This is a debate I moderated and hosted on my Youtube channel Standing For Truth. The debate was on the topic of Genetic Entropy. This was a great debate for anybody who has not seen it. Paul Price from CMI I believe did a phenomenal job defending Dr. John Sanford’s Genetic Entropy thesis. Dr. Ron Garret has written an extensive review of Genetic Entropy which made certain this would be an exciting debate.
We know @PDPrice well, and Genetic Entropy better. Do you know why most biologists are not convinced by his argument?
What’s to debate? The whole Genetic Entropy argument is based on the silly idea all creatures were created with “perfect” genomes only 6000 years ago and have been degrading ever since. Since we have sequenced genomes from various species going back 700,000 years ago (not to mention fossil evidence for life over 3.8 billion years) the GE concept is a non-starter in actual science.
Price basically concedes the entire debate by citing literature using the differential reproduction definition of fitness (and literature that attempts to score the distribution of fitness effects of mutations use that definition), and then changing the subject to this unquantifiable idea of “absolute fitness” that has nothing to do with reproductive success and only exists in the form of some verbal concept of “deterioration of the genome”(explained by an analogy to rust), when literature shows that reproductive fitness can continually increase despite there being a higher fraction of mutations which are deleterious than beneficial.
Another problem is this totally ridiculous idea of “the primary axiom” which Price and other creationists seem to take to mean that evolution should only ever (and under no circumstances NOT) produce sustained gains in both reproductive fitness, and their own ill-defined concept of “genetic integrity”/“integrity of information in the genome”/“absolute fitness”/etc. etc.
They will make a subtle move with these different ideas every time. They will first explain that this simplistic idea of “the primary axiom” is something like “man evolved from bacteria by mutation and natural selection”, and then they will derive from this “primary axiom”’(in a way they NEVER explain) the idea that in order for this to occur, evolution should always and only ever, under all circumstances and without any exception whatsoever, produce ever higher fitness, ever more genes, ever more genetic information, ever more “genetic integrity”, or numerous other similar ideas.
They do this so that, if and when there is NOT a net increase in whatever of these ill-defined measures occurring, they will claim this now falsifies the “primary axiom”.
Basically the idea is that, in so far as some experiment produces a result where one of these measures does not continuously increase(say there are deletions occurring, resulting in a net loss of genes), even if reproductive fitness does increase(like it does in the LTEE), then “the primary axiom”(that man evolved from bacteria by mutation and natural selection) itself must be false, because look, even though reproductive fitness increases, there are deletions occurring.
Obviously it also does not follow from the idea that man evolved from bacteria by mutation and natural selection, that evolution should only ever, and always without exception under any particular circumstance, produce a net increase in the number of genes, and/or higher rates of efficiency of enzymes, and/or more “absolute fitness”, or whatever other similar notions they jump around between. That just isn’t a requirement of the theory.
Quantitative developments like this are possible:
It goes up more than it goes down. And it goes down a lot.
The evolutionary history of life, from the first cell, all the way to Homo sapiens, is not understood by any extant evolutionary biologist to have involved one long, steady, unobstructed gain in the number of genes, without there ever having occurred any period of gene loss. It is also not understood to have constituted one long and unobstructed gain in reproductive fitness (relative or absolute), or Price’s very ill-named “absolute fitness” that has nothing to do with actual reproductive fitness as used by evolutionary biologists.
Every time Price stops talking about reproductive fitness and starts talking instead about this ill-defined and unquantified concept of “absolute fitness” by which he means something about “integrity of information in the genome” and “overall organismal function” that (under many circumstances) doesn’t affect reproductive success, you can now toss away ALL the references that mention the distribution of fitness effects of mutations and the power of natural selection, because they’re irrelevant to what he is talking about and cannot serve as evidence for Sanford’s GE hypothesis.
The whole thing is smoke and mirrors.
The somewhat apocryphal story of the miraculous flight of the bumble bee can serve as a good lesson here. As the story goes, engineers built a computer model of bumble bee flight and according to the model the bumble bee should not be able to fly. So is bumble bee flight a supernatural miracle, or is their model wrong? Obviously, when a model contradicts reality it is the model that is wrong, not reality. Genetic Entropy (GE) is the bumble bee flight model. We have mountains of evidence demonstrating that GE doesn’t happen. Even within the time frame of young Earth creationism we should still be seeing the extinction of species with short generation times, and that isn’t happening.
However, it may still be worth taking GE at face value and working through it. Without digging too far into GE, there seems to be some major problems with the assumptions in the basic model.
- Slightly deleterious mutations that selection can’t see will add up to big losses in fitness.
- The loss in fitness for each additional slightly deleterious mutation is linear.
- The rate of slightly beneficial mutations is zero.
- The rate of deletion mutations and reverse mutations is lower than the rate of slightly deleterious mutations.
Afaik this isn’t an actual assumption in Sanford’s GE. Rather that the frequency of highly beneficial mutations is so low to be of no practical consequence. IIRC Sanford considers a 10% increase in reproductive fitness to be so rare as to not be worthy of consideration.
So here he overestimates the fraction of beneficial mutations that have almost invisible positive effects(that, like his estimate of slightly deleterious mutations, most of the mutations exist in a zone of “no selection”).
