The Guardian from London, Greater London, England • 13

MICRO GUARDIAN- PLUS THE WORLD OF SCIENCE Thursday May 16 1985 13 After decades of official scoffing, it seems that the medicine man did know what he was doing most of the time. Norman Myers reports on the fascinating link between tribal lore and the forest plants that have entered the Western pharmacopoeia Shamamlsmni withouut every 9,000 persons (as compared with Britain's one to 500 or so). According to a former Health Minister of Zimbabwe, Dr Herbert Ushewokunze, himself a qualified doctor and a spiritual medium, "The traditional healers can All a lot of gaps. They are particularly useful with psychosomatic conditions, cases of asthma, tuberculosis, burns wounds and venereal diseases." In Tanzania, dozens of medicine men have been selected for training and by the Government as "medical auxiliaries," or front-line health agents, to work in cooperation with the national health service. Their traditional skills are checked and assessed by the Medical School of the University of Dar es Salaam, whereupon they receive instruction in several modern medical techniques, including personal hygiene, nutritional guidance, and a basic understanding of sanitation.

are trained to recognise the most common diseases, such as malaria, measles, tuberculosis and gastroenteritis; and to learn what they can do to counter 'them by way of first-stage help. So they are equipped with such basic items as thermometers, blood-pressure gauges and simple drugs such as aspirins. More importantly still, they are taught that preventive medicine is more beneficial, as well as far cheaper, than curative medicine; and during' periodic refresher courses, they learn how to take part in preventive vaccination campaigns, supervised by visiting health experts. Of course, all "difficult" cases they encounter in their bush surgeries must be referred to district health centres! Obviously the basic goal is to enable the best of the scientific and the traditional systems, the Western and the Third World systems, to work together. As a WHO report puts it: "An integration of the two systems, without compromise of principle yet with full understanding of both sides, should enable the sorely underprivileged populations cine men in ways to systematise and formalise their knowledge, and likewise to eliminate various forms of "malpractice." In line with this general approach, the Central Drug Research Institute at Luck-now, India the site of a recent seminar on medicinal Slants organised by the nited Nations Industrial Development Organisation is fostering over 100 university-level teaching centres for traditional medicine, plus 156 research units.

The Government of Burma has established a central research organisation that, exploiting the "knowledge resources" of the country's tribal healers, has identified 700 plants with apparent medicinal benefits. In Thailand, the government has set up 15 schools of traditional medicine in Bangkok alone. The Mexican Institute for Study of Medicinal Plants has documented a host of herbal remedies, from both forest and desert plants, used by the Aztecs for a variety of ailments, and apparently possessing unusual properties to treat cardiovascular, diabetic and parasitic problems. It was Mexican medicine men, after all, who drew Western attention to dios-genin, a major source of cortisone for use against rheumatoid arthritis, sciatica, dermatitis and Addison's disease also used as a critical constituent of the contraceptive pill. Of course it is in China that the greatest progress has been made.

For several decades, traditional medicine has been officially accepted alongside modern medicine. China apart, it is in Africa that greatest efforts are being made to integrate the two systems. The University of Malawi is mobilising the skills and experience of that country's medicine men; and the universities of Lagos and Ife are doing the same in Nigeria, working in association with the National Association of Medical Herbalists. Similar initiatives are underway in Zaire, Cameroon, Kenya and Zambia. In Zimbabwe, a medical squad of 800 Western-trained physicians is being expanded with over 4,000 African healers who are now registered as semi-professional practitioners all the more pertinent in a country with only one fully-trained doctor for that lies within the financial reach of impoverished millions." This health-care initiative parallels recent discoveries that the witch doctor often knows what he is talking about.

According to Professor Siri von Reis Altschul, a Harvard University authority on traditional medicine, up to half of the drugs in native medicinal repositories "actually may cure or provide relief if not necessarily for the reasons given by local tradition." Of 482 plant, species known to be used in Ethiopia as internal remedies for infestations such as tapeworm, roundworm, elephantiasis and bilharzia, almost 30 per cent have been shown, through scientific testing, to be effective to various degrees. According to Dr Oku Ampofo, director of the Centre for Scientific Research into Plant Medicine at the University of Ghana, local tribal healers- achieve much success with herbal therapies for shingles, a skin infection against which modern medicine has no answer. Ampofo has also investigated a plant used by Ghanaian medicine men against malaria and urinary infections. He has found the plant harbours a compound similar to quinine, as well as an antibiotic. Now the plant's effectiveness has been documented, its drug is being 'administered in the form used by traditional healers, viz: as roots soaked in water.

