I’m not sure how you mean that.
Its existence was predicted before it was possible to actually determine its existence because we know we share common ancestry with other great apes. That’s a pretty strong indicator that common descent is true. But it would not be possible to determine common ancestry just from the fact that one of our chromosomes has telomeric remnants along one of its arms.
You’re shifting between evidence and something being determinative. Can you answer the question about whether C2f is evidence?
Of course it is. But if Adam was created as human, he would logically have possessed the genetics of a human. You would need an extra explanation in order for him to have chimpanzee genetics. What could that explanation possibly be?
Not at all. It seems you did not understand my comment. What I was trying to convey was that, from the knowledge that we share common descent in just the last few million years with the other great apes, and also that we had one fewer chromosome pair than the others, it was known that there had to have been a fusion of two chromosomes in our genome. Then, when the technology became available to actually find the fusion site, there it was.
IOW the knowledge that common ancestry was true allowed a prediction to be made regarding what would be found when our genome was sequenced.
It is up to you to decide if this is the sort of thing you are referring to when as if C2f can be considered evidence for common ancestry. I don’t really know what you are getting at so I don’t want to answer on your behalf.
Yes. An important part of Joshua’s scenario is that Adam and Eve would have been interfertile with the other humans alive at the same time outside the Garden of Eden. That by itself does not tell us whether they would have had 48 or 46 chromosomes.
Of course. But why, if you’re specially creating a human, would you give him random atavisms? It makes no sense.
@swamidass can answer for himself, but I think he has a rather expansive concept of the term “human” in this context. I do not believe he is necessarily using it in a biological sense.
How is that in any way relevant to what we’re talking about here?
No. I hadn’t read the entire thread. No disrespect was intended.
As with most communities of old friends (and new friends and some vague acquaintances) assessing motives can get tricky. Tangents arise at times, especially when a thread passes the hundred count. That’s why we have great moderators like @Dan_Eastwood who divide/start new threads.
Sorry, I think there was a misunderstanding on my part in my last comment. In the comment before that one, I had suggested that maybe you want to say the evidence is underdetermined. I’m guessing this is why you mentioned “determine common ancestry”, but it was in a different sense than I was using “underdetermined” and so it seemed to me that you were shifting something.
What I meant by the evidence being underdetermined is simply that it doesn’t help us pick out one theory over another. So, technically, it wouldn’t be evidence but mere data.
Now you want to point out that something like C2f was predicted based on evolutionary theory, but not answer whether this makes it a piece of evidence, because you “don’t really know what [I’m] getting at” and so you “don’t want to answer on [my] behalf.”
But what I’m getting at shouldn’t make any difference to whether C2f is evidence of common descent and I’m not using “evidence” with any secret definition in mind.
So, again, either C2f is evidence of common descent or it is not. If it is, then if Adam had C2f then there would be evidence that Adam had ancestors of common descent. If you want to deny that Adam having C2f is evidence of his common ancestry with other humans then what you actually want to say is that C2f is undetermined as evidence of common descent.
And to try to clarify again how this relates to the broader topic, when the idea of this C2f issue first came to me it was as an illustration of how @swamidass’s de novo hypothesis still retains some omphalism-esque elements, like some YEC scenarios. So far everyone in the thread has claimed that if we are aware of some evidence against a claim then believing the claim becomes irrational. It’s this broader epistemological stance that I’m “testing.”
Well I dispute this. See chapter 8.
One thing we see from the different ways people have responded is that what counts as evidence relevant to the issue is different depending on whether you accept A and B. For those who accept A and B, they treat it as at least a sort of prima facie evidence that can make C and the conclusion rationally plausible, ceteris paribus. Those who reject A and B are working with a narrower scope of evidence that naturally rules out C and the conclusion.
I have read that chapter, but will re-read it.
C2f is today evidence for common descent. But at some point in our ancestry the fusion did not exist. So whether or not Adam had the fusion would only indicate whether he existed prior to or after the fusion became fixed in our genome. By itself it would not indicate common ancestry. Actually, common ancestry would be determined by the genome as a whole.
Of course, in Adam’s case, the genomic finding would be false, because even though it would look like Adam shared common ancestry with humans “outside the Garden”, he didn’t.
Maybe it isn’t. But I thought we were discussing @swamidass’s claim that Adam was “human” and a genealogical ancestor of all humans now living. In his book he goes to great lengths to clarify that he does not mean Adam was “human” in any specific scientific sense, and in fact there is no single scientific definition of “human” in any event.
Nope. We were discussing @JohnB’s question about whether Adam would have had a fused chromosome 2. @swamidass’s theological humans have nothing at all to do with that question.
Even if we are talking about “humans” in a biological sense, how would we know whether a “genealogical Adam”, if such existed, would have a fused chromosome 2?
Strictly speaking, C2f isn’t necessary to the type of issue I’m pressing. It’s just the particular example that came to mind. If “the genome as a whole” indicates common ancestry then I can just ask whether Adam’s “genome as a whole” would have been significantly different than that of POG. If not, then Adam’s “genome as a whole” would have indicated that he shared common ancestry with POG. In which case, there would be evidence against Adam’s de novo creation, though not necessarily evidence against Adam being de novo created with evidence against his being de novo created.
Right… that’s really the only point I’ve been pressing on since I brought up the C2f issue.
OK, I see your point.
Yes, that seems to be part of @swamidass’s objective: To propose a scenario that is not subject to scientific falsification, even if it is also not subject to scientific verification.
That’s not my objective.
It just turns out that genetics is not as powerful as we thought. It would take intentional, perhaps miraculous, work by God to leave evidence of the de novo creation of Adam. I’m not “hiding” Adam, it’s just that genetics is a streetlight.
It’s not a biological question. We have no way of knowing anything about this hypothetical person’s genome except that it made him interfertile with other humans, whose genomes we do know about. It’s actually a theological question. Why would God have given Adam features of a chimpanzee genome rather than features of a human genome? Absent an answer, we should assume that Adam had a human genome, with a human chromosome 2.
No, there would be no evidence against de novo creation, because, given no expectation for that creation to have produced a different genome than common descent would, no evidence could distinguish the two hypotheses. That’s how science works. In order for evidence to be for X and against Y, the expectation for X would have to be different from the expectation for Y.