________ speciation.

In systematics, a group of organisms consisting of a common ancestor and some, but not all, of its descendents is defined as a

A flowering vine plant, Gelsemium spp., includes two separate species that formerly occupied a large, common habitat area, and currently occupy overlapping areas in the southeastern United States. Gelsemium sempervirens and Gelsemium rankinii have reproductive isolation, which has allowed them to exist as separate species due to ________ speciation.

Postzygotic reproductive isolation prevents

The type of reproductive isolation in which offspring are infertile because their chromosomes cannot align correctly during meiosis, due to a different number of chromosomes being inherited from each parent is

The scientist given credit for devising the two-word scientific naming system is