On speciation 26 Jun 200922 Jun 2018 The Atavism has some thoughts on speciation in response to a high school teacher’s query. He uses the following nice diagram to indicate what some of the core species definitions mean: It’s neat, and therefore… wrong. By which I mean that given the rule that biological organisms do what they damned well please, sometimes speciation will not involve allele frequency change (but rather reorganisation of the same alleles), and sometimes the new species won’t occupy a distinct niche, and sometimes hybrids remain viable, and sometimes different species do not have “monophyletic DNA” (which I take to be the claim that some of the DNA is unique to that species). Life is unkind … to taxonomists. Ecology and Biodiversity Evolution Humor Species and systematics Systematics
Creationism and Intelligent Design New work on lateral transfer shows that Darwin was wrong 31 Mar 200918 Sep 2017 A new study into the transfer of genetic material laterally, or across taxonomic divisions, has shown that evolution does not proceed as Darwin thought, and that in fact the present theory of evolution is entirely false. Instead, it transpires that lateral genetic transfer makes new species much more like Empedocles‘… Read More
Epistemology Pattern cladism and the myth of theory dependence of observation 4 Mar 2011 A new paper has been published in the History and Philosophy of the Life Sciences, entitled “Pattern Cladism, Homology, and Theory-Neutrality” by Christopher Pearson. Either the journal has done something horrible to the text, or the author doesn’t know the difference between Willi Hennig and William Hennig, or between Gareth… Read More
Administrative What I am doing on my holidays…. 27 Sep 2009 Well, first I lost, or rather British Airways lost, my luggage, so I am living in the same clothes I spent 36 hours on planes in. Unpleasant. But, Jenny and I went to the Accademia Galeria and saw enormous numbers of Medieval and Renaissance paintings. Then to the Piazza San… Read More
Hi John, You are of course right. I should have been more explicit that this is an example of what might happen in one case not ‘the one true path to speciation’ – if you find a universal truth in biology you are almost certainly wrong 😉 The idea was to highlight De Queiroz’s ideas about species concepts as species delimination concepts. (And yes “monophyletic DNA” was my shorthand for species having completely sorted lineages for at least one gene)
Don’t get me wrong – I like the diagram. I was just making a passing observation. It has to do with essentialist definitions failing in biology.
I strongly recommend Speciation By Jerry A. Coyne, H. Allen Orr. It will provide a more technical discussion of the various ways that it can happen, along with some aspects of the way the word means different things in different contexts, and really nothing at all when you look to closely.