 Contrasting this analysis however a study of the spatial distribution of obesity across the mainland USA showed that once the effects of poverty and race were accounted for there was no association between ambient temperature and obesity rates.The most highly cited alternative to the thrifty gene hypothesis is the drifty gene hypothesis proposed by the British biologist John Speakman.This idea differs fundamentally from all the other ideas in that it does not propose any selective advantage for the obese state, either now or in the past.