Recently I came into closer contact with the philosophy of ‘sustainability’. We are thereby encouraged to waste less, grow more, use compostable products and recycle where possible. The health of the planet undoubtedly depends on our adopting a more thoughtful attitude in all aspects of living. But this philosophy seems to overlook one important aspect – ourselves. What could sustainability mean when applied to the human animal? Other animals sustain themselves instinctively – they behave in ways, developed through evolution, which ensure their survival as individuals, in groups and for the continuation of the species. Perhaps a better word is ‘conservation’: other animal species have evolved to ensure their conservation. Unfortunately, their natural inclinations are all too often thwarted by us, through domestication, destroying their habitats and introducing foreign competitors.

But how about us? What do we need to do to conserve ourselves, and to sustain our bodies and minds throughout our ever-increasing life span? As in previous blogs, perhaps the simplest approach is to recall what was essential to survival following the separation of our hominid predecessors from the primate line and the subsequent evolution of Homo sapiens. Our early ancestors were upright, migrant, opportunists with large brains capable of problem-solving, of retaining knowledge, skills and memories, of curiosity and of anticipating future events. They lived in small bands and, in order to find food and evade predators, migrated to most inhabitable areas of the world.

Settlements and agriculture are very recent changes in human behaviour; too short a time for evolution to make the necessary adjustments for living in dense conurbations where movement is restricted and brains are harnessed to solve entirely different problems, including that of living in harmony with thousands of the same species. We are still shaped to behave more like free-roaming cats or brumbies, than ants or bees. So what can we do to sustain our, as yet, un-evolved bodies and brains? What can be done to conserve our integrity as human animals? These issues will be addressed in further blogs.

When working as a farm veterinarian, I was constantly confronted by the primary importance of the female animal. It is the cows which produce the milk and the milk is used to produce a wide range of important foods and other products. The cows give rise to the calves which grow to become the next generation of milk producers. It is the ewes which are retained for their wool and to produce lambs. The sow and her production of piglets is of the greatest importance in the pork industry. It is the hens which lay eggs. Brood mares give rise to generations of foals and so on. Male animals are of lesser importance. They are the source of the semen used in fertilisation, leading to the production of calves, lambs, piglets and so on, but rarely deliver it ‘personally’. Most male calves barely survive birth, and those that do are only retained to grow large and be eaten.

On the other hand, most human cultures regard women as inferior to men. Women are confined to the home, have little or no access to education, play no part in the organisation of communities and are valued solely as providers of food and for the rearing of children. In many cultures, the women work while the men sit around and talk. Even in the ‘more advanced’ Western cultures, women strive to be taken seriously, are excluded from more prestigious positions and, even when doing the same work as men, are paid less.

It is time this imbalance is corrected. Women and men are equally capable of achievement in all areas of work and thinking; the much vaunted physical superiority of men is negated by the use of modern machinery and technology. However, equality is not the goal, but recognition. In fact, we men are inferior to women. Only they can produce the children which are needed to keep the human species in existence. They enable the start of new lives, protect and nourish the developing foetus, give birth to fully formed human young and provide their food for several months as they grow. Without women, the human animal, Homo sapiens, would become extinct.

The human animal is unique with regard to the amount of time spent in sleep – at least a third of every day. Lack of sleep has a serious effect on both physical and mental health. Research has shown that sleep occurs in phases with different levels and that dreams occur during shallow REM (rapid eye movement) sleep. There is still much to be found out about the function of sleep and dreaming. While asleep, memories appear to be consolidated; and dreaming seems to be necessary in the processing of emotions.

There is a further aspect of sleep which has yet to be even recognised, let alone explored. The importance of the colon and its friendly inhabitants to human health was commented on previously (see Your secret garden), and the reflex connection between the intake of food and defaecation explained. The products of bacterial digestion in the colon benefit human health in ways which have yet to be fully explored. But what has the colon to do with sleep?

During our usual eight or so hours of sleep, we do not eat or defaecate. By the time we are asleep the contents of the day’s meals have been mostly digested in the small intestine and the indigestible residues have reached the colon. Colonic fermentation then proceeds without interruption and the chemical products have ample time to be absorbed and reach all parts of the body. As in ruminants, such as cattle and sheep, and in many other animals, the day is an active time for eating and night a relaxed time for digestion.

Human sleep is undoubtedly important in mental health, but it may also be essential for physiological health that the fermentation process in the colon is completed and its products fully absorbed.

 

 

 

 

 

 

Studies in archaeology and anthropology describe the origins of Homo sapiens in Africa and how soon, in historical terms, we moved out of the continent into the Middle East, and on to inhabit the rest of the world. The scientific reports seem to dwell almost entirely on from where and when we originated. Today, in contradiction, there are detention camps full of refugees fleeing persecution; governments are rushing to build fences to keep out ‘illegal immigrants’; we worry about our borders and ‘boat people’, and the media encourages debate about the dangers of overpopulation. Everywhere, people on the move are seen as a problem.

