A little proof of Evolution

I agree. Creationists cannot deny that natural selection can drive small scale changes in populations, therefore they tend to accept it. And then define microevolution to be that degree of evolution they cannot deny. One could have easily predicted a creationist's reaction to this story.

Variable beak sizes already existed in the species and the shorter ones were selected for as they increased the bird's probability of procreation.

~Ulrika~

I never heard this stated before but obviously that is the case. Thanks for articulating it so well.

~Ulrika~

The only problem with this, and it's something I never really read a good answer to, even in The Beak of the Finch, is that the other sizes of beak weren't drasticly different enough to alter survival. As I recall, the differenc between a long beek and a short beek worked out to like one extra peck to crack open a shell. That alone shouldn't be enough to cause an evolutionary change, particularly not over a couple hundred years.

Always willing to help out

Differences in beak sizes usually have more to do with the ability to reach a food source, such as nectar within a flower, rather than pecking open a seed. Also, studies have shown that even minor variations with only a small degree of benefit can quickly become the dominant trait in a population.

This was the specific focus of the books research in that reguard.




Right, I grok, but it seems too fast for so minor a difference to rise to prominence without some factor that I'm not seeing.

That's a spin.

There is a very specific and easily definable partition here, between evolution due to mutation and evolution due to spread of existing genes. Different mechanisms.

It's perfectly reasonable for someone to draw the line there. Less reasonable to blur the distinction and try and say that _this particular article_ (no evidence of adaptive mutation) provides any support for macroevolution (which requires adaptive mutation).

From the Science article, again "'This study,' he adds, 'will motivate researchers to go into the field and see if they can document other examples of character displacement in action.'"

Which means, I suspect, that a shift in population due to an adaptive mutation has never been documented.

--Alvin

I mean, of course, in the before-and-after manner of this study.

Which would be demonstrably false. This is seen all the time, for instance in bacterial resistence. And the Nylon Bug. Not to mention the work with Drosophila. In many cases the specific mutations that were ultimately selected can be traced.

And you are still missing the big picture. The genetic variation that was being selected from came about via mutation. But, as is always the case, mutation precedes selection. All evolution works the same way: mutation, recombination and gene flow increase the genetic variabilty of a population; while natural selection, sexual selection and genetic drift reduce that variation. All the while, allele frequencies are shifting, causing the phenotype to vary. Over longer periods of time you get reproductive isolation between geographically separated populations, resulting in diversity.

It's all the same thing.

Now this is an interesting issue.

Just like wishing for more wishes from the genie, you'd think evolution would like to develop a way to speed up evolution. Sex is certainly one example (did I just derail the thread again?).

Mightn't there be others? What if the stress response were negatively coupled to fertility somehow?

--Alvin

Yeah, I had second thoughts as soon as I wrote that. But something in this study is ground-breaking, or he wouldn't have made the statement he did. And this study does not deal with evolution by mutation.

"Seems too fast" isn't exactly quantifiable. It is just a statement of incredulty. Perhaps it does, but how does that compare to what a biologist might expect. I know that there has been work showing how quickly a trait with even a small benefit can proliferate in a population, it seems that now i'm goign to have to try to dig that up. But the numbers are very surprising.

Never underestimate a scientist's willingness to exaggerate his accomplishments. Stephen J. Gould made a career out of it.

Your arguments are too ready at hand. That's one problem with this thread: people responding to what they wish other people had said, instead of what was actually said.

Address this one statement, please:

The article in the OP (which does not even claim to demonstrate adaptive mutation) does not provide evidence for macroevolution (which requires adaptive mutation).

That's really all Kevn was saying.

I'm still holding him the winner in this exchange.

--Alvin

As noted earlier, I agree that this paper does not disagree with what most creationists already accept.

My problem merely stems from the mistaken notion that there is a real boundary between micro and macroevolution. And that is what I was replying to. A study that shows the effects of natural selection, still makes an assumption that the genetic variation being selected from was generated by other evolutionary mechanisms, such as mutation. A creationist may disagree with this, and that is how they justify a real distiction. However, to a biologist, there is no distinction, it is all the same process.

There IS a natural, mathematical boundry.

The number of chromosomes in the organism's genetic code.

You add a new chromosome, and you almost always kill the offspring. At best, you make the offspring infertile.

How can you expect to have major changes when the number of chromosomes MUST change, and not only that, but the chromosomes are different sizes, so you can't just Xerox an extra chromosome in there and call it good.

