Richard Wrangham is a primatologist and professor of biological anthropology at Harvard University who, in 2009, wrote the book Catching Fire: How Cooking Made Us Human which goes over the role of cooking in human evolution. The video above goes over some of the key concepts for his hypothesis that the cooking of food, particularly tubers, liberated more calories from the food our ancestors ate which helped fuel the evolution of the human brain.
In the video, Dr. Wrangham goes over quite a few concepts. He discusses the ever-changing anthropological evidence for when mastery of fire started, how most species of animal prefer their food cooked when given the choice, and a new coming out with evidence of lower primates mastering fire.
The most interesting part of this video comes in the question portion at the end where Dr. Wrangham discusses micronutrients(vitamins and minerals) and the effect of cooking on them. While it is known that cooking liberates more calories from food, it also tends to destroy vitamins and minerals. An audience member questioned this and Dr. Wrangham's response was very interesting:
"...I've been focusing totally on one aspect of nutrition, and that is calories. And the reason I do that is because if you study wild animals, and if you think about hunters and gatherers, then calories are what really matters and I think that's for 2 reasons. One is that they are so important and so difficult to get, and the other is that vitamins are relatively unimportant in the wild because, with the diversity of foods that people tend to eat, they almost always get enough vitamins. I don't think we have a single case of a study of primates in which there is a shortage of vitamins in their natural diets. It's when you get in to agricultural foods, and you start eating...90% of your diet is cassava or something, that there is a risk of getting vitamin shortage of one kind or another or, in that particular case, a protein shortage...It's true you'll get fewer vitamins so if you have the kind of diet which makes you susceptible to low vitamins, you know, too much time spent at McDonalds, then cooking does matter."
I think this illustrates a fairly repetitive thing we see in human history. Often times, we have solved one problem only to create others. We found a way to create giant communities only to find out what happens when people live in large communities, communicable disease. We identified bacteria as a primary culprit in these diseases and saved numerous lives with antibiotics while at the same time destroying the healthy bacteria that live in harmony with us, potentially creating other issues such as IBS, allergies, and GERD. We processed rice by removing the husk which leads to the deficiency disease Beriberi, which comes from a lack of thiamin in a higher carbohydrate diet. Finally, we know the Sun causes skin cancer(Probably not), so we told people to stay out of the Sun and spray themselves with sunscreen to prevent skin cancer without realizing it also blocks synthesis of vitamin D3 that we make from the UVB rays that sunscreen blocks. The end result...a large population of people with low levels of a vitamin that is now considered a hormone.
With agriculture, we've made it possible to have unfettered access to foods we normally would only have seasonally. I don't think this is a bad thing, it's only bad because people make it bad. Having yearly access to foods high in nutrients is a great thing. But we don't make the best out of it. When people develop their diet based on only 6 or 7 different ingredients(Corn, wheat, soy, dairy, meat, and maybe a few vegetables sprinkled in there), and all of this food is cooked and processed so much that it's devoid of micronutrients, it shouldn't be surprising that health will suffer as a result. What is surprising is that people would find this surprising. If you take anything from this, it should be that diversity in the diet is extremely important to health.