Comment by teravor

    > acts on the molecular, cellular

this is rare and even more difficult to understand.

https://en.wikipedia.org/wiki/Structural_inheritance

basically, the genes do not generally contain blueprints but rather processes utilizing existing cellular machinery. a "mutation" can occur in a machine which will allow a propagating difference.

and there is nothing special about populations. it's merely the only way to observe most changes. gene frequencies in gene pools.