That’s a great article (by @Joel_Duff) on a really interesting new paper, thanks for mentioning! I agree with Joel that the findings are devastating to a “genetic entropy” argument. The most exciting and remarkable finding IMO is the fact that the researchers could rescue the deteriorating clonal lines by crossing them back (sexually) to inbred lines of the same strain. Here is one of many great paragraph’s in Joel’s piece, with bold added by me:
But here is what makes the study so powerful as an evolutionary finding rather than a creationist one: the researchers also maintained control lines of mice that reproduced sexually through sibling mating for more than 60 generations over the same 20-year period. These sexually reproducing mice accumulated far fewer mutations—approximately 22 SNVs per generation compared to 70 in the cloned lines, and far fewer structural variants. More importantly, the sexually reproducing lines showed no decline in fertility or viability across 60 generations. The sexually reproducing mice were fine. The clonally reproducing mice went extinct. This is not a story about genomes inevitably falling apart. It is a story about what happens when you remove the very mechanism—sexual reproduction with its attendant crossing-over recombination and subsequent selection on those new combinations—that genomes use to maintain genomic integrity.
Now I’d also recommend reading another piece of detailed analysis of these questions, with some great writing that highlights three “fears” surrounding the longstanding questions around mutation load. It’s still a preprint, and I don’t know when it will find a home in a journal. Disclosure: the first author is my (nonclonal) offspring. But honestly, I’m recommending it because of its clear discussion of the issues, both technical and (my word) ethical. Their findings argue strongly against “genetic entropy” and they explain why, but I think the implications are a lot more important than the refutation of largely dishonest folk science consumed in the pews. Enjoy: