Marc Verhaegen wrote:

> "Revised time estimation of the ancestral human chromosome 2 fusion"

The problem is, as is my understanding, these kind of mutations are
fairly common, as far as mutations go, so the most likely answer is
that we're talking about TWO events and not one. So the scenario that
I imagine is that one population where such a mutation was common
met another -- both having acquired their prominence via the founder
effect? -- and it simply became fixed.

Why is this a problem?

There may have been more than one event, perhaps more than two.

More than three.

In fact, there had to be a huge number over the 2 million years (plus)
evolutionary history of our genus. Only most would have popped up
in an individual and gone away with their death... most.

-- --

https://jtem.tumblr.com/post/738823521702199296

Marc Verhaegen wrote:
>

Link and the *real* abstract

Abstract
Background
The reduction of the chromosome number from
48 in the Great Apes to 46 in modern humans
is thought to result from the end-to-end fusion
of two ancestral non-human primate chromosomes
forming the human chromosome 2 (HSA2). Genomic
signatures of this event are the presence of
inverted telomeric repeats at the HSA2 fusion
site and a block of degenerate satellite
sequences that mark the remnants of the
ancestral centromere. It has been estimated that
this fusion arose up to 4.5 million years ago
(Mya).

Results
We have developed an enhanced algorithm for the
detection and efficient counting of the locally
over-represented weak-to-strong (AT to GC)
substitutions. By analyzing the enrichment of
these substitutions around the fusion site of
HSA2 we estimated its formation time at 0.9 Mya
with a 95% confidence interval of 0.4-1.5 Mya.
Additionally, based on the statistics derived
from our algorithm, we have reconstructed the
evolutionary distances among the Great Apes
(Hominoidea).

Conclusions
Our results shed light on the HSA2 fusion
formation and provide a novel computational
alternative for the estimation of the speciation
chronology.

See figure 4 which compares results from the
literature and from their method

<https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-022-08828-7/figures/4>

"Please note, that each period calculated with the
timeframe overlaps the with time frames taken from
the literature"

The overlap is considerable except for gibbons.

Further:
"Overall, our results are consistent with the
literature reports..."