On this episode of ID the Future, David Boze interviews Casey Luskin about a 2012 study published in Nature that claimed that scientists can predict the number of species that will develop within a clade. Such forecasts of speciation are based on the amount of living space available and the prominence of sexually selected traits. However, many of the differences between “species” are quite trivial; what constitutes one species as separate from another when there are no fundamental distinctions?