Lots of answers can work here but first I’m curious about the experimental evidence for the idea that erosion can drive complex canyon formation.
Equating the erosion process driving canyon formation with the selection process putatively driving complex adaptations is like comparing apples and oranges.
Is this worthy of a new topic?
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Sure, it could be useful to have a topic about why the comparison to canyon formation is a perfectly good metaphor whenever someone asks whether there is “experimental evidence” for any process that is thought to last longer than the tenure of modern humanity.
Yes, true. But the timescales involved, and the a priori improbability of the particular outcome we see before us is what is relevant here. Of all the ways a body of water and erosion could shape a landscape, we end up with the exact particular structure we call The Grand Canyon. What are the odds?
And we can’t go back in time to re-create the events that formed it. We are forced to infer from known causes that this a priori extremely unlikely, highly contingent geological formation is what resulted, and that the forces and durations and so on all were just right so as to produce this specific result:
We could do a “waiting time problem” for the Grand Canyon. How long would we have to wait on average, for a period of erosion starting with some arbitrarily picked geography, to produce our exact Grand Canyon? There are so many OTHER ways it could have played out.
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No, as far as organisms with huge population size and small generation time are concerned, it is not a good metaphor.
Assume for the minute that the scientific consensus view of evolution is correct:
How long do you think some sufficiently complex adaptation (sufficient for you to call it one) would take to evolve, and on what within evolutionary theory specifically are you you basing that estimate?
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If you are suggesting that such organisms should yield “complex adaptations” in the tenure of a human lifetime (or even of all of human history), then you are so spectacularly ignorant of evolution and biology that you should pick up an undergraduate textbook. I will try to explain why your comment is so outlandish and why it makes you look bad.
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The context was “the idea that selection can drive complex adaptation.” I think that both @Rumraket and I expect that you will not be clear about what you mean by “complex adaptation” but we both can provide some great examples of interesting and complex adaptations produced by selection fast. My favorite is the story of the domestication of teosinte – but every story about domestication (esp. of crops) is a narrative of selection driving complex adaptation. The only way to deny this is to [discard intellectual integrity and then] tell us that “complex adaptation” means something like “growing wings for powered flight.” Is that your plan? I hope not, because…
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…if so, you are talking about evolutionary processes that are known to unfold over millions of years. (The Grand Canyon started forming about 5 million years ago. It’s a young geological feature, but it took millions of years to take shape.) I hope it’s obvious why only an ignorant fool would think it clever to challenge “experimental evidence” of the drivers of adaptation or erosion. That person either doesn’t know anything about adaptation and erosion, or is being dishonest.
I hope I’ve been somewhat clear. Please give these things more thought than you have so far. Your challenge about “experimental evidence” is either an easily-met challenge, which should make you reconsider your reading habits, or a dishonest one, which should make your reconsider your conduct.
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Further examples of a long term process …
Here’s a shot down South Bass canyon, looking at Noth Bass canyon on the other side:
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I’ve been there!
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So, since we’re talking about evolution here, that means they’re closely related, since they’re both flowering plants in Rosid?
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Some few comments.
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it takes an average of 10^20 organisms for malaria parasites to develop resistance to chloroquine through a modestly complex adaptation. On the other hand, it took probably less than 10^11 organisms to develop the numerous complex adaptations responsible for morphing terrestrial pig-like ancestors to fully marine dolphin-like whales like Basilosaurus. Are we supposed to believe that the mechanism explaining the former transition adequately explains the later? If you think it is the case, then please ponder the astronomically huge difference there is between 10^20 and 10^11.
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I am pretty sure that we have experimental evidence that water can erode soils at a certain rate. Given that, it is straightforward to extrapolate that this phenomenon can dig canyons over long periods of time according to an arithmetic law. The situation is very different for complex adaptations requiring coordinated mutations whose probability of occurrence obey a geometric law.
Yes.
You didn’t say ‘please’, but I did that, anyway. Those numbers are different by a factor of a billion. What’s your point?
Is it? Which arithmetic law would that be, specifically?
Do they? What geometric law would that be, specifically?
Do you have a citation for that?
Do you have a citation for that?
Depends on what you mean by “mechanism.” If you mean what scientists mean, which is genetic variation that is subject to selection and drift, then yes, all informed people believe that the mechanisms are the same. But all informed people also know that an adaptation like drug resistance is simpler than the changes associated with new body plans and systems.
