© Nikola NevenovFILE: Bronze Age family harvesting grain. Some human populations gained extra genes to help break down starch in only 12,000 years.
Our bodies absolutely need carbohydrates for energy. It's a matter of survival.
Comment: The majority of humans do appear to need some carbohydrates in their diet, however, note that these particular adaptations appear to have occurred in just the last 12,000 years, so it seems that, whilst humans have been on the planet for at least 200,000+ years, their dietary needs, or more likely their consumption habits, changed relatively recently.
So much so, that some human populations have actually increased the number of genes that help break down starches and sugars over the past 12,000 years. In that time, Europeans have gone from an average of eight starch breaking down genes to over 11.
The adaptation tracks a shift from a hunter-gatherer lifestyle to a more agrarian one, as agriculture spread across Europe from the Middle East. High-carbohydrate staples like wheat dramatically increased in the human diet and the ability to efficiently absorb all of that energy was advantageous. The findings are detailed in a study published September 4 in the journal Nature.
Comment: The ability to absorb it more efficiently may have been advantageous when meat was, for whatever reason, more scarce. Because, otherwise, the data show that grain consumption for humans is. overall, deleterious.
Focus on the 'amylase locus'
Comment: Some groups of humans also evolved to be better able to digest animal milk components, like the fat, protein, and sugars, however it appears that, again, this was an evolutionary matter of survival. And there's evidence showing that these dietary shifts such occurred alongside significant climatic upheaval. So it may be that, at least for a period, the consumption of milk, relatively suddenly, became a necessity for survival.
Given how the archeological record shows how the adoption of agriculture had various deleterious effects on human health, and so it may be that these particular genetic adaptations for carbohydrates were also a matter of survival: