Comments on Jeanson Accuses Duff Again

It’s obvious at even the most cursory examination. Jeanson writes:

[I]n chapter 6 of Replacing Darwin , I walked the reader through very detailed calculations on what the rates of speciation might be. Since mammals are familiar to most people, I focused on the numbers for these types of creatures. Applying these calculations to birds, we can predict the rate at which new species should form.

This should be our first red flag. A quick skim of this paragraph would leave the reader with the impression that Replacing Darwin predicted bird speciation rates, but closer examination reveals otherwise. He says that in Replacing Darwin he predicted speciation rates for mammals and that he is merely applying the same calculation to birds now. Any time that you are making “predictions” after the evidence you are claiming confirms your predictions, there’s a problem.

[I]n birds, about 11,000 recognized species exist. If birds formed new species at a constant rate over 4,500 years, then on average about 2.4 new species should form every year (11,000 species / 4,500 years = 2.4 species per year). […] As long as the long-term average is 2.4 new species per year, either of these ways is consistent with the YEC timescale. Both of these ways lead to predictions that we can test.

We have two more problems here. First of all, we are making predictions after the fact. If he could have predicted the Darwin hybrid speciation “rates” then why didn’t he? You can’t come along after a discovery and rework your math and say “See, this is what we would have predicted if we had known to predict it!”

Second, and more fundamental…where is he getting this 11,000 number from? Does he believe there was only one “bird kind” pair on board the Ark? IIRC, AiG claims something like 40 different bird “kinds” representing all extant species, so we would be starting not at 1 but at 40. What about the thousands of fossil bird genera? Why is his calculation linear? If he is advancing created heterozygosity, where a population splits into two, then he would need to say that 40 kinds became 80 sub-kinds which became 160 sub-sub-kinds and so forth, exponentially. He doesn’t say that, of course, because that would imply that we would be seeing the fastest speciation rates now of any time at history.

His only purpose in choosing to use these numbers is to come up with a post hoc prediction which appears to be close to the numbers he will later fudge from the actual science research.

And that’s not even dealing with the bigger problem, that hybridization speciation (if that’s in fact what happened with these finches) is a different type of speciation event than the created-heterozygosity-speciation he proposes. You can’t have hybridization speciation unless you already have two separate species to hybridize.


You have to remember, YEC’s redefine evolution as an increase in information.

…and I have already pointed out to you in response that a hybridization speciation would be expected to be abrupt compared with other paths. Jeanson is suggesting lions and bob cats came from a single breeding pair. Tell me, what species did these proto cats hybrid with to generate all the cat species today? Oh, that is right, none. So how does this support Jeanson’s model? That is right - it doesn’t. He has just seized on a mainstream report of abrupt species development and claimed support for rapid evolution like this somehow lends credence to the idea that some weird looking ancestral menagerie off the ark can account for all the species today. Not only is that rubbish, but it misrepresents or misapplies the substance of the report. So your gold standard turns out to have feet of clay.


A “strain” population? What on earth are you talking about Toni. I’m talking about evolution and what it actually is.

Speciation is the splitting and divergence of independent population lineages. It is therefore a form of change in biological populations over time (i.e. evolution).

Going from a polymorphism in a population to fixation is also evolution Toni so losing genetic diversity is hardly some deal breaker for calling something evolution. That loss of diversity within a population is a hallmark of much of evolutionary change from natural selection to drift so saying it’s not evolution because the result is “fewer different alleles” is just completely out of touch with what evolution actually is.


I remember. Frankly I don’t care how they define it. I’m talking about what evolution actually is.

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Jeanson writes in his article - A Second Bombshell for Replacing Darwin? | Answers in Genesis

But what about heterozygosity and homozygosity levels?

“The founder . . . appeared to be a typical member of the source population of G. conirostris [the scientific term for another one of the original species of finch]. . . in terms of average genome-wide homozygosity. . . . A gradual increase in homozygosity was then observed over the next five generations, as expected from the small number of breeding pairs (one to eight), causing genetic drift.8”

In other words, the parental species was relatively heterozygous, and the new species shifted to a state of increased homozygosity—just like Replacing Darwin predicted.