A more important aspect of human evolution is the kind of animal we have become. We left behind the trees and jungles inhabited by our primate ancestors and ventured out onto the plains. Evolution has provided us with a vertical stature, long legs and bipedal gait, strong arms and shoulders, and above all a brain which can analyse situations, solve problems and plan a future. Humans are capable of moving long distances to find new resources, escape threats and to carry the means of survival with them. Prehistorical and historical evidence highlights the frequent movements of both small and large numbers of people across continents and oceans. We are migrant animals, only settling where there are reliable resources and when we feel safe from threat. However, the constant movement of people around the world over many thousands of years has resulted in the interchange of ideas, uptake of new technology and, ultimately, modern civilisation.

Modern nations and governments resist or highly control the entry of outsiders, as a stable population is believed essential for economic activities – work and the accumulation of wealth. Newcomers are regarded as disruptive and unlimited immigration threatens resources. Narrow nationalism and racial hatred are some of the outcomes of these policies.

We need a new political philosophy which regards migration, both inward and outward, as inevitable, valuable and essential to the further development of world peace and prosperity.

 

Today I picked up a brochure promoting a Holistic Wellness and Beauty Centre and was dismayed that the public are still being offered Colon hydrotherapy ($129) along with many other dubious and expensive treatments. Irrigation of the colon is claimed as beneficial to health. There is no scientific evidence that washing out the contents of the colon results in an improvement in health. The practice seems to have arisen from knowing the colon is the source of faeces, which are a waste product, and therefore ‘cleansing’ the colon should be a good thing. But this naive assumption ignores the normal function of the colon. It is a fermentation organ where those foods which are not digested and absorbed in the small intestine are broken down by bacteria. These bacteria are species which have evolved with us over perhaps millions of years and which produce chemicals of importance to health.

The importance of the colon ‘flora’ in human health has yet to be fully explored. Some bacterial products are important in preventing colon cancer and others seem to function in our immune systems. There are likely to be other ways in which they support health. The interaction between humans and the activities of our ‘secret garden’ is long established and has been refined by evolution. It is irrational and dangerous to break that connection through ‘cleansing’ without knowing the outcome. The health and survival of many animals depends on similar associations with benign bacteria, ruminants are a common example.

Instead of colonic irrigation, a more sensible approach to health is to ensure that the friendly bacteria in the colon are fed with a variety of substances which they need to survive and thrive. These include fibres, seeds, nuts, fruit peels and indigestible starches. Refined foods are mostly digested and absorbed in the small intestine. A diet which does not contain colon-friendly foods prevents this organ working efficiently, which may lead to problems such as chronic constipation, irritable bowel syndrome and colon cancer.

Don’t let them wash out your colon: feed your friendly bacteria with the right foods

The recent referendum and ongoing debate about whether Britain should remain in the European Union is more about nationalism than the realities of history. The human animals who presently inhabit these islands are derived from many previous populations. The first occupations occurred when there was no English Channel and England was part of Continental Europe. These early inhabitants interbred and were diluted by those who followed. So the ‘British’ are a mongrel mob descended from the Beaker people, Celts, Romans, Anglo-Saxons, Scandinavians, Norman French, refugees from European wars, previous subjects of the British Empire and all the other folk who arrived by boat, and later, by trains and planes.

As in most countries with a complexity of racial origins, there is a big variation in the colour of skin and there is no reason to claim that the inhabitant of a pale pink skin is superior in any way to others with different skin colours. A ‘white’ skin is purely the outcome of evolution. A certain level of radiation from the sun is necessary to produce Vitamin D in the skin.  Whiter skin soaks up more radiation and results in more Vitamin D. Darker-skinned humans are at a disadvantage in the higher latitudes and more liable to vitamin deficiency which interferes with bone growth. Vice versa, whiter skins are more liable to damage from excess radiation in the countries closer to the Equator.

A dark skin is the default condition for the human animal, which is not surprising since our immediate relatives, other primates such as the Chimpanzees, Bonobos and Gorillas, all have dark skins. A recent discovery has confirmed this. The skeleton of an individual Homo sapiens found in a cave in England, who was estimated to have died about 10,000 years ago (Cheddar Man) was sampled and the DNA analysis revealed he was dark-skinned and had blue eyes. It is likely that Europe and the UK was first occupied by humans with dark skins. The loss of pigment was a retrograde step in that ‘whiteys’ have evolved to survive only in the darker, colder areas of the world.

We all know about the ‘dead period’ after lunch, and it is the curse of those who try to be innovative, productive or just listen to talks in the afternoon. It is difficult to stay awake after lunch: our bodies demand a rest. From an animal point of view this is not unusual. Midday is when kangaroos lie in the shade of trees, when cows settle down to ruminate, predators rest from hunting, birds roost, and pet dogs and cats are least active. This is a time for renewal, for recovery after muscular activity and refreshment of brain function. We, and all other animals, need to nap.

For a variety of reasons, napping for 40-60 minutes in the middle of the day, is regarded as a sign of weakness. Perhaps it’s expected or OK for senior citizens (a ‘Nana nap’), but not for working people. Capitalism demands its pound of flesh – eight hours daily of productivity and a nap is seen as slacking off. But there is plenty of evidence to show that the period immediately after lunch is the least productive during the working day. Which from our animal point of view is not surprising: it is the time when we have evolved to rest and recover.

