I’ve been out of town on business for a few days, but it appears I may have a bit more spare time now. Recapping – Concerning the question of genetic load. 6days believes that humans are distinctly deteriorating genetically, due to mildly deleterious mutations in our DNA (sometimes called VSDMs – Very Slightly Deleterious Mutations) accumulating over generations. I mentioned a 1995 scientific article by Alexey Kondrashov (a Professor at Cornell) in which he presents some mathematics showing that there are ways in which genomes can compensate for this “genetic load” problem.
In my previous post to 6 days on this subject, I said:
That’s it? That’s what you meant when you said you were “using his calculations"? You gotta be joking.
You are responding to a paper that presents and relies on over a dozen equations, including partial differential equations, which requires specifying the coefficient of selection (s), effective population sizes (Ne), forward mutation rate (u), reverse mutation rate (v), and the number of nucleotides (G). It shows how to use this data to compute the deleterious mutation rate (U), time-interval probability functions … <at this point we are less than 50% of the way through Kondrahov’s paper>. For Professor 6days, this can all be summarized as just “100 new mutations”….
The opening line in his response was:
Yes..... essentially correct.
I had not expected 6days to directly affirm that indeed he understood almost nothing in Kondrashov’s paper. The very reason Kondrashov spent the time to research and write the paper was specifically to address the issue of accumulating new mutations, and that’s what he based the title of his paper on. 6days and I have traded several posts dealing with Kondrashov’s paper, but 6days’ response shows that his understanding stops right where Kondrashov starts when authoring his paper.
In a prior post 6days says:
…<regarding the rate at which mutations accumulate> Kondrashov specified 100. That was a very low estimate. Nachman and Crowell said the number was 175.
So? Show me in Kondrashov’s paper where he specifies a mutation rate above which extinction is inevitable. All I see are the mathematical relationships relating mutation rates to population sizes, the number of nucleotides, selection coefficients, and so on. I previously pointedly invited you to follow the math Kondrashov uses, and show where it fails. But so far you seem to be dead stuck at the title, and scared to follow specific numbers into the paper itself. The following enlightening comment from you shows your feelings on actually understanding the technical arguments Kondrashov presents:
You are wanting to get into the weeds with his hypothesizing
What you want to dismiss as “wanting to get into the weeds” is called “doing science”. You have shown you prefer to mindlessly accept oral traditions from iron-age nomads as the most reliable science, but real scientists today very often depend on carefully defining the relevant parameters and presenting the supporting mathematics for critical review. You might find it liberating, try it.
Looking over all you have said about Kondrashov’s paper, I see nothing but generic allusions to its content and approach. The lack of specificity leads me to suspect you don’t actually have a copy of his paper at hand. Disabuse me of my suspicions by, say, turning to his list of “REFERENCES” at the end of his paper, and in his third listed reference tell us who the first listed author is and what Journal that author’s referenced paper can actually be found in.
...rather than discuss the data.
Oh I do want to discuss the data … and to examine the genetic mechanisms that can affect the data. You are the one who thinks the data is nothing more than just declaring there are lots of mutations occurring.
(Kondrashov calls it possible resolutions). His math and graphs are an attempt to rationalize data (mutation rate) with his beliefs in common ancestry.
His math and graphs are showing that genetic load is not necessarily a slippery slope to extinction. Can you show anywhere in his paper that he relies in any way on common ancestry?
Now if his paper facilitates an understanding of how common ancestry can occur, so what? Elementary algebra is used in common ancestry ideas … does that indict the integrity of elementary algebra?
There may be 20 times that amount (or more) <20 times 100 mutations per generation>.
Or you may be desperate enough to feel you have to suggest values more than an order of magnitude higher than are realistic. Specifically, a recent published paper:
The Human Germline Mutation Rate Numerous lines of evidence, many based on whole-genome sequencing of parent–offspring trios, show that the average human mutation rate is in the range of 1.1–1.7 x 10^-8 per nucleotide site per generation for base-substitution mutations alone (Lynch 2009; Campbell et al. 2012; Kong et al. 2012; O’Roak et al. 2012; Ségurel et al.2014; Besenbacher et al 2015). … an average newborn contains ~100 de novo mutations.
From “Mutation and Human Exceptionalism: Our Future Genetic Load”
Michael Lynch
GENETICS March 1, 2016 vol. 202 no. 3
http://www.genetics.org/content/202/3/869 |
You got something (other than wishful thinking), such as from actual recent peer–reviewed scientific literature that says this is a factor of 20 times too low?
Those estimates were based on what was considered functional DNA, which at that time was considered to be a small percentage of our DNA.
Interesting point. How about a cite, please.
Kondrashov then tries to "resolve" the problem with synergistic epistasis and truncation selection.
So? His paper simply shows, in formal mathematical detail, that there are mechanisms which can overcome genetic load. Bellyaching about a mathematically-based solution is kinda childish. If the math is wrong, show where.
The problem is much worse now than he could have imagined when he wrote that article back in 1995.
I am perfectly willing to look at relevant scientific data or studies since Kondrashov’s paper. How about posting some links to such studies? (I have identified a number of similar published studies since Kondrashov’s paper. You wanna get into the nitty-gritty on some of them?)
The evidence supports that which God tells us…
No, science does not support much of what is recorded in those ancient nomadic tribal accounts that you are emotionally wedded to.
Finally, lacking anything other than hot air on this genetic load question, you aim your sights more directly at me:
Would you care to discuss a few things you are dodging? Or, have your thoughts evolved a bit?
When my thoughts quit evolving I hope it is only because I have reached the end of my life. So far in my life the evolution of my thoughts have taken me from a strong Christian mindset to a more evidence and logic-based understanding of the world.
* You seemed to think there are individuals who have unusually low numbers of mutations.
Well, earlier you said:
… In this article <Kondrashov’s article> he refers to the stochastic load as a paradox.
Stochastic, huh? Doesn’t that mean the accumulation of VSDMs is pretty much random? That would mean they have a statistical spread, and mathematical concepts like standard deviations become applicable. How many standard deviations off the norm do you have to go to be down to a millionth of the original population?
* You seemed to think Kondrashov wasn't talking about humans.
Creationists hate reading. I already addressed this specific claim back in post 164.
*You seemed to think that mutations to non coding DNA that had regulatory function can be dismissed as insignificant.
Creationists hate reading. I have said zero – not one word or mention about whether the mutated DNA was coding or not. Nor does Kondrashov in his paper.
* You seemed to think selection can remove even the slightly deleterious mutations.
Creationists hate reading. I have made no such claim, other than referring to Kondrashov’s article dealing with exactly that, that you assiduously dodge getting into specifics on.
* You seemed to think 100 mutations added to our genome each generation was just a silly misleading number.
Creationists hate reading. Nope, you are making up false claims because you have nothing better to fall back on.
* You seemed to think science supports your beliefs?
Not “seemed” (past tense), since science does support my position on this genetic load question. I still have Kondrashov’s scientific paper that you can’t get past the title on.
(Wow, if I were goal posts you would have pushed me into the next county.)