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Author | Topic: What is the mechanism that prevents microevolution to become macroevolution? | |||||||||||||||||||||||
Philip Member (Idle past 4750 days) Posts: 656 From: Albertville, AL, USA Joined: |
Creationists deny that small genetic changes can accrue over time.
Actually, *small genetic changes* (hair color, anatomical size, etc.) are tolerated by most YECs, as per NS. Only beneficient chromosomal mutations are viewed as unpalatable, except those science-hyped "hot-spot mutations" ... *mutations* that seem (to me) *built-into* prokaryote genes (A.K.A. ... just another form of NS). Fortunately, many YECs don't expect to see such raw chromosomal mutations in nature that are really beneficial, ... any more than they would expect to see computer programs evolving by coding accidents, program-flip-flipping, re-combinant operating system *mutations*, or similar choatic events. Unfortuantely, macro-ToE theories DO require *unusual yet chaotic* chomosomal mishaps (not a few). Such *freak-miracles*, "hopeful-monster" theories, etc., seem to require a great deal of pseudo-faith, I think some here would agree. Evo-Science seems to require true-faith that mutational-hypotheses can be proven. Beneficial Mutations (proper) in nature (if there be such a thing): have they ever really been proven, AT ALL? I suppose we'd be better off to debate what a beneficial chromosomal mutation REALLY is. A great oxymoron? a mega-science-paradox? A giant fluke of nature? Spontaneous generation? Etc. (OFF TOPIC: Not all *devout-YECs* require YECism to mathamatically support the Bible, the Flood, etc. Even while scientists vainly *prove* mega-evolution, the Christian-YEC would hope somewhat beyond this *backyard-universe*, anyway ... i.e., for sin-redeeming-love. He/she might continue to observe Biblical chronologies as symmetries of time more than equations of time. ... like the periodic-table of elements, octaves of sound-frequencies, light-spectrums of color, and/or other symmetries of nature) (Archer ... My wife is from TaiSan, beautiful country over there) DISCLAIMER: No representation is made that the quality of scientific and metaphysical statements written is greater than the quality of those statements written by anyone else.
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Brad McFall Member (Idle past 5061 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
One reason they may be intransigent on this point is because we have not even the tools to discover the predicates responsible for formal and normal restrictions on what species groupings (in and out of biogeographic homology) can be rationalized to show where coincidentally the first figure of its truth rotates.
Logic will prevent it if it exists. I feel fairly confident in this assement based on a limited purview of the vertebrates(that I have). It seems like this should be true as the issue of hoxology wends it way in another 100 yrs. You are a clever poster but I have seen like you before on-line.
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qed Inactive Member |
I have no idea why Cheetahs are such a popular creationist pick. They are living proof of how fragile a species becomes when evolution is halted by an extreme population bottleneck, resulting in a limited gene pool. African Cheetah population was only reduced to hundreds. Taking this to the next level the tiny gene pool
caused by God's flood would make us all a lot less diverse than cheetahs (or more likely dead). Interestingly the cheetah population of today has an exceptionally high mutation rate. Evolutions reaction against a shallow gene pool???? (don't attack that last bit it's just a personal hypothesis). PS. Who ever heard of evolutionist physics or geology, I've always wondered why Creationists tend to call any opponents Evo's, i.e. if you're going to challenge every field of science at once why not be forthcoming about it. Edited by qed, : fact checking
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Brad McFall Member (Idle past 5061 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
I dont know bout the cheetin cheetahs'cheetoh either as a "pick."
The "bootleneck", "constriction," "allopatric isolation", particular path in path analysis, problems with defining effective population number, difference of Fisher, Wright OR Huxley do not necessarily have the same theorectical nor sufficient consequence unless specific geographic regions are more than implicated. Creationist criticism simply looks on all of the(se) possibilities as something "outside" their own banna(b) of an anngram. You will see something forthcoming from me over in the thread on benefical mutations and intentionality soon. I have a souce I do not have the reference title for.
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fallacycop Member (Idle past 5548 days) Posts: 692 From: Fortaleza-CE Brazil Joined: |
Faith writes: Off course it is debatable (Everything is). But the fact that most observed mutations are deleterious or neutral does not make mutations insuficient to play the driving force of evolution as long as there some small but non-vanishing set of benefical mutations.
Yes, the entire theory of evolution rests on mutation as the driving force. Is it up to its role? Well, considering that MOST observed mutations (as opposed to those simply assumed by the theory to have brought all useful traits into existence) are deleterious or useless, this is debatable.
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Equinox Member (Idle past 5170 days) Posts: 329 From: Michigan Joined: |
Jar wrote:
quote: Wow, this is an easy to understand, powerful test. Biologists can find and approximately date past bottlenecks as RickJB gave an example of. A bottleneck often reduces a population down to just a few hundred or thousand individuals. Imagine how MASSIVE a bottle neck the flood is by comparison - just 4 or 14 individuals - what a massive signal to look for. It would be obvious to any biologist that a species underwent such a bottleneck. Dating would show species after species that underwent a huge bottle neck - and they would all show the approximately the same date, even if there was some noise in the dating method. Faith wrote:
quote: You’ve got to be kidding me. It’s not like we are looking for a needle in a haystack. Biologists very often find and approximately date bottlenecks based on genetic evidence. The fact that this hasn’t been found speaks volumes. I guess it goes back to the creationists who claim that God created everything with the appearance of age - now I guess creationists must also say that god miraculously changed the genomes of every living thing on the planet after the flood to wipe out the evidence of this bottleneck. How else could we explain the glaring absence of a universal bottleneck in 2,500 BCE? Claiming that the bottleneck has been misinterpreted sounds like claiming that God created the world’s tallest mountain in Kansas, and that it’s still there, but has been “misinterpreted”. Geologists can find, (and approximately date) mountains. I haven't heard any good creationist reason for the missing bottleneck.
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Equinox Member (Idle past 5170 days) Posts: 329 From: Michigan Joined: |
philip wrote:
quote: Um, we came up with over a dozen on a recent thread. Are we going to go over them all again?
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AdminJar Inactive Member |
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Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
You’ve got to be kidding me. It’s not like we are looking for a needle in a haystack. Biologists very often find and approximately date bottlenecks based on genetic evidence. Please specify exactly what this genetic evidence looks like if it's so obvious. We know about the cheetah's severe bottleneck by the fact that it has an extreme scarcity of alleles for a great number of genes, but this is unusual and shows a very recent bottleneck. What would you expect to find from 4500 years ago? I think evidence for the Flood bottleneck is probably in the junk DNA. Edited by Faith, : No reason given. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
You might as well say its behind the sofa Faith.
How could there possibly be evidence in the 'junk DNA' which would somehow contradict the patterns of diversity we do see in various genetic populations in favour of your bottleneck from 4500 years ago. You could maybe try and argue that 4500 years is enough time to obscure the bottleneck but I don't see how you can possibly argue that the evidence is hiding in some magical form in the 'junk DNA'. TTFN, WK
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
Unfortuantely, macro-ToE theories DO require *unusual yet chaotic* chomosomal mishaps (not a few) This shows a highly faulty grasp of what the ToE 'requires'. At most it requires, in order to fit the diversity of life we see today, occasional duplications at the gene and higher levels up to that of the entire genome. These need not be 'chaotic' although they are likely to be random. The evidence for such duplications is hard to ignore look at the [i]Xenopus [i] family of frogs. Xenopus have genetic complements ranging from diploid (2n) to dodecaploid (12n). Are all of these frogs from different 'kinds' if not then kinds can clearly accomodate very large scale duplications of chromosomes or even entire genomes. Such duplications, of genes and genoes, provide a wealth of material for diversification of gene families otherwise constrained by selection and the families of genes we find throughout the kingdoms of life reflect this. TTFN, WK
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Faith  Suspended Member (Idle past 1472 days) Posts: 35298 From: Nevada, USA Joined: |
I understand junk DNA or pseudogenes to be nonfunctioning DNA that previously had a function. Dead DNA. So much defunct DNA in the genome may suggest to an evolutionist previous incarnations as other creatures, but to a creationist it suggests a lot of death of human beings over the millennia, and the death of a lot of genetic material too, by killing off all the viable alleles for those no-longer- functioning genes. I don't know how the genetics of it works exactly but that's the ballpark idea.
