tag:blogger.com,1999:blog-37148773.post4523351225205982721..comments2024-03-27T14:50:47.345-04:00Comments on <center>Sandwalk</center>: The Hardy-Weinberg EquilibriumLarry Moranhttp://www.blogger.com/profile/05756598746605455848noreply@blogger.comBlogger17125tag:blogger.com,1999:blog-37148773.post-25979426815747059482013-03-29T14:49:01.890-04:002013-03-29T14:49:01.890-04:00I hate to be pessimistic, but we all know that not...I hate to be pessimistic, but we all know that not every undergraduate knows this. Even some ID proponents are or have been undergraduates.<br />Konradhttps://www.blogger.com/profile/06867375994008638278noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-64566565388446934692013-03-29T01:05:13.623-04:002013-03-29T01:05:13.623-04:00Oh. Reality. I was talking about models ...
Oh. Reality. I was talking about models ...<br />Joe Felsensteinhttps://www.blogger.com/profile/06359126552631140000noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-61513624423938528542013-03-28T18:51:49.032-04:002013-03-28T18:51:49.032-04:00Gasiorowski gets near to sorting it out for allele...Gasiorowski gets near to sorting it out for alleles. Any mutation within an allele will disturb the equilibrium, whether it impacts phenotype or not, so, as TheOtherJim explains, HW concerns genotype. But even assuming there are no changes between alleles, surely there will be ongoing non-allelic changes - genotypic changes - elsewhere in a genome, that may be relevent for macroevolution? In this respect, it may be tidy for the mathematics, but one cannot really assume that evolution does not happen.Donald Forsdykehttps://www.blogger.com/profile/18038104286639798795noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-52321227376723095752013-03-28T18:20:19.666-04:002013-03-28T18:20:19.666-04:00"Every undergraduate knows this."
And ev..."Every undergraduate knows this."<br />And even laypeople interested in biology. It's one of the things I learned in Dr. Noor's recent MOOC about evolution and genetics.Khttps://www.blogger.com/profile/12460075520187803334noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-44712877044768545502013-03-28T12:32:39.275-04:002013-03-28T12:32:39.275-04:00To be pedantic...
If we are talking about a "...To be pedantic...<br /><br />If we are talking about a "randomly mating sexual population" that produces sperm and eggs then the following is possible: <br /><br />If females all have alleles A (p = 1.0) and males all have allele a (q = 1.0) then you need two generations of random mating--not a single generation--to achieve the equilibrium. rich lawlerhttps://www.blogger.com/profile/13353965284524429553noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-81498958852355570522013-03-28T09:39:22.825-04:002013-03-28T09:39:22.825-04:00@Donald Forsdyke,
Don, your comment doesn't m...@Donald Forsdyke,<br /><br />Don, your comment doesn't make sense. Can you re-phrase it?Larry Moranhttps://www.blogger.com/profile/05756598746605455848noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-89609012937598132552013-03-28T09:36:43.340-04:002013-03-28T09:36:43.340-04:00I meant "how you would achieve that in a real...I meant "how you would achieve that in a real population", rather than in say, some fruit flies in a bottle.John Harshmanhttps://www.blogger.com/profile/06705501480675917237noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-84929747232693838842013-03-28T09:11:04.608-04:002013-03-28T09:11:04.608-04:00If one defines evolution strictly in terms of phen...<i>If one defines evolution strictly in terms of phenotype, this is perhaps correct.</i><br /><br />Is this a typo or error? HW is quite clearly just measuring allele frequencies(ie genotype). TheOtherJimhttps://www.blogger.com/profile/01727633779107067250noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-85072285856452091242013-03-28T08:00:48.842-04:002013-03-28T08:00:48.842-04:00(presumably following DNA changes)
The Hardy-Wein...<i>(presumably following DNA changes)</i><br /><br />The Hardy-Weinberg model assumes, among other things, that there are <b>no</b> mutations. Mutations, whether phenotypically visible or not, disturb the HW equilibrium of allele frequencies and they "make evolution happen" (even if only by shifting the point of equilibrium).Piotr Gąsiorowskihttps://www.blogger.com/profile/06339278493073512102noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-48689999760987275432013-03-28T07:50:16.942-04:002013-03-28T07:50:16.942-04:00On this note, Professor Moran says: "The Hard...On this note, Professor Moran says: "The Hardy-Weinberg describes the situation where evolution DOES NOT HAPPEN and thus serves as the null hypothesis for testing whether evolution is happening. Every undergraduate knows this." If one defines evolution strictly in terms of phenotype, this is perhaps correct. But DNA is constantly changing and so-called "sibling species" with no apparent phenotypic differences, HAVE