Celebrating Darwin – what is a species?

It may well turn out that Darwin’s own somewhat vague answer is actually better than some overdefined answers today.

No offense to Ernst Mayr, but it does seem that reproductive isolation may be too limiting of a definition. ANY purely reproductive definition may be too limiting. Perhaps, to riff on Richard Dawikins’ “The Selfish Gene,” it’s a case of a taking a gene’-s eye view of an organism-level issue.

I agree with Darwin that we can’t always define something like “species” as precisely as we might like. Perhaps, per Dan Dennett this time, evolutionary biologists have been practicing “greedy reductionism” here, not just reductionism.

In a somewhat related issue, evolutionary biologists are working to determine just how robust the evolutionary tree of life is.