What about Noah and Population Genetics?

[swamidass (S. Joshua Swamidass)]

@Otto

It seems ENU (N-ethyl-N-nitrosourea), which is known to produce point mutations, and has been studied with mice, should give us a good reference for the whole class of point mutation inducers (we don’t have to care for the infinite number of possible causes if we can rule out the whole category):

ENU is not a good either. Keep in mind that we see far more transitions than transversions:

ENU is an alkylating agent and has preference for A->T base transversions and also for AT->GC transitions.[5] However it is also shown to cause GC->AT transitions.[6]
ENU - Wikipedia

We would see that in the data, but we do not. Instead, we see this:

From: Common Descent: Humans and Chimps / Mice and Rats - #28 by swamidass

So before we do any more work to work out math or plumb the literature, it might be worth trying to find a mutagen or mechanism that can increase mutations in precisely these ratios. I’m not sure if one exists.