Kevin de Queiroz

1956 - present

The Species Problem

Kevin de Queiroz is a research zoologist at the Smithsonian National Museum of Natural History in Washington, DC.

In order for me to talk about the next possible species in our lineage, I had to be clear on exactly what I meant by the word "species." Scientists from all related fields have struggled for centuries to agree on such a definition. The debate over what exactly should define a species dates all the way back to the days of Plato and Aristotle. One would think that with modern technology, particularly the ability to study the genomes of living species (and some extinct ones), that this debate would have been settled by now. It hasn't. We still have what is called the "species problem." In our recent history, prominent scientists like Ernst Mayr and Theodosius Dobzhansky have all published their views on this topic. John Brookfield, Professor of Evolutionary Genetics at the University of Nottingham summed it up nicely: “The essence of the ‘species problem’ is the fact that, while many different authorities have very different ideas of what species are, there is no set of experiments or observations that can be imagined that can resolve which of these views is the right one. This being so, the ‘species problem’ is not a scientific problem at all, merely one about choosing and consistently applying a convention about how we use a word. So we should settle on our favorite definition, use it, and get on with the science.”

So that is exactly what I did. Kevin de Queiroz has published what he believes is the solution to the species problem. His definition goes back to fundamental principles that can incorporate multiple factors that others have used to define species. The definition is as follows: "A species is a segment of a separately evolving metapopulation lineage."  I realize that the typical reader will not have any idea what this definition means, but I assure you that I have explained it in the book in easily understandable terms and have applied it to the possible answers.

Click on links to other players in my journey below.