This episode is really going to do what it says on the tin- discuss the question of how many species there are in the world. This might seem a simple question, but a simple answer has eluded the scientific community for some years now. On the show today, I'm going to go through some of the methods past research has used to answer this question and what figures they came up with.

Sources for this episode:

NOTE- at one point I mention seven taxonomic levels, but I should have said six.