Evolution of Human Diet and Human Brain

Human Diet has changed a lot during past few million years and some major changes were made just few thousand years ago after evolution of agriculture. But does those changes have any impact on development of our brain. Human are the best race on earth and ruling the planet only due to superior brain. Nutrition plays an important role for our health and brain, and understanding the evolution of human diet can help us better understand this topic.

There is a belief that we are not evolved to eat what we are eating today. Here we will try to evaluate that how much of such belief is valid. A few scattered tribes of nomadic hunter-gatherers are still living on our planet and they are still using the same diet as their ancestors did thousands of years ago. Researches on these people found that they don't develop high blood pressure, atherosclerosis, or cardiovascular disease. Does it mean that diet of those nomadic hunters is still best for us ?

Evolution of Human Diet

• From Stone-age (2.5 Million Years ago) to prior to Agricultural Revolution (10,000 Years ago) all humans evolved to eat food collected by hunting and fishing. [1]
• Our direct ancestor Homo erectus used to cook meat using fire around 1 million years ago. [2]
• Neanderthals evolved from Homo erectus around 250,000 years ago used to spice up their diet with herbs. [2]
• According to a controversial hypothesis by primatologist Richard Wrangham, 1.9 Million Years ago Homo erectus were found to have very small teeth, a small body and a much larger brain. There changes were attributed to cooked food. According to Richard Wrangham, Homo Sapiens could not have been formed without cooked food. [2]
• Dairy products, beans and cereal grains were introduced into our diet after invention of cooking and agriculture.
• According to some researchers, apes (who are considered our direct ancestors) used to depend on plant based diet only. Evolution towards human species started when they started eating calorie rich meat. It made their gut smaller and brain got sufficient energy to grow bigger over time. [1]
• Agriculture was developed around 10,000 years ago and we started to grow crops. [1]

Why did humans started agriculture ?

• Agriculture provided us a reliable source of food, that we can store for years.
• It gave us relief from risky hunting schedule.
• Cooking made cultivated vegetarian food easily digestible and made us extract enough energy from that.
• It made humans settle at a location instead of roaming all over and grow their families.
• After evolution of agriculture the birth cycle get reduced to 2.5 years from 3.5 years, which increased human population.
• Agriculture made humans a social animal.
• It gave us sufficient time and opportunity to develop other skills which evolved our intelligence.
• Most of the scientific developments in human history happen only after evolution of agriculture. So it must be the key.

In the process of evolution humans have changed their diet a lot from veg to non-veg and then back to a combination of both. Now humans are eating a wide variety of food. We have got both types of teeth which suits both veg and non-veg diet. Instead of giving logic to say that our diet is better, we should understand that humans developed due to these changes in diet and we are fit to eat any type of diet, depending on what is available around us. You can't expect a person living on poles to survive on vegetarian diet as it is not available there.

Note: Today no vegetarian is dying due to lack of nutrition and they are getting sufficient calories to power up their brains. Non-vegetarians have got their own logic and vegetarians have their own logic to prove their diet better. But the truth is that we eat what our families have eaten from past few generations. Even if you tell someone that their genes tell that their ancestors were nomadic hunters, he/she won't start eating like them. It is because our present beliefs, religion and emotions won't allow us do that.

Reference:
[1] https://www.nationalgeographic.com/foodfeatures/evolution-of-diet/
[2] https://www.newscientist.com/article/mg23230980-600-what-was-the-first-cooked-meal/