Evolutionary Fitness ~ Addendum

In the previous article in this series we saw that our evolution as modern humans was hinged upon a particular adaptation, which was the development of our extraordinarily large bums. This enabled us (or rather our ancestors) to become the only species capable of true upright posture and bi-pedalism which at moderate speeds of locomotion only cost ¼ of the energy as quadrupedalism. This adaptation plus a few other benefits of upright posture led us along the path towards our development of larger brains and with it, the brains particular requisite needs and amazing abilities. We also saw that, at the time the most efficient method of providing the nutrient and energy dense food for our growing brains was through the consumption of animal tissues which required the use of hunting; particularly the persistence hunting that requires phenomenal endurance.

However, this is one tiny snippet of our ancestral past that largely dictates our physiology today. If you read that piece and began to realise the gulf between many of our lives today and the physical environmental stress of our forebears, then bear with me as we explore the rabbit hole a little deeper.

I’m sure you can appreciate that our evolution occurred over a fairly expansive period of time in which the environment that our ancestors lived changed considerably, both from the natural change in the landscape and climatic conditions, but also due to the migration necessitated for survival. So please appreciate that there is no single specific activity or type of diet to which our ancestors would have been exposed; it would’ve been a variable environment to which our ability to adapt was our saving grace, but there are some generalisations we can infer from the evidence.

Let’s look at the physical activities in which our ancestors had to engage to survive. We have already seen that persistence hunting required travelling distances of up to 20km per day in order to cause the heat load and exhaustion of the prey which made it easier to kill. This was mainly performed by males; the females however were not simply maxing and relaxing back at the shelter waiting for the male to return with sustenance. They were involved in very vigorous activity, arguably more vigorous than the males.

From the available evidence it is proposed that compared to the average distance travelled by males (15-20km) per day during hunting expeditions, females often covered 45-60% of the distance (9km). As you may have surmised already we still haven’t introduced the word gathering yet, and this is where the real action is at. The 9km covered mainly by females was not a contemplative stroll around the grounds before heading home for tea and scones. It was an extremely labour intensive essentiality that was a crucial source of nutrition that buffered the intermittent nature of the more nutrient dense animal food.

We will visit the food element of this arena in a later article, but for now we need to appreciate the physical effort needed to gather sufficient and appropriate non-animal foods was not akin to a day at a ‘pick your own’.

The principle non-animal foods were shoots, roots and leaves. The second non-animal item would’ve been nuts and to a much lesser extent, seeds, with fruit eaten seasonally. The roots, especially the root tubers, are the most annually available food as they are protected from the changes in above, or shallow, ground changes in environment, but this causes a problem for the gatherer. What problem? They are usually buried 5-6 feet deep in the ground. I don’t know about you, but in a previous life I worked in construction and digging holes 5-6 feet deep, even with modern tools, is tough going. To do this with either your hands or rudimentary tools would be an imposing task to put it mildly.

And you’d probably be engaging in the 9km digging-fest filled trek, with a minimum of 7kg in tow. Why this additional weight? It’s likely that you would be carrying a baby concomitantly, and also useful materials such as firewood with which to return to the shelter. While on the subject of returning with essential items, please bear in mind the males were not simply going for a walk/ run, wearing down the animal prey and killing them…job done; they also had to bring the animal back to the shelter and process the kill, both of which would’ve been fairly monumental tasks.

So both males and females would’ve been engaged in, on a daily basis some sort of lower (not low) intensity activity for fairly long durations and also fairly intense activities for slightly less duration, but still a prolonged period of time. This is in addition, as mentioned in the previous article, to the acts of shelter creation and maintenance, tool making, food preparation, climbing and periods of very high intensity physical activity such as evasion of predators aka running away…fast.

So, am I saying that we, as modern humans, need to be covering 9-20km per day, while resistance and/ or gymnastic training for multiple hours. Not at all. Our ancestors ‘had’ to engage in this level and type of physical activity for survival. We now have the ‘luxury’ of not even needing to have to move out of a 10m radius to exist, should we choose to go that route; our genome, however, doesn’t thrive in that condition. Our body does require a certain amount of stress in order to express the genes that create pretty optimal conditions for a healthy, high performance body and mind. But that doesn’t mean we have to engage in the exact type and amount of activity, nor as we shall see the exact food intake, of our ancestors. Both in physical activity and diet there is scope for a range of nuances, although there are fundamentals that do need to be acknowledged.

The key point addressed in the previous article, still remains true, our genome evolved in a very active environment, where nutrition was hard come by, and it still requires this stimulus today, except we continue to have to kowtow to our environment, albeit today not so much dictated by Nature, but certainly culturally. This cultural demand generally mandates that we are cooped up inside, sat at work stations for a minimum of 8 hours per day, with an additional 2 hours or so, spent in similar conditions commuting to and from our places of work. This leaves 4 hours per day maximum, outside of sleep, in order to do all of the other activities required in life which includes cooking meals and supporting our families; especially the very young and old members. This leaves very little time to fit in the significant amount of physical activity we have just covered.

So you can’t realistically replicate your ancestral past exactly, nor would you want to either. I’ve shown previously that our genome is so amazingly adaptive that if you begin to ‘up the ante’ for a short period, especially in the face of food restriction, our genome has no problem in accounting for this via a metabolic shift; it evolved to deal with this exact environment. If you set up this situation and then go back to your old lifestyle then this metabolic shift will bite you in the a*se. So be careful with the eat less/ exercise more concept, especially if it’s a self imposed temporary situation of increased activity combined with nutrient deprivation; you’ll probably end up achieving the opposite result of the one you nebulously set out to accomplish.

A better way to go about it is to determine the lowest amount of activity you can honestly sustain long term and then feed yourself sufficient high quality food so that you can perform this activity to a high level. I like this phrase to sum up the idea, and it’s a useful question to ask yourself daily ‘Have I taken my MED’s* today?’ This seemingly simple question will, if you do it, literally transform the lives of the majority of people. Will it create elite performers? Unlikely, that would take a little more of a precise approach, although surprisingly, not too much more. But for the greater part of the population a MED approach would result in a massive improvement in the health, performance and happiness of the nation. Make sure you get yours.

*Minimum Effective Dose (MED) required to produce a healthy body and mind.