Listen, it's really very simple. Take a bunch of sheets of paper. Divide them into two separate groups.

Now, fold one sheet once. That's a small, say 1-bit of DNA mutation.
Fold the rest of the sheets in that group. That represents the mutation being spread to the other members of that community (assuming it's selected for. Some are, some aren't. That's why it takes a LONG time.)
Now, fold one of the sheets a second time, in a different direction. That's a second mutation.
Fold the rest of the sheets in that group, again, too. That's the spreading.
Do this a dozen or so times. What you end up with is a bunch of objects, all similar, all having the same original form as, but now also very different from, the objects in the first group (the unfolded bits of paper.)

That's how it works. Massively simplified, of course.

And for another thing, if everything was a mutation of a basic pattern, how do you explain the fact that not everything has the same amount of DNA? Any chromosomes added would be gibberish, basically millions of mutations, and thus many fatal ones would be included. And any chromosomes removed would be deadly, because I seriously doubt that we could afford to loose 2% of our DNA. If it's all mutation, then we'd all (all being all life, not all people) have the same number of chromosomes. Our DNA would just be different variations on a single ancestor, with variables changed, but none added or subtracted.

*smug grin*

Well, not really. I prefer 'Christian' now.

But one thing our R.E. teacher admitted was that the bible was absolutly crystal clear on homosexuality. Not some metephour, or anything like that. Not 'consider the lillies of the field', the bible states that homosexuality is a very evil deed.

He didn't agree, and neither did we, but as proper catholics we must treat homosexuals as evil snake worshippers.

And not have before marriage sex. Or use contraception.

*ahem*

And that happens...

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You know, when Comedy Central asked us to do a Thanksgiving episode, the first thought that went through my mind was, "Boy, I'd like to have sex with Jennifer Aniston."

...

That is...what I meant to say was...Cyclops? What are you talking about? Some childish endeavor that I would never engage in, surely.

*ahem*

As I meant to say, um...oh yeah. Don't you mean *smug mode*, Liam? (And yes, I did try snpp.com. They don't have the guides for that season done yet.)

Omega said: Well, he said some stuff. To be honest, I'm really not sure what you're driving at. What "sharp" division are you speaking of, exactly? You seem to be assuming that evolution works on the level of individuals. It does not. Instead, as First said, it operates on communities. And, over time, all the members of an isolated community are going to share a unique genetic code that will prevent them from interbreeding with members of their old species.

For instance, let's say that...oh, Jennifer Connelly and I live in some freaky beatnik commune. And so, as men and women often do, we have a child. Said child contains a minor genetic mutation. Said child goes off and does same with other members of same commune. Process repeats until minor genetic mutation is shared in the entire commune. New gene proves useful, so it continues to change. Eventually, everyone here becomes a new species. (A spectacularly attractive one, I might add.) How? Because the members of the commune are more closely related genetically than those outside of it. Meaning that I can reproduce with them, even though are genetic codes are not identical. But I can no longer reproduce with outsiders, who have not been able to incorporate ANY versions of this new mutated gene.

Or, in other words, say the gene is A5. I can reproduce with people who have A4 and maybe A3. But not people with A1, and those are the people outside of the commune.

The division of either being able or not able to reproduce with other specimines. See my next example.

I think I see what you're driving at, but it still doesn't work. You're suggesting multiple grades, as opposed to my two; saying that person A could reproduce with person B, and B could reproduce with C, but C could not reproduce with A (please ignore gender). Even if it was possible, it still wouldn't make any difference. B and C would have a child, and their child would inherit B's ability to reproduce with A, thus not creating a different species.

Besides, why are we arguing this? The whole process has been observed in the natural world.

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HMS White Star (your local friendly agent of Chaos and a d*mn lucky b*st*rd:-) )

there are many ways in which mutations might occur, and virtually none of them involve changes to entire chromosomes. (this is why you have FAR more species than there are #'s of chromosomes possible in a cell.)

Yes, the paper is still paper, much as the DNA in our bodies is still DNA. HOWEVER, the SHAPE of it has changed radically, far moreso than the small percentage which our DNA differs from, say, pan troglodytes (a chimp).

"The average human being has about 50-100 mutations (differing them from EITHER of their parents,) of which about 3 may actually matter (they actually change a protein.) If the typical mutation were deleterious, life would go extinct in short order." - parenthetical expressions mine.

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You know, when Comedy Central asked us to do a Thanksgiving episode, the first thought that went through my mind was, "Boy, I'd like to have sex with Jennifer Aniston."

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It's all about the Pentiums, Baby!
"I'm down with Bill Gates, I call him Money for short
I phone him up at home and I make him do my tech support"

Furcula (wishbone) formed of two clavicles fused together in the midline.

Now we start getting on shaky ground. It used to be thought that the possession of a furcula distinguished birds from dinosaurs. Indeed, up until recently even clavicles were few and far between in even theropod dinosaurs (the suggested closest group to the birds and from which the birds evolved - see Ostrom 1976). However, it has been found that theropod dinosaurs did indeed have clavicles (e.g. Bryant &Russell 1993) and they have been found in several species, e.g., Segisaurus, Velociraptor, Euparkeria, Ornithosuchus, Saltoposuchus, Ticinosuchus. Also, Chure & Madson (1996) reported furculae in a non-maniraptoran, allosaurid dinosaur.

It has been found that the clavicles are often small and poorly ossified. This is no surprise, since they are of little evolutionary advantage to your average theropod dinosaur. However, birds too show this variation in ossification, especially amongst the carniates and some parrots, clavicles are reduced or even missing. Therefore the apparent absence of clavicles in some theropod dinosaurs may well be due to poor ossification rather than true absence. However, furculas have been found in some theropod dinosaurs, namely the Oviraptorosauria (Barsbold et al. 1990, Bryant & Russell 1993), for example Oviraptor and Ingenia. Thus furculas do not appear to be diagnostic to birds and certain members of the suggested closest group to the birds now appear to possess furculas so it is a neutral character.