After extensive screening programmes by Western scientists, the director general of WHO, Dr Halfdan Mahler, asserts that "many of the plants familiar to the 'witch doctor' really do have the healing powers that tradition attaches to them. The. ages-old arts of the herbalist must be tapped There is no doubt that the judicious use of plants in primary-health care can make a major contribution toward reducing a developing country's drug bill. An army of traditional healers and herbalists can help to make attainable a goal of health care for all by Jthe year 2000." This diagnosis is all the more acceptable when we recall it was through follow-up to clues discovered in bush surgeries, that pharmacologists came to recognise the potential of the Madagascar rosy periwinkle THE medicine man of the developing tropics has long been revered by his fellow citizens. He has also been reviled by western doctors.

He is now coming into a fresh phase. Third World leaders want him to contribute to modern health services. During my 24 years of wandering around Africa, Asia and Latin America, I have frequently encountered medicine men this being a blanket term for herbalists, -witch doctors, faith healers, shamans and others who draw on tribal lore to concoct drugs from wild plants, and occasionally wild animals. I have been struck by the dozens of techniques displayed, just as I have been surprised at the hundreds of plants utilised, ostensibly with some success. Two convergent trends are now gaining momentum in the health arena of the Third World.

First, new strategies are being sought for the medicinal needs of the great bulk of Third World populations. By reason of cost and lack of professional personnel, most of the Third World cannot hope to' enjoy dev-eloped-world health facilities for many decades to come. So there is growing reliance on "green medicine," i.e. plant-derived drugs and pharmaceuticals. Secondly, and closely related to the first trend, the image of the medicine man is being steadily rehabilitated in many countries, now that scientific evidence is emerging that not all his cures are quackeries.

Less than 10 per cent of the Third World's three billion people live within walking distance of a modern health facility. For most of them, the traditional healer, with his herbal treatments, is their only contact with medicine of any kind. So it makes sense to mobilise the skills of local people at village level, with their accumulated knowledge of local materials, rather than putting emphasis on a limited network of high-tech facilities in urban areas. In the words of Dr. Ch'en Wen-Chieh, Chinese assistant director-general of the World Health Organisation: "We now hope that developing countries will make better use of medicinal plants as a means to become self-reliant, since this is an appropriate health technology that accords with the cultural heritage and natural resources of countries in question and Kef an medicine man from Colombia.

Inset: Ethnobiologist Conrad Gorinsky countries, notably Indonesia, Burma, Nigeria, Tanzania and Peru, are starting to upgrade the practices of traditional medicine men in order to integrate them and their iskius imo nauonai neaun-care systems. 1 The main strategy to date lies with training- establish ments which serve a double function. First of all, they encourage traditional seers to offer their extensive stores of knowledge in the service of public health facilities. Secondly, they instruct medi tive "pill." The team often finds that a sound bet lies with the hundreds of anti-fertility concoctions administered by tribal shamans; and 225 sound candidates have been identified from folk-lore medicine. For instance, the greenheart tree of the rain forests of Guyana has long served, according to Dr Con- bt Bartholomew Medical School in London, as a reli- able contraceptive.

All this is little surprising, of course, when we reflect that a good Coming up for air It's a great big world if you're really small The smaller you are, the bigger your share of the universe. Robert Walgate admires the hidden depths of the landscape EVERY part, every cell of the body requires oxygen for its survival, and for this reason we are dependent on haemoglobin. This is a highly complex molecule which is packed in the tiny red blood cells, and avidly absorbs oxygen from the air in our lungs. In this way the vital gas is transported by the blood circulation to all organs and tissues. It follows, of course, that the developing foetus also requires oxygen, but because it does not breathe in the womb it must obtain its oxygen from the mother's blood.

Strangely, but for very good reasons, foetal haemoglobin is chemically different to that found in the red blood cells after birth. No one knows just how the bone marrow stem cells, which produce the red cells, switch from making one type of haemoglobin to another around the time of birth. A recent report (Nature 313: 320, 1985) suggests that there is some inherent developmental clock which resides in the stem cells themselves. In every minute drop of blood there are about a million red blood cells, and by extrapolation one can calculate that in the five litres of blood pumping through our bodies there are about 25 billion red blood cells in all. Then take out all the haemoglobin from them, weigh it and the scales would nearly tip one kilogram.

If one could look at a single molecule of haemoglobin with the naked eye, one would see a spherical shape made up of four sub-units and in each sub-. unit there would be a protein attached to an iron containing structure; the iron is responsible for mopping up and transporting the oxygen. Now, in foetal haemoglobin two of the four proteins linked to the lone quarter of all prescriptions in the advanced world derive directly or- indirectly from plants. So much for the two convergent trends in Third World medicine. What can be done to promote the cause of the medicine man? Following a World Congress of Folk Medicine in Peru in late 1979, leading to the establishment of the International Association of Folk Medicine, there has been an outburst of initiatives in many parts of the developing world.

Several sion of not unity, but about one-and-a-fifth (1.2), meaning that it wanders about a bit, getting towards filling a surface (dimension two). Now, for the first time, the York group has shown by observation that the surfaces of plants are fractal curves. northern and southern blocks, each variety will on average over the 30 trials experience about as many wet conditions as dry ones. So conclusions drawn from average yields over the series will be more reliable than if they were based on single trials. Moreover, even if we can explicitly allow for differences in wetness, we would still use a modified form of randomisation to help allow for the myriad other factors which affect growth.

We would return to dividing the trial into a wet block and a dry block, but we would now also sub-divide each block into two plots, one for each variety. The randomising device would be used to allocate varieties to plots within wet blocks, and separately within dry ones. Fisher's technique has been enormously successful in practice, and not only, in agriculture. A great deal of mathe as a source of two potent drugs against leukaemia and other blood cancers. Tribal healers have led the way to the discovery of the painkillers morphine and codeine, both from the opium poppy; and of quinine, still the most effective drug against malaria, derived from the bark of the cinchona tree.

The WHO Task Force on In-1 digenous Plants for Fertility Regulation of Human Reproduction is seaching for materials to manufacture a safer and more effective contracep THE surfaces of plants, on which the million denizens of the insect world roam, are "fractals," surfaces that seem to have more and more nooks, crannies and area the closer one gets to. them. And this means that the world is literally bigger for small creatures than Targe ones: there's much more roaming to do when you're small. It's not just that you're smaller in the same-sized world. The world is actually bigger! This apparently crazy result means there can be many more small creatures on a plant than might otherwise be suspected, concludes a group of three biologists and a mathematician at the University of York.

But first, what is a fractal? The term was invented by mathematician Benoit B. Mandelbrot to describe lines and surfaces that were "self-similar:" ones that look exactly the same under a magnifying glass as without. That is to say, iron a large scale a "self-similar" line looked like a zig-zag, then on closer inspection each apparently straight segment would also be a tiny zig-zag and so on and on. Such lines can be infinitely long within a finite space. Mandelbrot showed that coastlines, for example, were fractal.

(After all what ts the length of a piece of coastline? How many coves and peninsulas are to be taken into account? Should we mark round each rock? Each grain of sand? At each increase of detail the length of the coast gets greater). Such lines and surfaces (think of a mountain range) can be thought of as "more" than (respectively) one and two dimensional because their chaotic wandering can take them almost anywhere, and their length and area cannot be measured uniquely. The lengths and areas depend on the scale of measurement Moreover, a fractal line (like a doodle) might cover a surface, or a chaotic surface (like pragmatic recommendations to farmers. Much of the skill in designing trials of this kind is scientific common sense a nebulous concept which might be difficult to clarify rigorously, but which, again, works well in practice. You do not, for example, plant your trial on ground that is excessively dry, or wet, or sunny, or shaded.

In particular, you try to make sure that each variety experiences a range of conditions. If one variety always appeared near a bank of trees, and the other did not, then the first would, be disproportionately exposed to being eaten by birds. But there remain many problems of design which cannot be settled by common sense alone. Imagine (simplifying matters greatly) that you can divide each of the 30 trials into a wet block of land and a dry block. Then the common-sense approach would be to ensure from one of the fundamental human rights: the right to health." Dr Norman Myers is a consultant in environment and development.

Sex by the light of the silvery moon Paul Simons considers an extraordinary case ofunderwater lunacy IT pulls the oceans into tides, sheds light with which night animals can navigate by, and perhaps makes lunatics out of us. There's even one remarkable animal, a Japanese deep-sea lilv. that liberates its sex 'cells once each year- in October at about 3 pm, on tne day of one of the moon's quarters. Some plants are also cast under the lunar spell. In their natural sea habitat, the sperm and eggs of many seaweeds are tossed into the water at high tides, when they can try their luck at cross-fertilising with their neighbours.

