You’re ignoring neutral evolution. Why?
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You mean like when I said…?
?
When?
Simply put, “Before.”
No, not like that, you clearly don’t understand it.
What’s that number, Daniel?
Good. Incremental progress! How long before?
Why is diploidy important, and why is it so obviously missing from your understanding of evolution, even your unrealistic description of it as only Darwinian evolution?
How much of the variation on which selection and drift act comes from new mutation? As you said, you need to have some sense of the numbers. You clearly don’t.
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Sir, for the LTEE, it is demonstrating the kind of microevolution I have no issue or debate with, its examples of convergent evolution included. Hence my earlier thread about asking how long it would take, continuing to watch bacteria evolve at the microevolutionary scale but without seeing “macro” changes (e.g., a new, functional organelle I,parting a novel ability) before we could say the macroevolutionaryntheory had been disproven.
I completely agree, as I understand the experiment, that convergence has happened in various manners therein. (Do I recall correctly reading somewhere that the mutation to metabolize citrate happened more than once, independently?) And in these cases, I would completely agree that the pathway must not be particularly difficult if the evolutionary mechanism can stumble upon it not just once, but multiple times.
In other words, the LTEE demonstrates the kind of microevolutionary convergence I would take no issue with if it were suggested among sheep breeders, peppered moths, finches, or the like… that different pathways were discovered that led to say, heavy, shaggy wool, pigmentation, beak shape, or the like.
So in short, I have no issue whatsoever with the general microevolutionary principles, convergent evolution among them. I completely embrace, endorse, affirm everything about basic microevolutionary theory, Lenski’s LTEE among them. And convergence at the microevolutionary level I also fully endorse. But just as proof (and my belief) in microevolution does not convince me it is an adequate explanation for macroevolution, neither does the reality of convergent evolution in the micro scale convince me that it must have happened at the macro level.
I’ve given that more thought, and unless I am completely missing something, I realized it is perfectly expected even from the ID model why changes would be identical at the amino acid level but not at the nucleotide level… please indulge me, and see if I am completely missing something here.
Hypothetically, suppose with me that these prestin genes had been intentionally designed, and artificially imported or copied into both organisms.
If I understand rightly, over the generations, it would not be surprising for genetic mutations to occur and even accumulate in those specific bases where the mutations made no difference to the amino acid sequencing. natural selection only caring about any changes to the protein, not caring what genetic sequence created said protein.
For instance, if a sequence CUG were mutated into CUA, it would make absolutely no difference; the subsequent amino acid sequence, and hence subsequent protein, would be identical, and natural selection would not even take notice. That particular sequence could then experience a further point mutation and arrive at UUA, but again, make absolutely no difference to said organism.
So it seems unsurprising that, in different organisms, an identical protein could accumulate irrelevant mutations due to redundancy in the code, while still preserving the same amino acid sequence. Thus it seems to my amateur and novice understanding that this is exactly why one would expect, even from an ID perspective, to find correspondence at the amino acid, but not genetic, level. Am I completely missing something here?
Hi Daniel - you’re correct that the redundancy of the amino acid code allows for different nucleotides to encode for the same amino acids. These are called “synonymous” mutations.
Consider this, though - only a few amino acids in the prestin gene are convergent for echolocation. There are many more that are not convergent.
Under your hypothesis, if we compare the prestin gene between echolocating whales and echolocating bats, what would we predict for synonymous mutations at amino acids that are not convergent for echolocation? How about when we compare these amino acids between echolocating bats and non-echolocating bats or conversely between echolocating whales and non-echolocating whales?
Under a common ancestry hypothesis, we would expect that these nucleotide sequences between echolocating bats and non-echolocating bats (for example) to match one another much more closely than either would to whales.
And this is what we observe.
So, you would have to adjust your “common design” hypothesis to also include that the designer also designed the synonymous changes at non-selected amino acids to match non-echolocating organisms that appear to be related to the echolocating one, just as common ancestry would predict.
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Please forgive my ignorance, can you point me to what experiments (and what are the general results) that show mutations can lead to increases in intelligence?
Sir,
As mentioned earlier, I take no specific issue with the idea of common descent broadly understood, either by biological reproduction or in some kind of conceptual design descent (as if a genetic engineer extracted dna from one bat, inserted necessary echolocating and other modifications, then cloned the result into a new species). I would assume that most bat species would resemble each other in these manners.
I’d assume that any designer would only import those specific changes necessary to accomplish the necessary purpose, hence the striking molecular convergence. It doesn’t particularly surprise me that the rest of that particular gene in, say, an echolocating bat would more resemble that of another bat rather than that of a whale. No more than I would be surprised if any other part of a bat’s genome more closely resembled that of another bat more than that of a whale.
Or do I misunderstand your observation here?
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