But let me ask YOU what you expect to see genetically that would demonstrate an earlier bottleneck? It's been asserted here that it is easily recognizable in the DNA. Is it? And what does it look like? How would a bottleneck be "obscured" over time, as you suggest? This does imply that you expect it to be something specific when it's fresh. Added by edit: You asked: How could there possibly be evidence in the 'junk DNA' which would somehow contradict the patterns of diversity we do see in various genetic populations in favour of your bottleneck from 4500 years ago. OK, so you wouldn't expect to see "patterns of diversity" if there had been such a bottleneck? Well, my answer to that is there is still a lot of diversity in the functioning DNA. The cheetah is merely an extreme caused by a much more recent bottleneck, which is why it is down to one allele per locus. But there was still a lot of genetic potential in the individuals on the ark -- how is unclear, larger genome is postulated. Edited by Faith, : No reason given.
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Wow, this is an easy to understand, powerful test. Biologists can find and approximately date past bottlenecks as RickJB gave an example of. A bottleneck often reduces a population down to just a few hundred or thousand individuals. We could start by listing all the species that we know had bottlenecks and then see how the data cluster for those species. For instance there is evidence of a human bottleneck ~100,000 years ago:
BBC - Human Bottleneck Evidence (click) Clues from genetics, archaeology and geology suggest our ancestors were nearly wiped out by one or more environmental catastrophes in the Late Pleistocene period. At one point, the numbers of modern humans living in the world may have dwindled to as few as 10,000 people. "Our data suggests there was a bottleneck that was not that recent," says Goldstein. The genetic data puts the likely date for this event at just before 100,000 years ago. And then fromThe population bottleneck, supervolcanoes and the coming end of the world - Everything2.com For example, Lynn Jorde and Henry Harpending 2 from the University of Utah have studied the patterns of mitochondrial DNA (mtDNA) within the human population and have concluded that it is consistent with a dramatic reduction in population size at some point in our past, which they calculate occurred roughly 70-80,000 years ago when the human population was reduced to as few as 5 or 10,000 individuals. ... it is believed that the last supervolcano to erupt was at Toba in Sumatra, the biggest volcanic eruption the world had ever seen, 10,000 times the size of the 1980 Mount St. Helens eruption, blowing a big 100 kilometres by 60 kilometres hole in the earth that is now known as Lake Toba. And when did this happen? 74,000 years ago, right within the 70 to 80,000 year time frame that messrs Jorde and Harpending believe that the human population bottleneck occured. Also seeToba catastrophe theory - Wikipedia Anyone know when the cheetah bottleneck occurred? Enjoy. we are limited in our ability to understand by our ability to understand RebelAAmericanOZen[Deist
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jar Member (Idle past 422 days) Posts: 34026 From: Texas!! Joined: |
The important thing is we don't see the same bottleneck across ALL species at the same time. If there had been a Flood as described in the Bible there would be this monstrous flashing neon sign in the genetic record that would be the first thing ever geneticist in the world saw. It would be out there standing like a giant among the signatures waving at all that pass, "Notice ME!"
Aslan is not a Tame Lion
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
I understand junk DNA or pseudogenes to be nonfunctioning DNA that previously had a function. Dead DNA. So much defunct DNA in the genome may suggest to an evolutionist previous incarnations as other creatures, but to a creationist it suggests a lot of death of human beings over the millennia, and the death of a lot of genetic material too, by killing off all the viable alleles for those no-longer- functioning genes. I don't know how the genetics of it works exactly but that's the ballpark idea. How can current human genetics suggest to you 'a lot of death of human beings over the millennia', except in as much as it suggests that people are human and we know that humans die? Rather than not knowing how the genetics work 'exactly' you don't seem to know how they work at all.
OK, so you wouldn't expect to see "patterns of diversity" if there had been such a bottleneck? I think my punctuation may have confused you, my point was that the diversity we do see contradicts the idea of such a recent bottleneck. So your 'answer' is just agreeing with me that there is diversity which under your schema should not be there. For a review of some theories on ancient human bottlenecks there is an interesting review by Hawks et al. (2000). This covers a range of genetic markers used to measure genetic diversity and estimate historical population sizes. The most conservative estimate covered is for a population of 175,000. Some theories, not in that paper, go as far as estimating a population of as few as 1,000 - 10,000 individuals as the result of some global catastrophe, but even estimates for that date are at around 70,000 years ago. As far as I can tell the genetics for this dating is mostly from X chromosmome and mitochondrial data and the coclusions drawn are somewhat iffy. TTFN, WK
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