If we assume constant mutation rate there is no possible rooting, because there’s no way to make every branch come out exactly even at the tips. Of course even with a constant average rate there would be some variance in realized number of substitutions. But this means that even an assumption of constant rate must give us error bars around the location of the root, and likely enough in this case to make its location ambiguous.
The greater point is that Jeanson doesn’t attempt to root the tree at all, even by midpoint rooting. He just assumes an unjustified root.
If the only thing that ever happened was gene loss, sure. But I have to say that is fantastically simplistic thinking.
Surely anyone can understand that we can have a period of loss here, and a period of gain there, and that these two can fluctuate up and down such that, over sufficiently long timescale you still get a net increase in alleles?
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 just isn’t and it’s fatuous in the extreme to pretend otherwise.
You appear have a ridiculous straw-man of the process of evolution in mind, which reflects next to nothing of what evolutionary biologists think has happened in the history of life.
“ Let me provide an example of how even a very brief statement can justifiably erode confidence in someone’s scientific claims. Jeanson participated on one of his many streaming events on the Answers in Genesis You Tube channel on June 14, 2020 (start at 9 minutes 30 seconds and watch for about 4 minutes to see exactly what I’m talking about). There he showed a molecular tree showing the relationships among DNA sequences derived from various human populations (incidentally as far as I am aware Jeanson produces none of these data himself but only borrows sequences produced by others from public databases). This tree was unrooted”
OK, I looked. If there’s a midpoint root, it would seem to somewhere fairly deep inside the rightmost cluster, which doesn’t work for Jeanson. There would have to be exactly 3 clades, one for each of Noah’s daughters-in-law. There could be nothing outside those three.
Was this a published tree or did he analyze published sequences? If the former, can anyone cite the actual publication? If the latter, how did he analyze them? I’m presuming these are complete mitochondrial haplotypes. I would also presume that the rightmost cluster is a bunch of genomes from sub-Saharan Africa, which again kills Jeanson’s notion.
He’s vague about all that. The bottom line is he doesn’t understand why it’s important to root a tree if you are going to attempt to draw the sorts of conclusions he’s after. He just has absolutely no idea what he’s doing. I think people are really giving him far too much credit.
He claims that these are three lineages that even secular scientists find. There should be some references somewhere. I think this is important because he is only summarizing his point at a high level using the unrooted tree, but claiming that more rigorous studies find the same three lineages. I think it is acceptable to summarize the situation this way, even if it is on an unrooted tree, if there really is published studies that more rigorously demonstrate this.
There should, if Jeanson is relying on them, and he should have cited them. Did he?
But if these three lineages are to fit Jeanson’s scenario, the root must split the tree into exactly three. A midpoint root doesn’t do that. A root chosen explicitly so as to split the tree exactly three ways is of course a bit of circular reasoning. Though there may be three (or more) actual groups, they aren’t the ones he needs. The three groups Jeanson needs are artifacts.
Notice Jeanson explains away what by his “eyeball” method is a fourth node as an artifact because it doesn’t fit his story to accept it as anything meaningful
I do know. He doesn’t root the tree either with a midpoint or outgroup or any other method. That’s obvious. He doesn’t understand what he’s doing. He’s making up stuff as he goes along to fit his narrative.
But if you read his latest article in a vacuum, I’m the one with an invented narrative.
MacMillan weaves a wandering tall tale. He invents a narrative, and then twists our exchange in the context of this invented narrative, apparently in hopes that the narrative will make the additional dishonesty more plausible.
I’ll clarify a few things about what Jeanson does.
In the image below, I reproduced Jeanson’s unrooted mtDNA tree (A), and then rooted it on the midpoint (B).
The red arrows point to the nodes that Jeanson claims are the 3 daughters-in-law of Noah. To a lay audience, the arrows on the unrooted tree really look like they could be pointing to 3 contemporary progenitor women, but as has been discussed in this thread already, it’s impossible to interpret the tree in that way. Any root, even if not the midpoint, puts at least one of those nodes as the descendent of another node. When you do root the tree on the midpoint, none of his chosen nodes are ancestral to the African mtDNA sequences, which is why he invokes higher mutation rates in African populations to avoid this problem. I describe all of this in part 6 of my review of his book.
Here’s the “technical paper” where Jeanson describes how he generated the unrooted tree, and how he interprets it:
The original population contains alleles in large and small sizes. As a result, the population includes large, medium, and small dogs. This population has not yet adapted to the conditions.
Two new populations are diverging from the original population, and over time, one of them has only small dogs and the other large dogs due to the conditions. Now, these new populations have adapted to the conditions, as the population of large dogs lives in an area where conditions favor large forms and small dogs in an area where conditions favor small forms. New populations are specialized. There has also been a barrier to reproduction between them, as populations live geographically apart. The large size difference of dogs also prevents them from interbreed, so biologically we could talk about speciation.
Please note the following: 1) They are now more specialized than their ancestors on row. 2) This has occurred through natural selection. 3) There have been no new genes added. 4) In fact, genes have been lost from the populations — i.e. there has been a loss of genetic information, the opposite of what microbe-to-man evolution needs in order to be credible. 5) Now the populations is less able to adapt to future environmental changes compared to the original population, which contained alleles in both new populations.
You said that speciation is always evolution. But how such a process that removes alleles could be responsible for the fact that we have been built from microbes over very long time?
