Richard Buggs: Adam, Eve, and Human Genetic Diversity

Conversation
,
1

Richard Buggs is Professor of Evolutionary Genomics at Queen Mary, University of London (QMUL) and a Senior Research Leader at Royal Botanic Gardens Kew.

(Recorded 24 May 2020) Has modern genetics disproven the idea of Adam and Eve? Could two individuals carry within them enough genetic variation to be the sole ancestors of today’s diverse human population? Theoretical and empirical studies of genetic bottlenecks show that large diverse populations can be descended from a single couple. Commonly-used methods of reconstructing past human population sizes would not point to a single couple bottleneck even if it were true. There are a range of historical scenarios by which a single couple could be the sole progenitors of present day human genetic diversity.

See this video from Richard Buggs that just came out. What are your thoughts?

3 Likes
2

@glipsnort, you should see this…

3

If I had pick someone to teach me population genetics, right now it would be him. His presentation was easy to understand, but still detailed. :slightly_smiling_face:

4 Likes
4

Cross-species polymorphism?

5

I think he meant trans-species. Keep in mind it was a non technical argument.

6

Great video! Very helpful for understanding the debate that occurred over the past few years on this topic. Thanks for sharing.

7

No, I meant to ask how he dealt with the issue. As you know, I rely on others to report on long videos.

8

I don’t think he addressed that issue.

9

Big problem for his scenario then, right?

10

No. Because we addressed this elsewhere. We’ve gone over this several times @John_Harshman, and come to consensus. Remember none of these scenarios specifically rule out all interbreeding.

11

But we haven’t come to consensus. I claim that the number of shared alleles (more than 4) precludes a botteneck of 2. You claim that convergence is a possible explanation, which I reject.

12

I think we both agree that:

  1. at most this would push the bottleneck to a min of 15 or 20
  2. the key experiments (with introns) has not yet been done.
  3. if we allow for interbreeding, then that minimum size would go down.
  4. Venema’s focus was not on this line of evidence.
13

If we allow for interbreeding, then we’re not talking about a bottleneck – we’re talking about a structured population.

2 Likes
14
  1. Agreed, but that kills off the sole progenitor idea.
  2. I wouldn’t say the intron experiment is necessary, just interesting.
  3. Interbreeding with what? Other H. sapiens? Then it’s not sole progenitors any more. Different species of Homo? Why would separately created species be interfertile?
  4. I don’t know why Venema should concern us rather than the evidence relevant to the scenario.

I’m presuming that Buggs is proposing a created pair, sole members of the species. Isn’t that it? Even if it’s a bottleneck of two from a previously larger population, where’s the interbreeding coming from?

1 Like
15

That’s true. It is an example where the way the term is discussed has diverged in two groups, and it has created a lot of confusion.

Except they still call it sole-progenitor. They mean something different by that term than you, @glipsnort, or BioLogos.

16

Not if Eve’s eggs have created differences though, right?

17

Then they have obfuscated the meaning of the term to the point where it means nothing. Why even bother?

18

They can call it a bucket of coleslaw. Doesn’t make it so.

2 Likes
19

This question is asked by minds just a few steps from madness. It is a “scientific” question of the same caliber as “could a superalien have built a Pret a Manger on the moon, then removed all evidence for it?”

20

Hehe. It is a question. Fransisco Ayala asked the question and published an analysis in PNAS. Was he a few steps from madness too? (for this particular reason, not others :slight_smile: ).

Well, it does. They are using the term differently, and they have a right to do so. Sole progenitor, in this discourse, includes theological meanings. Scientists do not have the right to tell theologians what they mean by terms in theology.

Why even bother? That is an important question.

  1. Initially, they had not realized that interbreeding is a massive loop hole. It took a while for them to realize this.

  2. They still want to minimize interbreeding, and this analysis is a way to determine how much interbreeding, at most, is required.

  3. It is part of what stimulated RTB to propose a new de novo model of AE (Mosaic Eve). You could argue that isn’t a single couple bottleneck either, but it is from their point of view.

  4. There is a history of people saying that their theological beliefs on sole-progenitorship were totally ruled out by particular genetic evidence (effective population size), requiring a minimum population size of 10,000. That wasn’t true, in fact it was never the consensus view.

  5. Even if trans-species variation ends up putting a minimum population size of 15, that is orders of magnitude less than 10,000.

2 Likes