The worst thing that can happen to an arboreal being is to have the trees removed. 10 million years ago the capricious telluric forces put our ancestors on the ropes . The appearance of the Rift Valley blocked the entry of rain clouds from the Indian Ocean and the eastern part of the lush African forest began its transition to a savannah with some poorly distributed acacia. In fact, this ecosystem had been developing for millions of years in the latitudes close to our jungle, that is, there was a whole list of animals with millions of years of evolutionary advantage to occupy these new territories. Our ancestors were destined for extinction… or so it seemed. Of course they painted coarse in these new conditions, since There was always a bug that was much better than you when it came to running, smelling, hearing, attacking, biting…
Did we have a chance?
But faced with the need, it was necessary to reinvent itself. The prehominids were not having their best moment in an ecosystem that was not theirs and surrounded by much better adapted animals. His mediocre qualities seemed his condemnation in a place like the African savannah, but still one was not so mediocre. These ancient primates had lived in community for millions of years and few things stimulated the brain more than the development of the complex interactions established between individuals who share existence. So our cranial capacity was a little bit better than the rest, nothing exorbitant either, but a little hope where to hold on. So from that moment on, evolution favored those individuals who were naturally born with a greater ability to memorize, imagine or transgress. It was what differentiated us from the rest and represented the only possibility of survival. The evolution was very slow, plagued by continuous challenges, but little by little the subjects with more possibility of establishing complex relationships with their peers, of planning or of using the environment in their favor were perpetuating themselves and transferring those abilities to their descendants. In a few words: we were making big heads. We went from the 450 mm³ of the humble Australopithecus to the superb 1500 mm³ of Sapiens. Not bad. Something like changing a simple utility for a latest generation Ferrari, but the Ferrari must be maintained.
Afford the Ferrari
But you buy a great car and at first you are not aware of what its maintenance costs. Insurance, fuel, not to mention repairs with original parts… a fortune. The human brain with only 2-3% of our body weight needs around 20% of oxygen and about 50% of glucose . Of all the energy we produce, 20% goes to this demanding neuronal mass and this has largely conditioned our caloric intake.
But it’s not just quantity, but quality. 70% of the brain is fat, and within that fat, omega-3 fatty acids play a fundamental role, specifically DHA (docosahexaenoic acid). This fatty acid is essential: our metabolism is not capable of manufacturing it and we must necessarily take it in our diet . There are numerous studies that relate correct brain development with adequate levels of DHA both in our diet and in that consumed by our mother in the fetal development that preceded us. What’s more, a recent study published in the journal ‘Neurology’ states that people who consume more omega-3 fatty acids have higher brain volumes, something that in old age is equivalent to preserving our brain health for between one and two years.
Cannibalism as a solution
DHA is not found in all foods, although it is especially abundant in oily fish: sardines, salmon or tuna . White fish contains it to a lesser extent, but its concentration in species such as cod, hake or sole is also notable. Other sources are of plant origin: nuts such as almonds, chestnuts and especially walnuts are rich in omega-3, as are some oils of plant origin such as flaxseed and olive.
But this varied combination of foods was not always available to our ancestors . About 40,000 years ago we were in the middle of one of the numerous glacial pressures that have gripped the planet during the Quaternary. The ten-month winters made it extremely difficult to access certain foods, specifically, the necessary amounts of omega 3 would only be guaranteed during the short summer period. Support in the harsh winter would depend on several species of animalslike the aurochs, the deer, the reindeer, the bison or the horse. In particular, reindeer, which is one of the meats with the lowest DHA content that exists. This must have entailed enormous pressure, since the deficit of this fatty acid produces alterations in the functionality of the membrane in the neurons and this modification supposes the appearance of dysfunctionalities such as depression, aggressiveness, schizophrenia and other mental and neurodegenerative pathologies.
The researcher at the University of Almería, José Luis Guil-Guerrero, reveals in a recent publication how ancient Europeans managed to survive the transition from the Middle to the Upper Palaeolithic. That survival depended on a cannibalism that would supplement our deficits . It doesn’t sound like a particularly exciting dietary strategy, but survival instinct takes precedence over any other ethical considerations. Fortunately , time changed about 12,000 years ago and the custom of eating the neighbor stopped being fashionable.. Although we must remember that fashions are cyclical, like the glacial periods, not to mention the climate change that is currently taking place and whose consequences are impossible to foresee. Of course, the current change is towards a higher temperature, so what happened in the last glaciation is not foreseeable. Well, not so fast, because a study has just been published by the ‘Journal of Archaeological Science’ that just points in that direction. So it seems that cannibalism has been something more than an exceptionality in our evolutionary history and a resource when the things get ugly.