Whilst their food would not of changed in source, the content would of had spikes above global average it periods of time due to the atomic spike, also how that

Whilst their food would not of changed in source, the content would of had spikes above global average it periods of time due to the atomic spike, also how that dispersed and how long until equilibrium would all be factors that come into play. Let alone natural hotspots from solar radiation increase near the poles. But then the error +/- rate would seem to accommodate those kind of margins, but always nice if there is a way of narrowing those margins, so may be a field of research that has some headroom and also help learn many other tangents and maybe another data point for historical solar radiation.