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

[Swamidass (Peaceful Science)]

FIrst, I want to emphasize the critical importance of taking the questions of the Church seriously. Few have done so, and so that is why there is high value in this conversation.

@AMWolfe

Well, since someone already did the whole “Since Eve was pulled from Adam’s rib, isn’t it a bottleneck of ONE?” argument, I’ll have fun picking at your “bottleneck of 8”… Wouldn’t it be rather a bottleneck of five genetically speaking? It’s Noah & his wife’s genes that were merely recombined in Shem, Ham & Japheth (assuming Noah was monogamous, and the text gives no evidence otherwise), plus three daughters-in-law.

Though not relevant to this conversation, which is merely about bottlenecks, and not special creation.

Keep in mind that some creationists have proposed that Adam and Eve were genetic mosaics, with different genomes in each of their sperm/eggs. If this is the case, there certainly could have been a bottleneck of two. From a 100% genetic point of view (ignoring archeology), it could have even been a recent bottleneck.

That does not solve the problem of the subsequent 5 genome bottleneck of Noah. And it would also give Adam and Eve a very different sort of biology than us. It would also leave us with an “Appearance of Evolution” problem, because God did not make it clear we did not descend from Apes. It also raises theological problems in inferring incest in the first family. However, it would fit the evidence.

To be clear, however, @RichardBuggs been very clear about several things. Also, it appears @agauger has taken a similar view.

1. He is not making the case for special creation. So the mosaic solution is off the table, but so is the restriction to one genome by jumping to Eve being a clone of Adam.
2. He is not insisting on a recent bottleneck, and has even been happy to accept a provisional conclusion that "a bottleneck must have been before 500,000 years ago if it happened.”
3. He has granted up front that a single couple bottleneck might not be most likely given the data, but he just wants to know of it is possible; e.g. has it been ruled out, even in the distant past?

This is not to defend his skepticism, but to make sure he is correctly represented. @RichardBuggs, as I read him, is asking a reasonable scientific question. I would instead point out that we are actually starting to engage the limits of science. Some of the discussion here seems to circle around trying to prove “what happened without a shadow of doubt.” This is not a reasonable hurdle for human inquiry. Moreover, there are some very subtle and interesting questions about the statistics involved here about rare outliers. However, these details cannot usually be resolved in public debate.

Instead, I emphasizes what @RichardBuggs appears to have already conceded, and what seems to be our common ground. Regardless of what happened, it really appears as if our ancestors never dip down to a single couple. Whether or not it is ultimately true, the evidence very strongly seems to show that, at least within the last 500,000 years, that our ancestors never dipped down to two.

While some have taken exception to their skepticism and questions, I must disagree. It is the essence of science to ask questions, even of settled answers. @RichardBuggs also is not a polemicist, but a practicing scientist who has earned the right to ask probing questions, even if he is ultimately wrong. I am not skeptical as is he, as I agree with that…

@DennisVenema

If you want to see your ideas get traction, it’s time for you to do some modelling. You also need to deal with the strongest evidence available, not simply pick at what you see as lesser evidence. For example, there are regions of the human genome that do have haplotypes that could fit into two people. Those are not the areas you need to deal with (!). The most variable ones are the issue.

This is the type of inquiry where verbal exchanges have do begin to have limited value. Population genetics in particular is notoriously non-intuitive. Rigorous modeling of the data is the only way forward. Which brings me to what I think is another point of common ground.

While @RichardBuggs has an interesting hypothesis, that is not enough.

1. At the moment, the only mathematical models that fit the full range of data we currently know about are those that show we arise in a population, that never dips down to 2.

2. The only way to change that is to present a new model, that shows otherwise.

3. Even if a model can be presented that fits the data, it may remain most likely that we arise in a population, not a couple. Consistency with the data is not the same as most likely.

As has been known for a long time, I am a frequent critique of ID. In this case, however, I think @agauger and others are taking the right path forward. They are not presuming divine action (directly or indirectly) and they proposing models of their own. They are doing the hard work of building them and plan to test them on data. That is a new and promising development in ID, even though this has nothing to do with recognizing design in nature.

Of course some of us have different beliefs about what the simulations will show. It is my hypothesis that they will end up confirming the consensus. If they do confirm the BioLogos position, and are honest about it, that will do great good for the Church, bringing them into an honest confession of the evidence. If they end up showing a new way forward, that has value on a purely scientific level. I commend them for it. I think the first option (confirming the BioLogos position) is much more likely. They might disagree.

Who cares. Let’s see what the data shows. Give them time.

Though I agree, in the meantime…

@DennisVenema

I’ll be honest that I see this discussion as providing ever-diminishing returns.