Species and reproductivity

My creationist opponent is arguing to show him where a species of something not only produces a non reproductive variant of itself, but a somehow fundamentally different version of itself in some way. Is there an example of this? Where they become geographically separated and are reproductively isolated?And if I read his response about dogs correctly, he seems to want to lump all kinds of critters in the dog "kind." Is there a good counter argument to this type of classification?

quote:

---

I think the way science is trying to use that "speciation" as proof requires that we now furhter define speciation. Maybe "Micro Speciation" and "Macro Speciation" (which we've never...ever...EVER seen!)

​

Dogs, still make dogs, even though they can't reproduce with each other...they may make wolves, hyenas, dingos, whatever...

​

STILL A DOG, folks!

​

Show me something along those lines (where a species of something not only produces a non reproductive variant of itself, but a somehow fundamentally different version of itself in some way), and then we can talk of the possiblity of macro evolution.

​

Until then, it's still just a stretch of the imagination to think all life came from a single organism somewhere in history.

---

Thread moved here from the Proposed New Topics forum.

Hyena females have a long genital protrusion called a "pseudopenis." And in fact, it looks a whole lot like a hyena's penis.That's not supposed to be a "fundamental" difference from canines? Hell, what does that even mean, anyway? What are the "fundamentals" of dogs? I'm pretty sure a pseudopenis isn't in the dog spec sheet.This is species Platonism - the idea that all individuals are variations from some basic, rigid animal "blueprint" - at its worst. If this guy isn't going to speak English - that is, if he's making up his own definition of the word "species" - why bother talking to him?This message has been edited by crashfrog, 06-19-2004 07:43 PM

Here is an exciting example published last year - though I'm sure your opponent will say a "snail is an snail": The researchers witnessed a speciation event in a closed population they were studying, a single gene mutation changed the shell pattern of a snail, and the constraints of the new shell shape prevent the snails with the two types of shells from aligning their genitals to mate. But, the old-shelled snails could mate with the old-shelled, and the new-shelled could mate with other new-shelled snails.Thus snails with the shell-changing mutation are reproductively isolated from the ones without the mutation - even if they are sitting next to each other in the same pond.Geographical isolation is not required for reproductive isolation - another example is different species of crickets that could mate based on reproductive biology, but never do because their song pattern (mating behavior) doesn't match.I think the snail example powerful: Humans witnessed it, it is based on a single gene mutation, that mutation prevents mating between those with and without the mutation (reproductive isolation), and the shell pattern is visibly different (morphology difference).The problem is - to a creationist, a snail is a snail is a snail (is sometimes a slug...)

When your opponent stated "science is trying to use that "speciation" as proof", what did they mean by [that "speciation"]?Was a specific example being used?

Yeah, who the fuck knows how they classify organisms? Do they, even? Is a panda a bear, or is it a racoon? Are giant pandas and red pandas two different "kinds", even though they're both in the panda "kind"?Who the fuck even knows?

I realize you were being rhetorical, but:Coincidentally, one of the very few things I've read at AIG had to do with bears: Bears are apparently a "kind." Any animal with 'bear' in its name is part of that kind, descended from one pair of Ark bears. Apparently, that pair had genes for various coat patterns and thicknesses, overall body size, dietary differences, thick stomach linings, webbed paws, and insect sucking muzzles segregating in their genomes. I wonder what bears looked like before the flood? A pretty heterogeneous bunch, I would guess...

Tell your creationist friend to think for a moment. If species did not give rise to species that were very closely related to them (none of this dogs giving birth to fish nonsense), then the fossil record--and the current biosphere--would look totally different, wouldn't it? You most certainly would not see a nested hierarchy. And since a nested hierarchy is what evolution predicts--due to common descent-- then what your friend is going on about cannot be an accurate portrayal of evolutionary theory. In other words, dogs giving rise to organisms closely related to dogs is EXACTLY what evolution requires in order to explain the patterns of diverity of life over time.KCThis message has been edited by KCdgw, 06-21-2004 12:17 PM

Thanks everyone for your input. It helps much in my understanding and my responses.Another claim he his making is that he "sees no other other way to proceed as macro-evolution cannot be supported objectively. Therefore it would be impossible to show it did not actually happen (objectively)."I understand that micro/macro and are subjective and arbitrary terms that biologists tentatively agree upon, but if it isn't objective, how do you demonstrate it so? I don't quite understand this.This message has been edited by outblaze, 06-22-2004 04:39 AM