Cladistics determines relatedness among organisms by counting shared, derived characters: characters that are ________ to taxa descended from a ________.

One school of thought holds that Earth’s organisms ought to be categorized in strict accordance with ______, while another holds that other factors, such as shared physical qualities, ought to be considered as well.

Adaptive radiation is the rapid emergence of many species from a single species that has been introduced to ________.

Living things are classified largely in accordance with degrees of ________.

All species are referred to by a two-part name, the first part of which is a species’ ________.

Under the biological species concept, species members are defined by their ability to ________ with each other in nature.

Name as many intrinsic isolating mechanisms as you can.

The critical factor leading to speciation is reduced ________ between two ________ of the same species.

The mule provides an example of the intrinsic isolating mechanism of hybrid ________.

Two factors always play a part in allopatric speciation: first, the development of ________ and second, the development of one or more ________.

Sympatric speciation is speciation that does not involve ________.