Young-earth theories

So this might sound like a dumb question, but the 'even if they are sitting next to each other' statment makes me wonder if the the snails are 'incapable' of interbreeding because of some physical or preferential impediment; and if they could still interbreed if snail A was artificially inseminated by genetic material from snail B.The distinction might seem trivial, but here's my point: is inability to breed due to some physical mutation - say the snail ejaculates in the wrong spot, whatever- really speciation if the two organisms could reproduce with help - i.e. the sperm from snail A can still create a viable zygote when introduced to the egg of snail B?

Cool. Thanks WK. I agree that conditions exist that allow speciation to occur, but something about this example didn't sit right with me.So which of the following would meet your definition of speciation?1-Sperm from organism A could not create a viable zygote when introduced to an egg from organism B.2- A could create a viable zygote with B, but the resulting offspring would be sterile (e.g. mule).3-A could create a viable zygote with B, but the fertilization success rate between A-B is significantly (noticeably) less than A-A or B-B.This message has been edited by custard, 02-25-2005 06:48 AM

Yes, that makes a great deal of sense.

I see what you mean, but I don't think there really is a 'correct' version - the definition of speciation seems to depend on what type of scientist you are.The strictest definition of BCS does not incorporate the 'in the wild caveat'(from Observed Instances of Speciation): seems to be held by mainly by 'vertebrate zoologists and entomologists.'Then you have phenetic/morphologic species concept, and I still don't really understand which definition botanists prefer.I think the least fuzzy, albeit most restrictive, definition of speciation is the strictest interpretation of BCS.Sure organism A and B may no longer have any 'interest' in breeding (say Canis Lupus and Canis Domesticus - not the greatest example though), and probably wouldn't or couldn't do so in the wild, but under controlled conditions (artificial insemination say) A-B could still produce viable, reproductive offspring.I think this strict interpretation is necessary when debating very literal minded creationists who would simply argue that even though organisms A & B don't reproduce in nature, the still COULD reproduce and thus aren't really seperate species.This message has been edited by custard, 02-26-2005 00:47 AM

Well put Ned. That was the succinct version of the explanation I was striving for.The problem (I believe) for creationists is the fuzziness that TOE advocates have no trouble accepting; AND I think that is why we keep seeing these 'but you have to have faith to believe in TOE' declarations by them because they get frustrated with the haziness of the definitions of things like species and speciation.This message has been edited by custard, 02-26-2005 02:28 AM