Jehu: I would think that this article about how genetic variation within species declines over time to be published in the July 27 issue of Science has interesting implications for a front loading scenerio. The article explains how research by a paleontologist at the University of Chicago shows how (at least in the case of trilobites) when species first emerge they have more variation and as time goes on the variation declines then the species goes extinct.

Yes, I'm inclined to agree that this could have "interesting implications for a front loading scenario." From a systems perspective, I believe it is quite reasonable that evolutionary progression can lead to increased constraints on further change.

"The paper is relevant to the big question of what fueled the Cambrian radiation, and why that event was so singular," said UC-Riverside's Hughes of Webster's study. It appears that organisms displayed "rampant" within-species variation "in the "˜warm afterglow' of the Cambrian explosion," Hughes said, but not later. "No one has shown this convincingly before, and that's why this is so important."
…
The genomic hypothesis offers a second explanation for the decline of within-species variation over time. According to this idea, internal processes in the organism were the key factors. Various developmental processes interact with one another to control the growth and formation of body parts as any organism progresses from egg to adult.

"It's been suggested that early on in evolutionary history, in the Cambrian Period, the degree to which these different developmental processes interacted with each other within the organism was a lot less," Webster said. "As a result, the constraints on what the final organism looked like were relatively low."

Its interesting that Webster came to this conclusion of reduced variation over time while studying trilobytes, with 17,000 known species and which "once were the most common creatures in the world's oceans".

Kazuo Kawano seems to have arrived at a similar observation from his study of the order Coleoptera (beetles), which "contains more described species in it than in any other order in the animal kingdom" (Wikipedia).

You can't fault either for picking cases that lack potential for diversity.

Kawano: The fact that phyla, classes, orders, and families had evolved in the remote past and never evolved again suggests that higher taxa, once evolved as a framework of variation, have stayed unchanged from the time of their emergence to today. The facts and logic indicate that the morphological evolution of multicellular animals has not been a spreading process but a process of diminishing dynamics where the magnitude of evolutionary effects on morphology decreased with time. Evolution is not a process of micro variations accumulating to macro effects but of macro effects preceding micro variations (p. 50).

cs lewis, and the lady who wrote harry potter, should all be shot for their fiction.

Too late for Lewis. He died on the same day Kennedy was shot.

i find nabakov's lolita to be perhaps one of the best books ever written in english.

on the note of the zebra, tiger, elephant, etc……
the answer is rather obviously obvious: get off the high horse, and say hello to hobbes. he never gave calvin more than a rumble tumble now and again, nothing more.

:mrgreen::shock::idea:

I'd pull out my S&W and shoot the tiger in the head, then the elephant.

Anybody who has taken time to read Lewis's noxious pot-boiler "That Hideous Strength" should feel justified in shredding his complete works.

I have no idea what you are talking about. "That Hidieous Strength" is a great book. I recommed it to everybody who reads this thread.

…Except for the bit about Ayn Rand… that was deadly serious.

All you need to save yourself is self-belief, sometimes in the teeth of the all evidence. I'd go and read Just go and read Atlas Shrugged by Ayn Rand and stop worrying about the cliff, zebra and tiger"¦..Didnt you mean "constant angular velocity""¦.Of course, it is also true that you and the zebera are chasing the tiger.

Er, did you realize that was a joke?

Personally I reject Ayn Rand on a couple of fronts: one is that she published several of the most hideously written novels of all time, with characters so one dimensional that it makes the mind reel.

My original comment was mainly intended as a jibe at her preposterously bad fiction, something that only Rand-ist ideologues could truly love.

I might also level the same criticism about C. S. Lewis, whose overt Christianity I have no problem with but whose cloying, twee fiction, wooden characters and asinine plots I find utterly irritating. Anybody who has taken time to read Lewis's noxious pot-boiler "That Hideous Strength" should feel justified in shredding his complete works.

On the other hand, I have no problem at all with J K Rowling, Tolkein and Lewis Carrol, all of whom were/are Christians who delight in expounding their redemptive philosophy through fiction, but all much, much better writers.