add more gene conversion rates

[petrelharp]

Currently there's only GC estimates for DroMel. Let's get some more in! At least we can do HomSap; and probably GC rates are similar for other apes at least, so if there's not estimates for PanTro (or maybe even PonAbe) we could use HomSap estimates. I'm not sure what else is out there, but it'd be nice to get default values in for everyone if possible.

[dschride]

Trying to do this in HomSap and it is a bit dicey. We can probably say that the mean tract length is on the order of 100 bp (see https://elifesciences.org/articles/04637 and https://www.nature.com/articles/ng1287), which obviously isn't as precise as we might like. If we assume a per-bp rate of around 5e-6 (the elife paper cited above says 5.9e-6), then we get a rate of ~5e-8 tract initiations per bp per meiosis, which would give us a ratio of about 0.8, similar to Drosophila? We could decide to pull out something resembling point estimates from these papers (e.g. the midpoint of the mean length = 55–290 bp from the Nature paper cited above, which is from way back in 2004 by the way), but we probably shouldn't pretend that the resulting estimates would be super accurate.

[petrelharp]

Well, a best guess is better than nothing! Do you know a good expert to ask?

[dschride]

I am asking Justin Blumenstiel, who might know. Meanwhile, this Arabidopsis paper and some of the studies cited therein could be useful. Will take a closer look later, but linking to it here mostly so I don't forget: https://elifesciences.org/articles/01426