Another problem is he appears to select ratios of deleterious to beneficial mutations from the literature, that strongly skewers towards extremes that are more conducive to his GE idea.
For example he’s fond of citing an older publication co-authored by Lenski wherein it was estimated that the proportion of mutations that are beneficial is 10^6:1, with Sanford taking this further to imply that a considerable fraction of those one million non-beneficial mutations being either neutral or, again, deleterious but so weakly they’re in the “no selection” zone. He likes to say that he considers this one million to one ratio very good, or among the best in the literature. We don’t have to wonder why. I have not been able to find a lower one.
Seems straightforward enough to me. If they individually are so slightly deleterious they can’t be detected by selection while alone, and so their effects only become visible when they have accumulated in large numbers, it really does become difficult to see how selection can weed them out as they should be able to accumulate across the genome. By the time their cumulative effect rises to a visible level (say that it takes hundreds or even thousands of them to reach this level), Sanford imagines, they should then have littered the genome and now selection can’t get rid of them.
The way I understand criticisms of Sanford’s idea here is, at the very least, that the frequency of such slightly deleterious mutations he envisions is unrealistically high, (the proportion of deleterious mutations is actually skewed more towards a stronger deleterious effect, which are visible to selection).
So he envisions too many mutations in the “no selection” zone. He envisions mutations of strongly beneficial effect to be too rare, and he envisions the ratio of beneficial to deleterious mutations to be too extremely biased towards deleterious. There are other problems too, but generally to show the “inevitability” of his GE, he will play around with these ratios so as to produce his desired result.
If the rate of slightly beneficial mutations is equal to the rate of slightly deleterious mutations then there isn’t a problem.
That number would be beneficial enough to be seen by selection. I am talking about slightly beneficial mutations that can’t be seen by selection in the same way slightly deleterious mutations aren’t seen by selection.
What if the sum of their deleterious effects is so slight that selection still can’t see them?
I do hope that in one of these “debates” on genetic entropy, the person arguing in favor of the concept will address that fitness effects are not constant. how mutation-selection balance fails to occur, and how harmful mutations accumulate in an approximately linear fashion over time, despite changing as a fraction of possible mutations as they due so. To date, nobody has.
This is an implicit argument from authority. It doesn’t matter whether most biologists are convinced. Most professional scientists cannot afford to get blacklisted for being associated with creationism.
Sorry @PDPrice, that is not an appeal to authority. It is a test of basic knowledge. You don’t have to agree with people to be able to accurately represent what they think.
@PDPrice, as long as you are here, I have some questions for you. Are you willing to answer some of them?
Wow, can’t argue with science! Just look at that graph. Glad you added the legend.
Sure, I’ll see what I can do.
Great. Now, I need to tell you unfortunately I don’t have time to get into it tonight. So I’ll try and post tomorrow. I do look forward to your response. Peace.
You need only read Kimura’s paper for a full explanation of this. It’s referenced in the handout for your convenience.
how harmful mutations accumulate in an approximately linear fashion over time
Simple: since mutations happen at a stable rate in populations, we have a steady and constant accumulation over time, which translates to a linear function.
despite changing as a fraction of possible mutations as they due so.
“Fraction of possible mutations” is not a concept I’m familiar with, in reference to GE.
By playing the “most biologists” card … well, no matter. Why do you think most biologists aren’t convinced? Given our current academic climate where one can easily lose tenure, or a job, or whatever for even appearing to support creationism in any form, I am afraid I just can’t put stock in this kind of objection. Here’s a quote that people, thinking they’re clever, often direct toward me:
“It is difficult to get a man to understand something, when his salary depends upon his not understanding it!”
The irony they fail to grasp is just how much this cuts more deeply the other way…
Until Joshua comes back tomorrow, maybe you could spare a moment to consider a simple question:
How come the giant reptiles, including the large marine reptiles, all drowned during the flood, leaving their bones BELOW the notorious K-T boundary layer …
… while at the same time, mammalian whales drowned much later, leaving their bones above the K-T boundary layer, along with other large mammals like cows, bears, giraffes, gazelles, sloths and so forth?
Why wouldn’t dinosaurs like the Brontosaurus easily avoid drowning LONGER than horses, cows and elephants? Even modern flightless birds (like ostriches) don’t drown with the bulk of the dinosaur forms… as well as penguins.
Standard Creation excuse: We YECs can’t publish any evidence supporting our YEC claims because we’d be EXPELLED!! Don’t you guys ever get tired of whining about what persecuted victims you are?
How is it we have sequenced the complete DNA of many extinct species (mammoths, woolly rhinos, dire wolves, etc) going back to 700,000 years ago and NOT ONE shows any evidence of “genetic entropy” between them and their extant species descendants?
You’re 100% accurate. It really is an appeal to authority. This is a very common fallacy coming from the critics of young earth creation.
Sure you agree that most biologists disagree with YEC, including Genetic Entropy. I asked you if you know why we disagree. Now, perhaps we are wrong. A rational conversation isn’t possible, however, until you understand why we reject Genetic Entropy.
Rather than giving even an attempt at answer, you’ve claimed this is an appeal to authority. I didn’t ask you to agree with us, nor did I claim we were correct. Rather I stated what you already know, and asked you to explain why.
This seems to be a transparent admission that you do not know why we disagree with Genetic Entropy.