When two organisms typically do not interbreed with one another, they are considered different species. But what are the reproductive barriers that isolate one population from another? Hear the ...

A rare example of gene incompatibility between two species of budding yeast has been found. This discovery of elusive 'speciation' genes adds to other reproductive-isolation mechanisms operating in ...

Slate takes a break from endless political analysis to tackle a biological question: Can humans have sex with other animals and produce offspring? The answer: "Probably not." Um, "probably"? Oh dear.

"A new species develops if a population which has become geographically isolated from its parental species acquires during this period of isolation characters which promote or guarantee reproductive ...

A new study of interbreeding between two species of howler monkeys in Mexico is yielding insights into the forces that drive the evolution of new species. A new University of Michigan study of ...

Aradus cinnamomeus Panzer, the pine bark bug, is a pest of young Scots pines which exhibits a two-year pattern of periodicity in most parts of Europe. The alternate-year populations live almost ...

Mayr was well known for his championship of the biological species concept and for asserting a predominant role for the geographic separation of populations in the diversification process that gives ...

For decades, scientists, policymakers, graziers and land managers have been locked in a surprisingly high-stakes debate over what defines a dingo. Are these wild canids their own species? Or are they ...