the other hand, bonobos, also a close relative of modern humans, was found to have more than two diploid copies of the AMY1 gene. Nonetheless, the bonobo AMY1 genes were sequenced and analyzed, and it was found that the coding sequences of the AMY1 genes were disrupting, which may lead to the production of dysfunctional salivary amylase. It can be inferred from the results that the increase in bonobo AMY1 copy number is likely not correlated to the amount of starch in their diet. It was further hypothesized that the increase in copy number began recently during early hominin evolution as none of the great apes had more than two copies of the AMY1 gene that produced functional protein. In addition, it was speculated that the increase in the AMY1 copy number began around 20,000 years ago when humans shifted from a hunter-gatherer lifestyle to agricultural societies, which was also when humans relied heavily on root vegetables high in starch. This hypothesis, although logical, lacks experimental evidence due to the difficulties in gathering information on the shift of human diets, especially on root vegetables that are high in starch as they cannot be directly observed or tested. Recent breakthroughs in DNA sequencing has allowed researchers to sequence older DNA such as that of Neanderthals to a certain degree of accuracy. Perhaps sequencing Neanderthal DNA can provide a time marker as to when the AMY1 gene copy number increased and offer insight into human diet and gene evolution. Currently it is unknown which mechanism gave rise to the initial duplication of the amylase gene, and it can imply that the insertion of the retroviral sequences was due to non-homologous end joining, which caused the duplication of the AMY1 gene. However, there is currently no evidence to support this theory and therefore this hypothesis remains conjecture. The recent origin of the multi-copy AMY1 gene implies that depending on the environment, the AMY1 gene copy number can increase and decrease very rapidly relative to genes that do not interact as directly with the environment. The AMY1 gene is an excellent example of how gene dosage affects the survival of an organism in a given environment. The multiple copies of the AMY1 gene gives those who rely more heavily on high starch diets an evolutionary advantage, therefore the high gene copy number persists in the population. Brain cells Among the neurons in the human