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Author | Topic: Why is evolution so controversial? | |||||||||||||||||||||||||||||||||||||||||||
sfs Member (Idle past 2563 days) Posts: 464 From: Cambridge, MA USA Joined: |
quote:Crossing over reduces LD while new mutation increases it. The two are more or less in equilibrium, with fluctuations resulting from changes in population size and admixture. Admixture increases LD, after which it declines again. This can be seen nicely in that recently sequenced 45,000 year old genome. It showed similar levels of Neandertal DNA as modern humans, but the Neandertal contribution was in much larger chunks back then, since it hadn't been broken down as much by recombination.
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zaius137 Member (Idle past 3439 days) Posts: 407 Joined: |
quote: The findings are correct by Hawks and there is an apparent acceleration in recent evolution of humans, about 100 times faster than in the past. Your claim that the paper was mistaken in its conclusion based on method. Here is a citation about recent selective sweeps not being relavent in recent human history (~250,000 years).
These findings indicate that classic sweeps were not a dominant mode of human adaptation over the past ~250,000 years. Just a moment... If this is true, the argument that you make about the methodology might be false. Your opinion although informed seems wrong.
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New Cat's Eye Inactive Member |
The findings are correct by Hawks and there is an apparent acceleration in recent evolution of humans, about 100 times faster than in the past. Our population has exploded in the recent past. Here's that plot again:
With so many more people, there's that much more mutation going on, and that makes it look like evolution is happening faster - from a genomic perspective.
Your claim that the paper was mistaken in its conclusion based on method. Here is a citation about recent selective sweeps not being relavent in recent human history (~250,000 years). Selective sweeps are going to be more prominent in a smaller population. So since our population has increased so rapidly recently, then it makes sense that selective sweeps are going to become negligible.
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Dr Adequate Member (Idle past 314 days) Posts: 16113 Joined: |
The findings are correct by Hawks and there is an apparent acceleration in recent evolution of humans, about 100 times faster than in the past. He's only talking about positive selection; this is worthless with regard to the merely quantitative calculations you've been embarrassing yourself with.
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zaius137 Member (Idle past 3439 days) Posts: 407 Joined: |
quote: Also I might add that admixture may not affect LD significantly when very similar genetic populations remix.
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sfs Member (Idle past 2563 days) Posts: 464 From: Cambridge, MA USA Joined: |
quote:Yes, that is my claim. quote:Sorry, but this makes no sense. Hawks's claim is that positive selection, detected via selective sweeps, has become very frequent in recent human history. Hernadez et al claim that there have been very few classic selective sweeps in recent human history. While the second paper doesn't flat-out contradict the first, it certainly argues in the nearly opposite direction. By introducing the 2nd paper, you're supporting my opinion, not undermining it. (Nevertheless, there are serious problems with the conclusion Hernandez et al draw as well. First, the limits the set actually allow for lots of selective sweeps, especially at regulatory sites, which dominate positive selection. Second, they set no limit on partial sweeps and much selection on standing variation, which would not leave the signature they're looking for. Third, their test actually seems to be highly biased against finding evidence for selective sweeps, as noted in this psper: Genome-wide signals of positive selection in human evolution .) In any case, all of these papers require human genetic history to be vastly longer than 6000 years, so why are you introducing them?
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Phat Member Posts: 18350 From: Denver,Colorado USA Joined: Member Rating: 1.0 |
This was on the internet news today.....
Pope Francis declares evolution and Big Bang theory are right and God isn't 'a magician with a magic wand' I like that guy! I honestly don't think that there was a literal creation as many claim happened in Genesis. I know Faith will think im being blinded by satan, but im just being honest. Who knows? Maybe Ken Ham and them are right, but if so it would lead to the question of why God would trick mainstream science.Saying, "I don't know," is the same as saying, "Maybe."~ZombieRingo If You Don't Stand For Something You Will Fall For Anything~Malcolm X |
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
I still have no idea what argument he thinks he's making about linkage disequilibrium, but whatever it is, it's wrong. There's nothing about human LD that is at all suggestive of a recent origin for humans. It appears he is misreading John Hawks's papers and misunderstanding what they say. Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
... Thanks for getting back to the conversation, i thought you dropped out from boredom. No, I'm in the middle of renovating an old house (1785 ish) and just uncovered some structural damage. Working to fix that is rather exhausting.
... I think that slowing down to address other details at the moment might help. ... Good idea. You might want to start with an outline of your argument and your major points with references to substantiate the basic claims. btw - I do usually read all posts in a thread I am interested, and what I limit is the number of threads I participate in. Enjoy Edited by RAZD, : ..by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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zaius137 Member (Idle past 3439 days) Posts: 407 Joined: |
quote: You claim there is a problem in methodology in detecting selective sweeps earlier than 20,000 years, but here is the data set in graphic form:
Sorry for the bad detail look at it here: http://www.johnhawks.net/...celeration/accel_story_2007.html This is from Hawks web site it looks to me like there is no discordance in data, look at ten thousand years (first point is 20,000 years), the trend is already started to decline. The downward trend does look like it continuos uniformly threw and past 20,000 years. You continually move the goal posts, maybe you can claim that 10,000 years has got problems for detection now. If there was a problem of method you would expect an anomaly around 20,000 years (there is none). You are entitled to any opinion concerning methodology you like, but it is just an opinion.
quote: No I am not you are wrong. Edited by zaius137, : No reason given. Edited by Admin, : Provide a white background for the image.
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sfs Member (Idle past 2563 days) Posts: 464 From: Cambridge, MA USA Joined:
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quote:First, that plot is of when the "selection" is supposed to have started, not when it contributed to the genetic signature -- selection goes on for a fairly long time. Second, that plot (which I'd forgotten) in fact looks like an almost perfect illustration of the loss of power for older and older events. (The main problem with the paper shows up this plot: they interpret far too many sites as being under positive selection. That's connected to their misreading of the Voight et al paper (a misreading I confirmed with Ben Voight at the time, by the way). They're treating the entire high tail of the haplotype length distribution as representing selected loci, and that's almost certainly wrong.)
quote:What on earth are you talking about? I never suggested that long-haplotype tests fail abruptly after 20,000 years. They steadily lose power for older and older sweeps, and beyond roughly 20,000 years the power is low enough that you're not going to detect much. Why should there be an anomaly 20,000 years ago? quote:No, it's really not just an opinion. There are a handful of people on the planet who are real experts in this class of test, especially as applied to humans. I'm one of them.
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sfs Member (Idle past 2563 days) Posts: 464 From: Cambridge, MA USA Joined: |
quote:That's some pretty impressive logic you've deployed there.
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zaius137 Member (Idle past 3439 days) Posts: 407 Joined: |
quote: Please explain to me is supposed to have stared . In my simple reasoning, I assume you are looking for a signature in the genome dictating the start of a selection. You see, you can not know any direct information about the selection or duration, only its result. I see all requirements met by Hawks methodology. I would also like your patient explanation about selection goes on for a fairly long time in view of my previous statement (you can not know any direct information about the selection or duration).
quote: I never said that the long-haplotype tests fail abruptly after 20,000 years. I asked you to look at the trend after 10,000 years, a year even by your own definition does not come into question.
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zaius137 Member (Idle past 3439 days) Posts: 407 Joined: |
quote: We are just getting to the logic part
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zaius137 Member (Idle past 3439 days) Posts: 407 Joined: |
quote: Either that or it is telling you what Hawks is suggesting.
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