Describe it correctly - the (sudden?) abundance of spud-based food acted as a selection pressure on the people's genetics. Those who had mutations making it easier to extract energy from spuds (more amylase) were better suited to breed forward.
The spuds didn't change the genes as much as reward those with certain mutations. Unless, of course, the potatoes themselves were mutagenic...
Describe it correctly - the (sudden?) abundance of spud-based food acted as a selection pressure on the people's genetics. Those who had mutations making it easier to extract energy from spuds (more amylase) were better suited to breed forward.
The spuds didn't change the genes as much as reward those with certain mutations. Unless, of course, the potatoes themselves were mutagenic...