John Whitfield has a blog on the Origin of Species - a post per chapter as he goes.

In chapter 2's entry he covers some of the ground I did in one of my earlier posts - about how Darwin views the definition of species. I particularly noted his comment:

Here's some advice for anyone agonizing over creating a perfect, all-encompassing species concept: chill out. Pretty much any biological category you care to think of has fuzzy boundaries. Genomics is making the concept of the gene more problematic. Colonial, clonal and modular organisms, such as slime moulds, aspen, and the vast underground mycelia of some fungi, make the concept of the individual tricky to pin down. The giant mimivirus blurs the line between viruses and cellular life. There's been a long debate over whether viruses themselves should be classed as living things. And it's proved impossible to come up with a list of properties that unambiguously define life.

This does not mean that terms such as species, gene, individual or life are useless. In many or most cases it'll be obvious whether the thing or group of things you're looking at belongs in a particular category or not.

I shall post, asking for comments on thoughts about the utility of the terms...will at least enlighten me!

On reading The Origin of Species

Is the distinction between 'species' and 'variety' useful? Does it fuel the macro/micro duality?

If we formally regard all organisms as 'varieties', then perhaps the macro/micro misunderstanding would be cleared up.

Darwin notes on p. 105:

A wide distance between the homes of two doubtful forms leads many naturalists to rank both as distinct species; but what distance, it has been well asked, will suffice? if that between America and Europe is ample, will that between the Continent and the Azores, or Madeira, or the Canaries, or Ireland, be sufficient? It must be admitted that many forms, considered by other highly competent judges as varieties, have so perfectly the character of species that they are ranked by other highly-competent judges as good and true species. But to discuss whether they are rightly called species or varieties, before any definition of these terms has been generally accepted, is vainly to beat the air.

What are the advantages of the distinction? Of classifying organisms according to genera, phyla, etc? The question perhaps sounds rather vacuous - of course labelling has utility. It allows communication. But what if the act of labelling things is actually causing a perceived either/or duality where none actually exists? What are the alternatives?

On the definition of "species"

Apparently there are some 18(? must check) definitions for 'species'. The creationist's arguments imply that 'evolutionists' only use one of the definitions - or use the one that suits them at the time...

In the former case, it would be interesting to note any examples of speciation for each particular definition.

In the latter case, well, much the same - but if a speciation event by each of the different definitions can be shown, is that not sufficient to prove that speciation does occur via natural selection?

Things to look up:
1) How many definitions of 'species' or 'speciation' are there (How many does evolution claim? How many do creationists claim?)
2) Examples of speciation under each definition.