Humans have a penchant for organizing. We like order. This need for organization certainly drove Karl Linnaeus, a Swedish naturalist, to published the first catalog of life, the Systema Naturae, in 1735. He devised the framework we still use in our taxonomy.

In the last post, we explored the challenges of recognizing species. New knowledge forces us to re-examine our understanding of the limits of variation of species. We regularly gain or lose species on our life lists as former species are divided into two or more new species or others combined into a single species.

Taxonomists do have methods for defining a species. The problem is that there is more than one method and the different approaches do not always get to the same conclusion!