Neither number, even if accurate, is relevant to any consideration of whether we have experimental evidence of selection leading to complex adaptation. To toss out those numbers is to reveal deep ignorance or (and I hope this is not the case) duplicity.
BS.
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These took only a few hundred to a few thousand generations:
A LOT of morphological change happens by a few mutations. Consider how much dogs have changed from their ancestors, with a small handful of mutations.
Plasmodium falciparum has a genome size of ~23 megabases and a mutation rate of ~1 - 10 × 10-9, which means you find a mutation in roughly 1 out of every 40, to 1 in every 400 individuals.
Mammals typically suffer dozens to hundreds of mutations pr. individual pr generation. Many of them are rather large-scale rearrangements or insertions due to transposons.
You simply cannot compare plasmodium falciparum to mammals in that way, and you can’t extrapolate the rarity of “solutions” to chloroquine resistance to the “rarity” of mutations that produce morphological change.
These extrapolations from chloroquine resistance you ID guys like doing are ridiculous. They don’t work. The math doesn’t work.
All adaptations are not the same. Some really are accessible from inordinate amounts of positions in sequence space (increasing the amount of hormone expressed for example, can have effects of many parts on the body simultaneously). And there are many more ways of increasing the amount of some hormone (duplications can increase dosage, better binding by transcription initiators can increase the dosage, reducing function in repressors can increase the dosage, etc. etc.), and several different hormones can have similar effects.
In this way many more loci can contribute to changing body morphology and are therefore way more accessible to evolution, while a particular transporter interacts with a particular drug perhaps only through a few specific residues that epistatically interact.
You REALLY need to stop falling for this silly appeal to chloroquine resistance that people like Behe and Bechly keep doing when trying to undermine macroevolution. They just aren’t the same thing. They don’t work in the same way.
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Depending on who you ask, that ‘modestly complex’ adaptation may be the need for 9 specific simultaneous mutations across 3 different genes. That’s absurdly specific. Far more specific than, say,
Which are actually, broadly, independent of one another. So yeah, anyone with a basic understanding of how any of the relevant systems work would recognize that, if chloroquine resistance in Plasmodium is possible, then cetacean evolution should be relatively easy.
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Did Behe count out 10^20 organisms in a lab? Have a separate control group feeding off volunteers absent drugs? Reasonably enough - no. That is the point to this thread, that much science legitimately involves extrapolating processes which are known, to larger scales which cannot be accommodated on a bench or completed in human lifespans. Many creationists of all sorts just throw out the “were you there?”, but are eager to embrace such when it suits their purpose.
Frankly, I place little stock in Behe’s malarial calculations, so do not consider it relevant to whale evolution. Both the inputs for number of organisms and the selective pressure in regards to treated human hosts are guesstimates at best.
Besides, maybe Basilosaurus did not adapt but just lost their piggy information.
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True Scotsman fallacy
Never heard of it. Do you perhaps mean the No-True-Scotsman fallacy? The fallacious dismissal of counter-examples by shifting what should reasonably be assumed to have been a description to being an actual definition?
If so, that’s not what sfmatheson did here either. They merely observed that scientifically literate individuals generally understand that evolution happens by the same processes, generally speaking, between even lineages as vastly distinct as malaria parasites and whales. No counter-example has been presented, so no fallacious shift of that statement from a descriptive to a defining one could commence. Therefore, no No-True-Scotsman fallacy was committed.
What it looks like, rather, is that you are (incompetently, one ought add) hunting for a flaw to latch onto, meanwhile completely ignoring any and all actual points everyone raised regarding your idle expression of personal incredulity.
And, for the record, nobody overtly called that expression an argument from incredulity fallacy either. Because everybody found it more interesting or fun or respectful to actually address what you said instead. Could also be that they had something substantive to say about it. If only you did, too…
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Show your work.
My rough calculation based on numbers from Wikipedia is that with Indohyus around ~50mya and Basilosaurus ~40mya, there were 10my between them. If the generation time was ~5 years, that’s 2m generations - so for your 10^11 to be correct, the average global population of cetaceans throughout that time would have to be less than 50,000.
Since the current population of a single species of whale (orca) is about that size, your estimate is ludicrously low.
Ok. I’ve pondered the difference between a ludicrous overestimate and a ludicrous underestimate, and I see no problem whatsoever.
So show your work.
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