Southern European cultures have long accepted the inevitable, and siesta time is still part of the working day, but the pressure is on to change to a Northern European or American timetable. I doubt there will be a consequential increase in productivity, only in stress. If you have the opportunity because of being self-employed, or can persuade the boss to allow you slip away from the computer or workbench for a period, you will find that a 40-minute nap will result in sharper and more effective thinking, and an increase in energy which will last until its time to go home.

As a retired person, I hope you youngsters consider my advice, but we’ll talk about it again later…after my nap.

 

A previous blog – Music is in our genes, explained that the human voice, and singing in particular, evolved from the primate ability to vocalise. Primates such as the chimpanzee and gibbons make noises to keep in touch with others and to convey warning messages to the group: Watch out there is a snake below! An eagle is overhead! Lots of fruit to eat here! Through evolution we have retained and refined the primate vocal apparatus so that speech and singing have become important in creating and maintaining our social bonds, and communication through language underpins civilisation.

It is impossible to know precisely when languages first started and to a large extent why and how they have changed since. It seems that as the ability to speak evolved, different languages developed in isolation as humans spread across the earth, and possibly deliberately in order to enforce group identity. But when and why did singing develop? Music seems to have a very deep association with the human brain. People almost immobile with severe dementia often respond remarkably to music, becoming active and even dancing. Songs remembered from their youth are especially stimulating.

The act of singing is a unique human ability and it involves several physiological mechanisms. The brain controls the position of the vocal cords in the larynx and air is forced upwards from the lungs so that a particular sound or pitch is made. A sound is heard in the ears and this in turn is analysed by the brain and changes made in the vocal cords when the pitch has to be changed. This feedback loop is present in all of us but, all too frequently, is neglected or unrefined. Obviously, there are other mechanisms involved in controlling loudness, resonance, etc. However, interestingly, even those who claim not to be able to sing, regularly and subtly modulate their voices in conversation.

The unique human ability to sing brings other benefits. Singing, and to a lesser extent music in general, leads to the release of endorphins in the brain and, together with the improved oxygenation resulting from the increase in the depth and rate of breathing, makes us feel good. Singing is a powerful way to tackle depression.

Among animals we alone have an upright posture. This unusual stance did not occur by chance (yes, it is poetic!) but developed over many thousands of years and via several pre-modern human species. If an upright posture had been disadvantageous, it would have been discarded during evolution and there would have been no Homo sapiens. The question is: why did we evolve in this way? How did an upright stance enhance the survival of  early humans? It is easy to make up explanatory stories such as being upright enabled our ancestors to peer over the grasses and other vegetation on the African plains, and see potential game or predators in ambush. Perhaps having brains, eyes, ears and nose together at the top of one’s body results in better planning and management of the hunt. Or perhaps the head and brain is more easily cooled there. As the human body is adapted for rapid and steady movement over long distances compared with other primates, perhaps the thinking organ is safer when high up.

Whatever the origins of our unusual stance, we need to be aware that we remain a vertical animal and that our physical activities should accord with this position. Too much sitting or horizontal lying does not exercise the muscles which are essential to keep us upright. Lack of muscular action allows our long bones to deteriorate and become weak. The spine is supported in an upright position by several large muscles which need to be regularly exercised. And all these muscles are essential for returning blood from the lower body to the heart and then to the lungs and brain. The heart and circulation are kept healthy through regular upright exercise. Working for long periods sitting at a horizontal desk, or immobile at a standing desk, are not compatible with human health. We evolved as active vertical animals and need to keep our origins in mind at all times.

In the past, the evolution of Homo sapiens was viewed as a continuous progressive journey, without setbacks and that our cultural development was inevitable. We separated from the primate branch that led on to the chimpanzees and bonobos about 4 million years ago, and our ancestors gradually evolved bigger brains,upright posture and developed the ability to make tools, control fire, develop agriculture and so on. This simplistic narrative with its underlying inevitability is rapidly crumbling in the face of recent discoveries.

There were several, possibly many, pre-modern human species, with varying degrees of evolution of height, stance, size of skull/brain and facial features. Some developed the ability to make tools and several of these species lived at the same time – there was no smooth transit from one form to another. At some stage, perhaps a quarter of a million years ago, in East Africa, one of them evolved into H.sapiens, and a small number later moved out into Europe and Asia, but related species were still around. ‘Modern humans’ co-existed for a long time in Eurasia and interbred with at least two other species – Neanderthals and Denisovans.

So the human diversion from the primate branch on the tree of mammals, is no longer regarded as a single twig, but more like a small tangled bush. Evolution is a messy affair with no goal or purpose, and the outcomes are mostly the result of chance. The world could just as easily have come to be inhabited by clever dolphins, cunning capuchins, or rapacious rats. We have become the dominant species, but we need to be aware it was all due to circumstance, and evolution does not stand still.