Ok so this says that a plant didn't spread to all regions so pack rats ate different foods - due to availability.
Was that correctly understood?
Ok so, because humans basically have unlimited possibilities of what they can acquire, we aren't limited to what foods have migrated naturally to us.. However- my theory to debate is, if availability defines changes like that, could we as humans not decide- I will limit myself to this or this and see if it causes mutations? Wouldn't it work similarly to building up a tolerance to allergens? But toxins?