Darn. This is about bugs. I thought they found 27 new species of moonbats.

I would be interested in seeing a daddy longlegs with jaws bigger than its body.

The allegory of the cave has never seemed more appropriate.

This is why I can't take the definition of "species" all that seriously. How do they know that these spiders, centipedes, etc., are really distinct from those in the neighboring room? It's all based on superficialities and opinion, combined with a desire to be able to say "I found and named a new species!"

When taxonomy finally becomes a real science, with the definitions based on impartial and measurable standards established before the fact (like,say, with actual DNA samples), we are going to see a lot , if not most, species suddenly disappear.

Just what we need, more kinds of 'scorpion-like' creatures. Can't they find something new that's good to eat? Like a fast growing shellfish that tastes like a meatball sub or something?

I'm also a bit shocked to learn pill bugs have livers, as I had always assumed that their insides consisted of bug juice.

Raoul: There was a mind-bending NPR story this morning--apparently some rainbow trout swim out to the ocean and grow really big, and are referred to as "steelheads." There is absolutely ZERO genetic difference between them and the ones who stay in the streams. Based on parenthood, you can't tell what a fish will be. Given a young fish, you can't tell what it will be as an adult. They interviewed a somewhat exasperated "scientist" who maintained that rainbow trout & steelheads are COMPLETELY different. The relevance is that steelhead numbers are declining, and so some environmentalists want to invoke the Endangered Species Act. As I said, it was mind-bending...

b. I'm pretty sure I read that fish will continue to grow as long they live.

Raoul: If the definition of species were based only on DNA, the entire fossil record would be rendered irrelevant. Of course, the modern, behavioral, interbreeding population definition suffers the same defect.

Posted by: jd watson at January 20, 2006 4:30 PM

Creationists used to make a lot of fuss about the lack of intermediary fossils between species. What didn't dawn on them was that a big reason for this so-called 'lack' was that naturalists would start with the species definitions, and then debate furiously about which category to put new fossils in, when they didn't quite fit one or t'other.

In fact, most of the 'species' on this planet blend into each other. For example, there are some 20,000 defined species of orchid, but it takes an obsessive orchid fan to tell them apart, and obsessive orchid fans are always arguing with each other.

To you and me, there's only orchids. Species are incredibly difficult to define, and for the most part, it's pretty arbitrary.

Humans just like categorising things. The definitions are ours - nature just keeps bubbling along - it doesn't care a damn about nice clean species divisions.

One day, it's going to smack one of the scientific geniuses on Bros Judd right between the eyes that this fact is evidence for darwinism.

"nature keeps bubbling along"
Great observation, but don't understand how it bears on Darwinism. Of course there is evolution, but that doesn't say much about Evolution.

jd:

Aw, let's cut Brit some slack here. Sometimes you have to allow these guys their flights of poetic fancy. "Nature keeps bubbling along" is just Brit's way of saying that the fact that there are millions of little icky things each different from all the other little icky things proves darwinism. It's sort of the materialists' equivalent to "All Things Bright and Beautiful".

If there's a continuum, then come out and say it, and stop pretending that it's possible to classify, with certainty, every little bug into it's own little ever subdividing taxonomic pigeon hole.

Again, if there were an objective measurement system, we could state that Bug A is 12.44 kilodarwins different from Bug B, while at the same time only 1.3 mililysenkos separate them, so therefore they are definitely not the same species.

Just wait until Edison wants to put a solar generating plan out there.

jdkelly:

Many of those who oppose darwinism tend to the view that God interferes to create new species.

Of course, for this claim they rely on other people to define species for them. Since they do no fieldwork, prefering to hone their biological expertise from comfort of the armchair or the pulpit, they rely on the scientifically-literate for both the discoveries and the taxonomy.

Thus, we are treated to the sight of these Great Skeptics of our age crossing the sea of knowledge by hitching a piggy-back ride on the scientist, until such time as they might find an opportunity to drown him. Unfortunately, what they actually find is that they've gone too deep into the waters to go back.

Thus, we are treated to the sight of these Great Skeptics of our age crossing the sea of knowledge by hitching a piggy-back ride on the scientist, until such time as they might find an opportunity to drown him. Unfortunately, what they actually find is that they've gone too deep into the waters to go back.

Hell hath no fury like a materialist who confronts believers who actually think science has important things to say. It throws the poor dears terribly and puts them off their biscuits.

You've got to admit it was good though, Peter. It was after the style of Lou Gots.

Tell you what though, I just took a stroll down the Gloucester Road, stopping for a singularly tasty Linconshire sausage in a bun. A beautiful, sunny crisp English winter morning. And now I'm off to play golf with an old mate. Bloody lovely.

Yes, it was good. You are the Coleridge of the materialists. :-)

I don't get it. Is asking that scientists behave like scientists too much to ask? To have them live up to their own standards, especially when they use their subjective work to impose their beliefs on the rest of us? (As in the Endangered Species Act.) This smacks of the "chickenhawk" argument (does geology fieldwork give one standing? probably not) used in defense of Darwin's Holy Writ.

Raoul: don't feel bad. Hardly anyone gets it, even though it's easier than say, mathematics.

Taxonomy is a very useful discipline for all sorts of reasons, but don't allow it to confuse you about how evolution works.

Back in those distant days when we thought we were engaged in a debate on darwinism on BrosJudd - talk about naive! - those of us defending it recommended that those opposing at least took the trouble to read the basic popular explanatory material on the topic. By gradual agreement, we even narrowed it down to one essential: Ernst Mayr. Of course, none of 'em did, apart from a bit of quote-mining from the intro by Orrin, otherwise we'd have moved beyond this.

Ernst Mayr's lesson 1 for understanding evolution: Population Thinking. In other words, stop thinking of species in terms of Platonic forms.

The creatures of this world live in the form of reproductively interactive populations of genetically unique individuals. The names of the 'species' are imposed by humans for their own purposes of classification.

In the evolutionary path to the modern horse (equus), one of the 'stages', circa 45 million years ago to 35mya, was the evolution from orohippus to epihippus.

But what does that mean? If you're thinking in terms of Plantonic forms, there must have been a last orohippus giving birth to a first, brave new epihippus, and this 'speciation moment' must have been something earth-shattering and profound (perhaps requiring the gamma rays of God, who knows?)

But that's not how nature works. The names 'orohippus' and 'epihippus' are invented by men to help them identify approximately where in history a fossil fits. They are not a Platonic type of which actual creatures are imperfect copies.

If we had all the bodies of all the populations of hippus 45mya-35mya and could lay them out in a long line by age, sure we could draw a line somewhere and say "here oro endeth and epi beginneth". But what would that exercise amount to? It would be useful for stacking the bodies on shelves, but would say nothing about the creatures. The line would be arbitrary, and there would be fierce debates about which side of the line actual individuals went.

Creatures live in populations of unique individuals. Divergence happens if populations become reproductively isolated from each other - in other words, if there is no gene flow between them - and they face different selection pressures. Humans came along afterwards to decide what species to call them.

Sometimes its easy and we all agree. "That's an elephant and that isn't". Sometimes it's not at all easy, eg. the 20,000 species of orchid.

What's amusing is the way that the Great Skepics on here haven't twigged - because they didn't understand Mayr's first lesson - that their scoffing at the controversial subject of taxonomy, and their scoffing at darwinism - are fundamentally contradictory scoffs.

Brit:

Back in those distant days when we thought we were engaged in a debate on darwinism on BrosJudd...

Are you sure you don't mean "Back in the days when we were trying to enlighten the forces of ignorance around here and they violated natural law by resisting us..."

I do trust you realize the point of this thread is not to defend platonic forms but to note that the gaps and weaknesses in the darwinian theory of speciation between genotypes are fudged and diverted by using identical language to include mutations within species. Those of us who have read our Mayr understand that clearly.

How is it fudged?

Once you get into population thinking, the problem of speciation is no longer a problem.