It’s sort of amusing you guys are like - can’t you just take the typical creationist position on this? 
Sorry that I’m jumping in here, I haven’t followed the thread recently, figured I’d maybe read it later, but I was amused by that.
I’m not sure if I’m understanding the reasoning here, but I’d like to understand. How is this any different than other shared gene content?
It’s less amusing that you seem to have no idea what people are actually saying.
Nonsense question that shows you didn’t understand the point. Banding patterns are a type of visible similarity among chromosomes. The inference that similar bands contain similar genes is only reasonable given the assumption of common descent. Given separate creation, why should there be any relationship between banding and gene content?
You should probably note that scd thinks Purdom and Tomkins are wrong about it not being a fusion. Just to remind everyone of how this thread started.
Because banding pattern isn’t gene content.
Picture this: I’m going to give out a bunch of gifts, so I get out my wrapping paper. I can wrap identical gifts in the same paper, or different paper. So you see two wrapped boxes of the same size with the same wrapping, do they contain the same gift? They could, but they could also not. That’s creation. Evolution can’t work that way. The contents vary with the karyotype, you can’t get contents drastically different from the packaging without meeting certain recognizable and verifiable criteria and leaving certain forms of obvious evidence.
So scd has no basis for his assumption that the matching banding patterns are evidence of matching gene content, that inference requires an assumption of common ancestry.
I’m not even asking him to take a particular creationistic position. I’m trying to get him to understand why creationism does not, at least intrinsically, predict a chromosomal fusion merely on the basis of observing similarities between chimpanzee and human chromosomes.
Independent creation doesn’t predict a chromosomal fusion just because human and chimp chromosomes exhibit similar G-banding patterns.
Creationism is of course compatible with evidence that a chromosomal fusion occurred in ancestral humans, in the form of double centromeres, and/or telomere-to-telomere sequences in the middle of a chromosome. On creationism it is those facts and those facts alone that imply a chromosomal fusion occurred. But notice how any similarity to chimp chromosomes do not figure in this scenario.
That means there is a state of knowledge from which a chromosomal fusion is predicted by one hypothesis, but not by another, and another state of knowledge where one hypothesis is merely rendered compatible with the evidence. You have to understand this question about evidence, prediction, and compatibility from the perspective of background knowledge.
What you expect and what you can rationalize on different hypotheses depends on what you already know. Given certain background knowledge, common descent predicts(implies it should exist even before it is found) evidence of a fusion. There is no such prediction on creationism. However, if and when such evidence(double centromeres, internal telomeres) is found, creationism is compatible with it. It does not falsify or contradict creationism, it just favors common descent. Scd does not seem to understand this relationship between compatibility, prediction, and background knowledge.
700kya. Interesting! Thanks very much, @swamidass.
Perhaps it would help if you answer the question that @scd did not understand:
We find a single long chromosome in the human genome.
Why would a creationist believe this had once been two shorter chromosomes earlier in human history, which then fused?
Hi @CrisprCAS9,
Thanks for the link to that more recent paper. If 3 MYA is correct, then the fusion event probably occurred in some species of Australopithecus, shortly before the emergence of Homo 2.8 MYA. Cheers.
Does this surprise you?
Very likely, yes. At the very least it occurred a reasonable length of time before the divergence of the other recent Homo lineages.
Of course not. But every time I ask a question, he has to wave his hands that much harder, so it is all worthwhile.
I don’t know enough yet to answer the question. Looks like there were other things I misunderstood too, so I have more learning to do!
Fair enough.
Do you understand why someone who accepts common ancestry would easily come to this conclusion?
Yeah, they were looking for them in order to prove common ancestry.
So you don’t understand. OK, I was just checking! 
No. You should understand by now that science doesn’t deal in proof, it progresses by testing the predictions of hypotheses, which produce new evidence.
Even if that is true, that would not make the double centromeres and internal telomeres on human chromosome 2 pop into existence if they really weren’t there.
So even if the people who sequenced human chromosome 2 were already deeply convinced that common descent was true, and wanted to “prove” it before they had sequenced the chromosome, that fact does not somehow magically transform human chromosome 2 into one having that evidence on it.
No amount of putative bias or faith inside their heads is going to dictate to reality and change the DNA inside their sequencing machines.
He’s been waving furiously for many years now. He doesn’t seem to be getting tired.
I don’t think @scd or @thoughtful really understand what it means to find fragments of old telomeres and centromeres in a chromosome that, if common descent is true, would have been the result of the fusion of two smaller chromosomes.
I continue to wait an explanation of how a creationist would predict this finding, or what “Design” purpose it serves.
Bonus points for explaining why YEC’s try so hard to deny the existence of these things if they should be able to have predict them anyway.
Todd Woods thinks it’s a fusion…so why not take his view @thoughtful ?
It isn’t about him, it is about everyone else. My hope is that the more vigorous the hand-waving, the more obvious it will be to observers such that those who are open to changing their minds will be pushed away from such a weak position.
Or at least it will be amusing to others.
Well, the more I learn about genetics, the more I realize it’s more complicated than I thought and how many more things there are to learn. 
If you know where his explanation is located, please link.
Initially as a lay person, it would just be my assumption that changes in chromosomes are a bad thing - because that’s all I knew. So I would just have to ask a lot more questions - what are the parameters of when it’s occurred in animals before - especially among animals that probably would be considered the same kinds? Are there any sequences that look like telomeres and centromeres that aren’t?
I had remembered reading something that Tomkins had wrote that this fusion would be different than any others observed.
This idea is postulated despite the fact that all known fusions in extant mammals involve satellite DNA and breaks at or near centromeres. Only telomere-satelliteDNA or satelliteDNA-satelliteDNA are found in chromosomal fusion sites of living animals in nature, not telomere-telomere fusions (Adega, Guedes-Pinto, and Chaves 2009; Chaves et al. 2003; Tsipouri et al. 2008). While telomere-telomere fusions have been documented in the rearranged genomes of human cancer cells, these are not indicative of healthy cells but instead are associated with genomic instability (Tanaka, Beam, and Caruana 2014; Tanaka et al. 2012; Tu et al. 2015).
I have a lot more to learn before I could firmly take a certain view. Honestly, I don’t think anyone’s going to be affected much which view I take. I think genetics is surprising though. It’s really tough when I read something surprising though - is this observed? Is this based on an assumption of the current evolutionary model? Sorting that out is pretty much impossible at my level of knowledge right now. But I keep reading articles because they’re interesting.
For example, I was tempted to start a new thread about this one:
While searching genetic databases for the ancestral version of a human gene involved in gene regulation, CGGBP1, University of Toronto molecular geneticist Isaac Yellan unexpectedly found coelacanth strangely has many variations of this gene.
Even more unusually, these different variations of the CGGBP genes didn’t all share a common ancestor with each other. This suggests that at some points around 10 million years ago, 62 of these genes were swiped by the coelacanth from other, unrelated species - through horizontal gene transfer.
These genes, with their ability to ‘jump’ around and even between genomes a bit like viruses, are known as transposons.
Maybe should? But I figured I have to learn more about transposons first…