People throw the word species around as if it were a definite unit, but the reality of defining a species is much trickier, and more contentious, than it seems. Biologists have been arguing over the definition of a species since the dawn of humanity, but have yet to come up with a single species concept that works for all types of life. This film explores some of current concepts used across the various fields of biology and covers some of the specific problems they encounter.
May 2011 16:00 min