Ahh yes, thew Lord of Delusion makes an appearance....
quote:
Originally posted by Fred Williams:
quote:
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YOU SAY:
No, if there were an intergenic locus of 5kb that showed no change between species in 20 million years, I would be a bit suspicious. But nothing in 300+ bps? Chance alone can probably explain that...
I SAY:
Chance alone? Calculate a bit on it, please. Demonstrate the odds.
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SLP: Mutation rate estimates are along the lines of 1 mutation per 10^9 bps per generation. At a 20 year generation time, that amounts to 1 million mutations in 20 million years. So any given site in a 3.2 billion bp genome has about a 0.03125% chance of 'suffering' a mutation in that time frame. That works out to less than 1 in 300 bases.
Very rough estimate and calculation, but it demonstrates my point.
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ROTFL! Very ROUGH indeed! This is bogus beyond words. First, it’s 1 million generations, not mutations.
The stupidity and eagerness of the creationist to 'prove their mettle' is beyond words.
The young earth creationist electrician apparently overlooked this:
"
Very rough estimate and calculation, but it demonstrates my point. "
Very rough - I made a simple math error.
In a genome of ~3 billion bp, an error rate of 1 per billion per generation works out to 3 million mutations in 20 million years, not 1 million.
Williams the young earth creationist - who believes that 8000 Kinds on the ark hyperevolved to produce the extant diversity of today via magical evidence-free 'non-random mutations' - laughs at many things. I laugh at someone that actually thinks that the bible is literally true - indeed, I am still waiting for the evidence that leprosy can be ured by killing a couple of pigeons over running water and binding their wings with red thread...
quote:
Second, the rate you cite is way too low; your source must be either deleterious only, or rate/year, not generation. Estimates I’ve seen for *all* mutations (harmful through neutral through beneficial) runs at roughly 100 per diploid/generation, or 3 x 10^-8 bps/generation.
My source explains that the estimates are generalzed estimates that have been seen to be applicable to populations of mice as well as fruit flies (for example).
They go on to break it down to one mutation per gene in the germ line every 200,000 years.
Using that extrapolation, it works out to about 100 changes in 20 million years in the average gene.
The ZFX/ZFY
genes are well over 1000 bp in length, not including introns. We can say that therefore, being generous, that about 1 in 10 bps should have 'changed' in 20 million years in this gene.
Of course, 1 in 10 is an average - it does not mean that, literally, every tenth site should have suffered a mutation.
But more importantly - and this is something that I should have picked up on before, Borger's original claim is bogus anyway.
It is the Ks value ("In contrast, the Ks value between human and hominoid primates for the ZFX gene was 0.008 for each comparison") - Ks being synonymous substitutions - that is the same, NOT the exact nucleotide sequence!
The species exhibiting identical nucleotide sequences for a partial exon in ZFX (~400 bp) did not infact diverge 20 million years ago. 18 million is a better value. In addition, looking at the last intron of both the ZFX and ZFY genes rveals a healthy amount of difference - 35/1229 between human and orang in ZFX, for example.
Tells me that the coding regions are under selective constraints.
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And of course your sources are always right about everything. Like ReMine, for example. ReMine the creationist magician and engineer says that Haldane's model is beyond reproach and that 1667 fixed beneficial mutations is too many to account for human evolution so it MUST be true.
My source is "Molecular Cell Biology, 3rd Ed.,p. 242-3. Alberts et al. 1994.
My source goes on to say:
"...a single gene that encodes an average sized protein (containing about 10^3 coding base pairs) would suffer a mutation once in about 10^6 cell generations."
How does that bode for Borger's insistance that a particular 300+ bp exon, that is under selective constraint, within a gene
must have accrued some mutation in that time span?
Funny how you don't address that.
11th Commandmant and all that, I suppose...
quote:
Finally, last and certainly not least, you assume a constant population size of 1 through that entire 20 million years! I didn’t realize we were asexual, and that there really was no Eve, ever. Just Adam, Adam Jr, Adam III, etc! ROTFL!
Yes, ROFTL!
Do you not assume a conststant population size when you hawk Haldane's dilemma?
Or is there some sort of double standard going on here?
Or is it some sort of scientific naievete being displayed by a creationist that is out to 'prove' his ancient religious text literally true?[/quote]
Granted this isn’t a straightforward computation. It’s an interesting problem. Here’s my rough estimate:
Let’s first try to calculate the number of organisms after 20 million years who should have a mutation at a specific neutral site. Assume 3x10^-8 bps/generation, and a population size of 1M. Also assume 20 year/generation. In 20 million years this is 1M generations. So, after 20 million years we will roughly have 3x10^-8 * 10^12 = 31,250 organisms with a mutation at a specific site. This is a rough estimate and will actually be lower because 1) duplicate hits are not accounted for, 2) it assumes the mutation is always inherited. Number 1 is negligible and can be ignored, number two however impacts the number by roughly 50% (due to mendelian genetics). So, that leaves 31,250/2 = 15,625. Out of a population of 1M, after 20 million years 1.6% have the mutation at a specific site.
Now we need to know what the odds are that 80 bps will avoid the mutation. This is given by:
P = 1 - [(100 — f)/100]^N, where f = frequency, N is number of attempts. In our example,
P = 1-[(100 — 1.6)/100]^80 = .725.
This means there is a 72.5% chance that at least one of the 80 neutral sites should have been mutated. Or, there is a 1 in 3.6 chance we would not see a mutation within the 80bp window.
For 300 sites, we get P = .992, or 99.2% chance, which means the odds are 1 in 125 we do not see a mutation within a 300bp window.
These odds obviously do not favor evolution, but they are also not near significant enough to declare the ZFX sequence anomaly a nail-in-the-coffin evidence against the theory. Still 1 in 125 chance IMO refutes your claim that chance alone can explain it. Maybe you got lucky, again. Evolution always gets lucky! LOL!
BTW, it does get really bad if the sequence were 5Kb. Better hope we don’t find one like that. The number becomes P = 9*10^-36![/quote]
Oh boy!
You are really on top of things, aren't you!
Off top class now - will comment on the rest later....
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