Granted, this 2018 study never established whether an increase in homozygosity was the cause or the effect of the formation of the incipient species. But in terms of smoking guns, I have a hard time thinking of a better example that fits the expectations of Replacing Darwin.

If different alleles disappear from a population as a result of differentiation, then such a process certainly cannot be responsible for building humans from microbes. Please try again.

Details, please.

<<4000; more like a couple hundred year, and almost all speciation must take place within those couple hundred years, i.e. multiple speciation events in succession, because there is considerable evidence of extant species thousands of years ago. Further, hybrid speciation leaves evidence in the genome that’s easy to spot, and that evidence doesn’t fit most species.


Can you quote where he says all evolutionary change? Or are you just going to keep building and knocking down those straw dudes?

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No, you do not understand what is being stated. There is only smoke blown by Jeanson here, no gun at all.

The founding member of the population had homozygosity similar to other members of the parent species, but subsequent species became more homozygous due to inbreeding. That had nothing whatsoever to do with the formation of the hybridized species. It’s not a prediction of Jeanson’s model; it’s a prediction of basic, agreed-upon genetics (which Jeanson admittedly seems to struggle with).

Again, it is NOT a “confirmed prediction” to take a discovery and retrofit your theory to fit it. The prediction actually has to be made ahead of time.


So for instance look at my recent blog post on Jeanson. There I cite one of his many AiG Q&A videos on YouTube where he is looking at an unrooted tree based on molecular data for human populations and singling out particular nodes as the oldest. Any competent undergraduate would tell you that can not be done. Without a root a tree has no polarity and there is no reason to assign a relative age to any one node over any other but Jeanson finds three nodes attached to what he defines as relatively long branches and says they are the oldest and therefore represent the lineages associated with the three wives of Noah. I’ve never seen a more blatant case of cherry picking in my life.


There is also mutation that creates diversity. The point is speciation is evolution. Heritable change in a population by natural selection or by drift are also evolution even though they typically result in a loss of genetic diversity. Let’s not engage in the Gish Gallop shall we. These are examples of evolution.

When two species are diverging from one another each is both loosing genetic diversity through drift and selection and gaining genetic diversity through mutation but they are losing different alleles relative to one another so even without mutation they are diverging from one another. Ancestral polymorphisms are undergoing lineage sorting in the two diverging species.

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The reason of course Jeanson chooses to not root his trees because doing so would be a tacit acknowledgment of evolution. He’s contractually obligated not to root a human molecular tree with anything not human. This all but guarantees he is going to run into problems but he doesn’t know enough to understand the mess he’s created for himself and he’s certain his audience won’t know the difference. If you go around making claims about the age of nodes on an unrooted molecular tree then you really validate someone in not taking anything you have to say on this subject seriously.

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Ah, yes. I recall that one now. He could of course have tried midpoint rooting or something similar, but I don’t think he did anything.

He could try rooting it with neandertals or denisovans, depending on what he thinks they are.

Yeah, I suspect however those options wouldn’t serve his agenda and his audience doesn’t know the difference anyway so why do it.

I talked to a former colleague on the phone last night about this a bit and I explained to him how Jeanson chose to interpret and unrooted tree and he literally laughed out loud. That’s the level of blunder we are dealing with here.

Note that the “three lineage” plan only works if the root is exactly at the node from which they all branch. If the root moves even slightly in any direction, the triple lineage disappears.

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You beat me to what I just said John.

The point I make about his insistence we pour over his every utterance is that if we can in one brief instance realize either he doesn’t understand one of the most basic concepts in molecular systematics and population genetics, how to interpret a tree, then what reason do we have to view anything he says subsequently as reliable. He either doesn’t know how to read a tree or is deliberately misrepresenting these trees to suit his conclusions and hoping no one will notice. Either way doesn’t earn him much credibility.

Neanderthals and denisovans don’t fit his Babel narrative – under their model, both were descendants of either Japheth or Ham. Also he has to posit an extraordinarily high mutation rate for them in order to fit their mtDNA into his short-timespan model. He posits that those populations “simply had different mutation rates” despite simultaneously claiming that variation in mutation rates is impossible and a sure sign that “evolutionists” are floundering by suggesting them.

I’m always inclined to give the benefit of the doubt. When I first saw the unrooted tree I just assumed it was evidence of three progenitors too.