The headline, and the quoted comments, do not seem to me to be supported by the description of the findings.
It seems to say certain crucial parts of the genome are preferentially protected from mutation. That does not mean that those mutations that do occur are non-random. All it says is that not all parts of the genome are equally susceptible to mutations.
We already know there are repair mechanisms for DNA that reduce the damage that could otherwise accumulate from mutations. What this seems to say is that there are regions where extra protection applies, that's all.
I'd like to see the actual Nature article on this, seeing as the comments attributed to the researchers here appear at variance with what they have actually found.
Aha, got it, here's the abstract:
Since the first half of the twentieth century, evolutionary theory has been dominated by the idea that mutations occur randomly with respect to their consequences1. Here we test this assumption with large surveys of de novo mutations in the plant Arabidopsis thaliana. In contrast to expectations, we find that mutations occur less often in functionally constrained regions of the genome—mutation frequency is reduced by half inside gene bodies and by two-thirds in essential genes. With independent genomic mutation datasets, including from the largest Arabidopsis mutation accumulation experiment conducted to date, we demonstrate that epigenomic and physical features explain over 90% of variance in the genome-wide pattern of mutation bias surrounding genes. Observed mutation frequencies around genes in turn accurately predict patterns of genetic polymorphisms in natural Arabidopsis accessions (r = 0.96). That mutation bias is the primary force behind patterns of sequence evolution around genes in natural accessions is supported by analyses of allele frequencies. Finally, we find that genes subject to stronger purifying selection have a lower mutation rate. We conclude that epigenome-associated mutation bias2 reduces the occurrence of deleterious mutations in Arabidopsis, challenging the prevailing paradigm that mutation is a directionless force in evolution.
The key phrase is that mutations are said not to be "random
with respect to their consequences", i.e. occurring with equal probability right across the whole genome. But, as far as I can see, they are not saying there is anything non-random about those mutations that do occur.
But as this is not my speciality, I'd welcome comments from a biologist.
A very interesting article: thanks for posting.