CHANGED (presumably following DNA changes) to the extent that their members are reproductively isolated from each other. We should at least pause before declaring that evolution has not happened.Donald Forsdykehttps://www.blogger.com/profile/18038104286639798795noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-28824582119469020832013-03-28T01:55:36.792-04:002013-03-28T01:55:36.792-04:00John, if you take the heterozygotes and replace th...John, if you take the heterozygotes and replace them by a 50:50 mixture of the two corresponding homozygotes, you will get a change of genotype frequencies which keeps the gene frequencies the same. It even works for multiple alleles. That is does work is obvious once you consider what that does to the number of copies of each allele -- it keeps the allele numbers the same.Joe Felsensteinhttps://www.blogger.com/profile/06359126552631140000noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-55149396872428554482013-03-27T21:47:34.163-04:002013-03-27T21:47:34.163-04:00Apparently I have led a sheltered life with regard...Apparently I have led a sheltered life with regard to "law". But "equilibrium" seems perfectly appropriate, since any frequency combination of genotypes will reach HW frequencies in a single generation, given the HW conditions. OK, the least little change in allele frequencies will destroy the supposed equilibrium, but at least it's robust to changes in genotype frequencies that don't effect allele frequencies. (How you would achieve that is unclear; but usually it's just the initial condition out of whack.) That should count for something.John Harshmanhttps://www.blogger.com/profile/06705501480675917237noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-73386598833361151792013-03-27T20:07:52.474-04:002013-03-27T20:07:52.474-04:00When I first read the post, I misunderstood and th...When I first read the post, I misunderstood and thought Larry was quoting one of the comments from UD, which would be unfair. So I was surprised to click thru and find that this was actually a feature article from the site. I don't know why I should be surprised, but for some reason I keep underestimating the depths of stupidity to which these people will sink.<br /><br />The response to Joe's article is particularly interesting, in that they (predictably) say "Yeah, but that's just microevolution", without realizing (or at least without admitting) that this is already enough to refute niwrad's entire thesis.<br /><br />IDiots, the lot of them.Faizal Alihttps://www.blogger.com/profile/00937075798809265805noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-31123830851448736992013-03-27T19:25:49.280-04:002013-03-27T19:25:49.280-04:00The phrase "Hardy-Weinberg law" gets 36,...The phrase "Hardy-Weinberg law" gets 36,100 hits on Google and that includes the title of a Britannica Online encyclopedia entry. It is unfortunate,but common. In my book I call them Hardy-Weinberg Proportions. The fact that altering the genotype frequencies in such a way that the gene frequency isn't altered does not change the future composition of the population is mildly interesting, but the phrase "Hardy-Weinberg Equilibrium" for that is misleading. Almost any alteration of genotype frequencies you do will not leave the gene frequency unchanged.Joe Felsensteinhttps://www.blogger.com/profile/06359126552631140000noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-50565446990355210762013-03-27T19:25:05.286-04:002013-03-27T19:25:05.286-04:00They confuse a neutral equilibrium with a stable o...They confuse a neutral equilibrium with a stable one. Little wonder, if Niwrad the Toidi thinks a trivial binomial expansion of (p + q)² is some sort of advanced maths. He can't have seen the inside of any handbook of population genetics, or he wouldn't be asking dumb questions like "How many equations are there in evolutionary theory?"Piotr Gąsiorowskihttps://www.blogger.com/profile/06339278493073512102noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-68617293083642458512013-03-27T18:45:58.122-04:002013-03-27T18:45:58.122-04:00I should be surprised no longer by their stupidity...I should be surprised no longer by their stupidity.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-54116781445197839782013-03-27T18:45:43.717-04:002013-03-27T18:45:43.717-04:00I don't recall ever seeing Hardy-Weinberg call...I don't recall ever seeing Hardy-Weinberg called a law. And I've never seen it used as some kind of enforced straight-jacket that prevents evolution. Oddly enough, it would prevent microevolution, which most IDiots claim really happens, rather than macroevolution, which they claim doesn't. <br /><br />I've seen that phenomenon -- of IDiots reflexively rejecting microevolution -- many times, though, as in claims that the <i>Biston betularia</i> example is faked, fitness is tautological, and so on.John Harshmanhttps://www.blogger.com/profile/06705501480675917237noreply@blogger.com