Evolution, religion, and ignorance.

[Esquilax]

Possibly. The devil is in the details.

1. What do you mean by "trace its lineage"? If you're speaking of actual observation, than I'm probably on board. If you're referring to inference from differences in existing species, I disagree that that constitutes tracing a lineage.

I'm not even asserting that it's literally happened at this point, just ascertaining that you're on board with the idea that genetic and physiological details play a part in determining species classifications.

Now, as it happens, if you accept that then there are certain things I would point you to, but I have a horrible suspicion that, say, if I show you fruit flies demonstrating this under laboratory conditions you'll object on the grounds that they didn't become dragonflies, or something like that.

2. How do you operationally define "sufficiently different"?

I grant that it's something of a fuzzy line, but given the point of the passage you're responding to I felt safe in going general. Like, I'm sure I don't need to point out how different dogs are from raccoons, or anything like that.

Do you think that all the varieties of dogs come from mutations, or selective breeding of existing variation potential from ancestral wolves? You're assuming mutation, rather than existing variation potential which expressed due to a change in environment. What should be done is to repeat it in a controlled way. Record the genome of the initial population and check subsequent generations to see exactly what happened. That would be pretty good evidence.

I'm not even sure what "existing variation potential" means. It seems like another offshoot of whatever mechanism you think exists that prevents the crossing of species lines, to me. Any variation is evolution, and I'd like to know how you demonstrate and quantify that this is due to some nebulous "potential."

The short time period also works against you. Why don't we see more such change if it's so easy?

That's a complex subject, and it'd be impossible to provide an exhaustive list of things we'd need to contemplate here. I'd also be concerned that you'd accuse me of contradicting myself if I listed one possibility, and then listed another that is incompatible with the first, but was also provided with an understanding that the two wouldn't happen simultaneously within the same case.

To be brief, part of the reason you see such rapid alterations in these lizards is that the entire population was dropped into a new environment, with different selection pressures and its own genetic bottleneck for them to pass through. This population was lucky, in that it managed to oust out its competitor species, but due to the isolation and lack of predators, had few selection pressures to pull them down from the environment. This is a delicate balance that you wouldn't be able to pull off every time; for example, a similar situation occurred when rabbits were introduced to Australia. Since the rabbits had no natural predators there, were able to hybridize with another species of rabbit, and were prolific breeders made more so by the difference in climate, they were able to outpace many native species without any selection pressures to drive changes in the species. Simply put, they were transplanted into an environment for which they were already suited, rather than one that would incite change through necessity.

That said, in other cases we do actually see the same kind of rapid change; if you want an example, just look at the domestication of silver foxes, where some very notable alterations occurred over just a few generations of being bred for passivity.

It's a complex topic, and one I'm not doing justice to in a single forum post. Bear that in mind.

Scientific evidence shouldn't be based on imagination.

However, predictions are often made based on prior gathered evidence in science. That was another one, that could be applied retroactively, and has been; the problem is that you dismiss any connections we find where we haven't directly witnessed every generation in the process.

Given that, I hope you have a couple million years to wait.

It's not my fault that evolution lacks clear definitions for basic terms like species.

And it's not my fault that you seem unable to realize that "small changes accumulating gradually" means "small changes accumulating gradually." What are you after, a dog giving birth to a snake?

How does one falsify a position based on imaginary extrapolation?

Macro-evolution makes predictions that could falsify it; all you'd need to do is find one fossil outside of the expected stratographic layer, and you'd get there. I know you dismiss fossil evidence because we weren't there, but the fact is that this is a way to falsify evolution anyway, and nobody has been able to do so.

Now that I've answered your transparent dodge, let's get back to the issue at hand: how do we falsify your position when you keep bouncing between two answers, heedless of what I'm actually describing?

Seems to be change at the species level to me.

First sentence.

Yes. Neither of those is present above. You say "will," which is closer to "this is definite" than "this is possible."

So either I misspoke, or you misread. I don't care which, but do you now accept that that was not what I was saying?