BIO220H1 Chapter Notes - Chapter 2: Amylase, Starch, Hydrolysis

• School: UTSG
• Department: Biology
• Course: BIO220H1
• Professor: John Stinchcombe

Document Summary

Reading article 2 demeter"s legacy: rapid changes to our genome imposed by diet. Farmers had to adapt to benefit from energy-rich food from farming. Natural selection increased copy number of gene that codes for starch-digesting enzyme in farming population. Genetic adaptation to new diet since agricultural revolution. But in archaeological records find farmer"s bones anaemic. When initially transition from hunter-gathering to farming: lots of disease b/c farmers not adapted to new diet, caused deleterious digestive disorders. How did they adapt to new food supplies: cultural adaptation. Could process foods (cook/ferment) to increase digestibility: genetic changes. Gene encoding enzyme for starch hydrolysis adapted to increases in starchy food. Suggest that low amy1 copy number = ancestral state in humans. Amylase concentration was probably initially low in saliva of hunter- gatherer. A vita daily amount of cereals and milk. Human groups independently acquired extra copies by positive selection, not shared ancestry: a lot of high amy1 copy number in unrelated populations.