I built that in to prevent the very kind of thing you're talking about.

Sure, some of this can be manipulated in a laboratory, but if you HAD to do this all via random chance, the few billion years that the Earth is thought to have been around isn't long enough. It'd have to be more like 6x10^23 years. That's just a rough figure, of course. One estimate put that figure much higher... enough zeroes to fill a page in a paperback novel.

Now you will you all stop teaching hearsy against me, or do I have to sick Jimmy Swaggart on your collective asses?

I don't remember anyone saying that the article did demonstrate macroevolution, though it's possible someone did. As I recall, it was Kevn who first raised the topic of macroevolution.


Except that he got it all wrong when he said:
"Micro-evolution is nothing more than adaptation. It's a trait that suggests a creator. There was no new DNA created, the information for the large beaks was already there."

1. Nothing in evolution "suggests" a creator unless you want to see one there. Natural phenomena can just as easily be interpreted without such an explanation.
2. "New DNA" is not technically "created" - Kevn is completely ignoring the fact that genes mutate and provide a source of genetic diversity. Kevn's choice of words make it sound like some completely new sequence springs out of thin air by magic, and that's not what happens.

You can declare him the winner if you wish, but I don't think he knows enough about the topic to win anything.

Kevn attempts to use Evolution to back up a different argument
ROFL

Okay, Kevn's name wasn't mentioned, but did anybody expect that he wouldn't post within five minutes?

Kevn, stating only what we have all agreed: that the findings of the article don't provide support for macro evolution.

Juro, claiming that it does. We're only at post #4. The claim was repeated several times. There is a reason for this wide-spread misconception, to wit:

This is deceptive. There is a very real distinction between evolution resulting only from the spread of existing genes and evolution resulting from adaptive mutation. Saying that they are the same because they interact with each other is like saying that mentos and diet soda are the same thing.

And the former alone cannot explain the origin of species.

This is especially amusing then, because he's wrong again. The eye will adapt to any change in the color of ambient light within minutes. It's why light bulbs appear white even though they are much yellower than the sun.

If it's evolution, it's the same sort of adaptive mutation which created the Human Torch.

No points one way or the other. It's also true that nothing in evolution suggests a creator if you want to _not_ see one.

Okay, one point to the pro-evolution team.

If you're saying that the more time he spends in the thread, the worse his score gets, I wouldn't venture to disagree. However, this particular time he made a few early points and then struck a good subsequent balance. Your team made some mistakes, too, and relied on faulty logic. Balance still to the opposition.

Really. Start a new thread and get away from this bird thing.

--Alvin.

Alvin, are you the official forum scorekeeper? I'm someone who finds the topic endlessly fascinating and every time I participate in these discussions I learn something new. I'm not out for points, I'm out for discussion.

Note that I haven't mentioned the bird article once in any of my posts until now. It was interesting, but the weight of evidence in favor of evolutionary theory is so huge that one article on beak length isn't going to explain much.


Genetics are not the easiest field to grasp - for either side. But it would also not be true that genetic drift and mutation are mutually exclusive. Random genetic drift occurs constantly, from generation to generation. Mutations do as well, though how meaningful those mutations are will depend on the environmental conditions and adaptive demands of the moment (a mutation which might be harmful or neutral in one circumstance could well be beneficial in different circumstances -- this is exactly the core of the problem with Behe's "Black Box" idea).

The two events are not the same but they both exist and they both have their influences on evolution. Mutation without Genetic drift might result in bizarre, genetically unstable descendants. Genetic drift with no mutation would result in biologically stagnate, ill-adapting organisms that go extinct very quickly. Evolution requires them both.

Me too. This is the smartest group of people I've ever found on a discussion forum (and you are one of the smartest). I am learning a lot as well.

The reason I framed this discussion as a debate is that without upholding the highest standards of logical reasoning, the facts (which are legion, occasionally at issue, and often seemingly contradictory) will inevitably lead to the desired conclusions.

If I give the round-earth types more grief than the flat-earthers, it's just because I expect more from them.

But that's just me. I'm not an official anything.

Me too. This is the smartest group of people I've ever found on a discussion forum (and you are one of the smartest). I am learning a lot as well.

The reason I framed this discussion as a debate is that without upholding the highest standards of logical reasoning, the facts (which are legion, occasionally at issue, and often seemingly contradictory) will inevitably lead to the desired conclusions.

If I give the round-earth types more grief than the flat-earthers, it's just because I expect more from them.

But that's just me. I'm not an official anything.