A key difference between the diets of Homo sapiens and our closest extinct relatives H. neanderthalensis is the ability to effectively digest cooked starches, with some evidence found linking cooked starch and a further increase in H. sapiens brain size. Roots and tubers were introduced into the broader human diet, and can likely be assumed to be associated with fire as cooking would likely be necessary for many tubers to be digested. The use of root and tuber species in some Hunter Gatherer cultures makes up a critical component of diet. This is not only for the nutritional value of the species, but the relative annual stability of the species. This buffer effect would be important for many groups that relied on tubers. The ability to process starch is linked genetically to modern humans, with the genes necessary to its consumption not found in H. neanderthalensis. The timing of this mutation on modern humans is important as it means the ability to digest heavily starchy foods has only developed in the last 200ky years. In addition to the exploitation of tubers, another dietary innovation (this far) of Homo sapiens is the introduction of coastal and other marine resources. Some researchers have argued that the introduction of shellfish and other marine species play a significant role in the evolution of modern Homo sapiens.
