Adam, Eve and Population Genetics: A Reply to Dr. Richard Buggs (Part 1)


(George Brooks) #629

@Swamidass

I didn’t miss it. I was trying to decide what you meant by it!

What does “before 10 thousand years ago” mean ? Wouldn’t you agree that “before 10,000 years ago” means 15,000 years ago, 20,000 years ago, and older and older? Your reference to “before 10 thousand years ago” seems perfectly design to cause problems for @DennisVenema, and yet ignoring the mortal damage he does to the YEC position - - which is really all that matters.

Did you actually mean After 10,000 years ago? - - as in 6000 or 5000 years ago?

This is what I mean by your use of syntax. It is difficult to imagine a sentence with more landmines in it than your adamant assertion that there is “ZERO evidence” etc etc etc…

And so now I’m going to discuss the confused posting of another one of your unintended victims: @Lynn_Munter.


(Jay Johnson) #630

The entire phrasing strikes me as disingenuous. Claiming that a single-couple bottleneck is “consistent with the data” seems designed to confuse the issue. After 600+ posts, there is enough evidence to conclude that a single-couple bottleneck did not occur within the last 500,000 years, yet Swamidass’ conclusion is that there is ZERO evidence against a single couple. Huh?

What good is a conclusion when it says nothing? “A single couple bottleneck between 7 mya and ~500 kya is consistent with the data (not disproven by it).” The data provides ZERO evidence for a single couple in that time frame, yet the wording leaves the opposite impression. Somehow, a lack of data comes out as “consistent with the data.” A turn of phrase worthy of Doug Axe himself.

How about a straightforward answer: The evidence shows that a single-couple bottleneck did not occur within the past 500,000 years. Prior to that date, our data and methods are incapable of answering the question.


(GJDS) #631

From what I understand of the modelling, it shows that it cannot provide a result that commences with a couple. This is a valid result from modelling - other results may or may not support a bottleneck - but it is valid to point out the model may not be able to deal with a bottleneck of two.

This should be viewed as the ,limitation of the modelling technique, and is not disingenuous.


(Peaceful Science) #632

Sounds like exactly what i’ve said regarding our “ancestors as a whole”. However the same does not apply to homo sapiens specifically.


#633

What exactly is the difference between “ancestors as a whole” and homo sapiens? I would assume homo sapiens would just be a subset of AAAW.


(Lynn Munter) #634

Well, because it’s a subset, one can claim that ‘homo sapiens’ could have numbered two while ‘our ancestors’ were more numerous. The main difficulty lies in achieving some non-arbitrary definition of ‘homo sapiens.’

As far as I can tell the main benefit of extending this argument was to make YECs feel less ganged-up on? But it’s rather outlived its welcome in my un-humble opinion.

I’m still only halfway through catching up on @Swamidass’ last few posts, but I am immensely valuing the time he took to clearly set forth the status of the scientific evidence regarding interspecies variation and other matters! That is where the much more interesting stuff is.


(Jay Johnson) #635

There were no H. sapiens 500,000 years ago. Should we try again?

The evidence shows that H. sapiens has not experienced a population bottleneck to a single couple. Further, the evidence shows no single-couple bottleneck occurred among our ancestors as a whole in the last 500,000 years. Prior to that date, our data and methods are incapable of answering the question.


(Jon) #636

Yes that’s exactly right.


(George Brooks) #637

@Swamidass

What ?! I don’t even think I can expect comprehensible answers from you in your current fugue state.

@DennisVenema, could you explain what you think @Swamidass is trying to say?

How can we have zero bottleneck within the past 500,000 years (which embraces ‘ancestors as a whole’),
but not if we look at just our Homo sapien ancestors within 500,000 years?

That sounds pretty nutty…


#638

But the no bottleneck result is applied to the entire set of AAAW so it should also apply to the subset.


(Lynn Munter) #639

Not necessarily. I can make a claim that none of my bags of M&Ms contain only two candies but it does not make it true that none of them contain only two green candies.


(Phil) #640

I think it is sort of like saying that all dogs may have arisen through a two wolf bottleneck in the distant past (I know they didn’t but bear with me) but that all Chihuahuas never went through a a two Chihuahua bottleneck. I think.


