Memories of the 28th Century

The basics of human evolution are pretty well known, but there is one matter that hasn’t been tied down, yet. That is the matter of tooth size, cooking, and diet; these are closely related, and they relate to digestion and metabolism. The earliest hominids and their ancestors had teeth that were similar to present day apes, including large canine teeth and larger molars (for grinding up vegetable matter. The large teeth were necessary to process coarse, hard foods such as nuts, and woody plants. Over time the teeth became smaller, until in H. ergaster they teeth were quite like those of modern humans.

There probably are several reasons for the teeth to become smaller, but more external processing of food before it was eaten probably was the biggest item, and the biggest break-through in the processing of food was cooking. It is interesting that H. ergaster lived from 1.8 to 1.3 million ybp, but there is little evidence of humans using fire until about 500,000 ybp; although there is a claim of evidence of fire use in Africa from 1.5 million ybp. If this is confirmed, then the little mystery of the difference in timing between tooth reduction and cooking will disappear. But the accepted dating makes it a mystery. When humans started cooking food, things generally became softer, so the large molars were not needed. Cooking also changed the chemical properties of some foods, and more nutrients became available.

With food becoming more digestible humans didn’t have to spend as much time and trouble in hunting and collecting. Cooking also made some plants that were barely digestible or even toxic edible and nutritious. One type of food that became much more nutritious was grass seeds. Without cooking the starch in grass seeds is not digestible, but it converts to the digestible form by being heated to about 100 degrees, at which point it slowly converts. A trip through a digestive system is enough for some conversion to happen, but barely enough to make it worth the trouble of chewing the seeds.

Cooking break downs the carbohydrates into molecules that are more readily digested. That was wonderful for hunters and gatherers, but it seems to be creating problems for people now, because the more readily absorbed carbohydrates sometimes lead to adult onset diabetes. I mentioned grass seeds, because they were first domesticates about 11,000 ybp; although they had been used for brewing since at least 23,000 ybp. Like the relationship between teeth and cooking, the relationship between brewing and bread making has been a matter of curiosity. The two processes use the same materials (Grain, water, and yeast), but the processes are different.

Putting things together we may be able to figure something out. While cooking may have started 1.5 million ybp, it probably wasn’t plant material that was being cooked, because human metabolism hasn’t become efficient in handling simple carbohydrates, and we can be pretty confident that humans would have adjusted to a diet high in simple carbohydrates within a million years.
We can see from the relatively high proportion of the population that has trouble digesting gluten that bread making came long after brewing ale. One would expect that the genes that lead to either celiac disease or a an inability to digest starches, would have become rare among people from cultures that made bread from wheat, and such for the last 30,000 years, but there still are quite a few people with those conditions. That suggests that the early breads did not affect people negatively, so it was the introduction of wheat about 9000 BCE. That suggests that the first bread was not from grain but from miscellaneous seeds, but 11,000 years should have been long enough for the genes that cause celiac disease would have become rare.

I have few conclusions here, except that the evidence points toward contradictory results. Humans probably have been cooking for about a million years, maybe as much as 1.5 million and certainly much more than 500,000 years. With all those years of eating refined carbohydrates people still have negative reactions to them. In addition, the early breads probably weren’t anything that we would call bread now, and it might be more reasonable to think that bread and ale both derived from gruel, thin mush of boiled, crushed seeds. It also appears that the gene pool really does retain things that should have been discarded for a long time.