(George Brooks) #641

@jpm

@Swamidass
I wish he was saying something like that. Let’s look at his last sample:

So, what does he mean “ancestors as a whole”? I can only interpret that to mean: all the hominids leading up to humans, Homo sapiens.

So, he concludes that data can answer the question regarding humans. So when I read it like this, I feel encouraged.

But then I remember that the problem is that Swamidass wants to be able to argue that science has not disproven a one-pair bottleneck back into the depths of time. So? Who cares about that?

YECs say that the bottleneck has to be within 6,000 years. So, let’s give them more slack than they want… let’s say it’s all tolerable up to 10,000 years ago.

But this is where @DennisVenema is at his strongest. We know for a fact that it didn’t happen within 10,000 years ago.


(Peaceful Science) #642

This is an example of the Ecological Fallacy, sometimes called the Fallacy of Division:

A fallacy of division occurs when one reasons logically that something true for the whole must also be true of all or some of its parts.
https://en.wikipedia.org/wiki/Fallacy_of_division

This is a false statement that relies on a logical fallacy. There is no value in advancing an illogical claim. There is no value in advancing a false claim. The evidence does not show homo sapiens never experienced a population bottleneck to a single couple.


Remember, our ancestors as a whole include both homo sapiens, but also others. So @Lynn_Munter explains it correctly…

However, this is not the primary benefit at all.

I do not expect YECs will be happy with a single couple origin of Homo sapiens 200 kya. Rather, I think some may be intrigued by a recent genealogical Adam, which is an entirely different thing.

Rather, the primary reason to retract this claim is because it is absurd to confidently make illogical claims. There no value in advancing claims that depend on such clear fallacy. Moreover, difficulty in understanding why an illogical statement is logical is an opportunity to clarify our thinking on things. For example, it’s clear that @Lynn_Munter understands what the evidence is telling us in relation to this question, and it also clear that others are confused. Purging that illogical claim, by understanding its fallacy, is an opportunity to clarify our thinking here.


(Jay Johnson) #643

I wish that just once you could state your claim without a double negative. In any case, I understand exactly where you’re coming from. Positing that H. sapiens began with a single breeding pair may seem logical to you, but it looks like just another ad hoc hypothesis to me. Good to see you back on your high horse again, though!


#644

I understand the problem of trying to say that a statistical measure of the whole set also applies to a subset. That makes sense. Using the Wikipedia example, the total or average ice cream consumption of the 2nd grade says nothing about how much ice cream a single student eats.

Let me illustrate what I hear from @Swamidass . If every 2nd grader eats a minimum of 1 pint of ice cream then any single student has eaten at least 1 pint of ice cream. Isn’t this a correct logical argument? Am I just hearing you wrong?


(Lynn Munter) #645

“The evidence shows that we H. sapiens have not experienced a bottleneck of our ancestors to a single couple in the last 500,000 years. Prior to that date, our data and methods are insufficiently conclusive.”

There, I fixed it. Can we be good now?


(Jay Johnson) #646

Haha. Yes, you’re right. It’s become tiresome. I’m done with it.


(Peaceful Science) #647

The problem is that you misunderstood the scientific claims. The genetics do not tell us that every 2nd grader eats a minimum number.

Rather, the total amount of ice cream eaten by the class is 5. However, if little billy tells you he got none, he might telling the truth.


(Lynn Munter) #648

It all goes back to this grammatical ambiguity. If I say none of my bags contain only two green M&Ms, and then I produce a bag with five red M&Ms and two green M&Ms, was my statement true or false?

@Swamidass has been saying ‘false’ because there could have been a generation of our ancestors which had only two ‘H. sapiens’ and a bunch of other hominins. He has read the sentence one way, while many other people (including, I think, you, @gbrooks9, and @Christy) correctly inferred @DennisVenema’s intended meaning from the original context. That is what we have to do with grammatical ambiguities like this. But once the statement is taken out of context and rephrased in a long discussion like this, it is very easy for mistakes to happen. I just want to make sure everyone sees clearly where everyone else is coming from here, because it takes a lot of careful reading to sort it all out at this point!