Even in a laboratory far away from the sea, the seaweeds depend on the moon for signalling the start of their breeding. But precious little is known about now the lunar rhythms in animals or plants actually wnrk. Various ideas have been suggested: the seaweeds dry out at low tides, the plants feel the changes in water pressure, or tney sense me cnanges in light during the tides. But none of these explains how the same olants continue a lunar cycle in the laboratory. So something much more deepseated must be behind plant lunacy, and a report in the journal Botanica Marina (vol 27, pp 467-472) points to a new answer.

P. A. Mooney and J. Van Staden studied a group pi piani normones, cyioiunins, in me sea wracx sargassum heterovhullum. The levels of cytokinins were monitored over a 28 day period and the first thing they found was a surge from the non-sexual to the sexual fronds, closely tied with the four phases of the moon.

The sex cells themselves were shed in a number of Sulses, at intervals of 13-14 ays, and coinciding with the lowest spring tide shortly after new and fuirmoon. The shed-dings were immediately preceded by the surge of cytokinins in the reproductive fronds, but as yet we can't be sure that the cytokinins actually triggered tne release of the sex cells. However, this marks an imnortant steo into. working out how lunacy in Wants actually works it may hold the key to many other lunar rhythms as well. of a plant would need a line with a fractal dimension not of one, but one-and-a-half.

(Thus lines on plants have a higher fractal dimension even than a coastline). What does this mean for biology? A great deal. It means, literally, much more room for life. It means that smaller and smaller creatures have a larger and larger world to live in. Not only does a small insect get more room simply because it is smaller within the same space it actually gets more space.

Thus, consider an insect and another ten times smaller. If a leaf were "mere-ly" a two-dimensional surface one might pack 100 of the smaller insects (10 10) into an area each of the ten-fold larger insects takes up. But because the surface is fractal, its area increases on the smaller scale by three to ten times, according to the York results. This gives room for 300 to 1,000 of the smaller insects in the space of the larger one. Figures available for the sizes and populations of insects on plants agree with these conclusions, the York group says.

And the studies may also be significant for. evolution. Because more area means more world, and increasing fractal dimension of the environment through the break-up of the continents, for example means more room for life, more environmental niches, and hence more species. Thus perhaps here lies a possible explanation for the slowness of early evolution (when for three billion years algae dominated the seas). Perhaps then the fractal dimension of the Earth was low, and niches few.

Later, a geologically-induced increase in fractal dimension might have triggered an increase in speciation, and hence evolution's rate. this non-repeatability the variance of the results. A recent study in Edinburgh of some 15 years of data from variety trials in the UK has concluded that only 9 per cent of the total, variance now comes from differences inside individual trials among plots with the same variety. In other words, unaccounted-for differences among sites and years contribute 91 per cent of the uncertainty in making inferences from the series. The next step, on which we are currently working, is to improve the design of series of trials.

And that, to come back toouropening question, is as it should be. If there is one piece of advice which a statistician would give to scientists, it is: never do anything only once. Dr Lindsay Paterson is at the Unit of Statistics of the Agricultural and Food Research Council at the University of Edinburgh. Green peach aphid on home territory sub-units are different to those found in the adult type. This difference means that foetal haemoglobin can take up oxygen more readily, and ultimately this helps the transfer of oxygen from the mother's to the baby's blood.

But what tells the bone marrow stem cells to stop producing one type of haemoglobin protein and switch to the manufacture of another type around the time of birth? Obviously this switch involves a change in the genetic expression of these stem cells, and this could occur either by an inherent development clock in the cells themselves, or by an inductive process stimulated by the changing environment in the growing foetus. When bone marrow cells taken from foetal lambs of different ages were infused into adult sheep whose own red cell production had been stopped, the foetal cells did not immediately start producing red cells with adult type haemoglobin. Instead, the switch only took place when the foetal cells reached the age at which the change would normally have occurred in the womb. This finding shows that an adult type environment does not stimulate the switch in haemoglobin production, nor does the foetus provide a stimulus just before birth this would have been circumvented by the transplanting. Instead, the bone marrow cells somehow sense their own age and make the appropriate adjustment in genetic expression, regardless of their environment.

Just quite how cells are preprogrammed and time their own genetic events remains an intriguing question. Saffron Davies This is a vast problem, which has attracted a vast literature from scientists, philosophers, statisticians, and sociologists. BUt perhaps the best way to approach it is not at the theoretical level. More revealing is what scientists have done in practice to overcome it. After all, even though the philosophers may not nave solved the problems of inference, science still manages to do experiments and to produce results.

Our barley experiment still ultimately lead to our beer or our whisky. First, though, let's make an important distinction. We are dealing in our example (and throughout this article) not with pure science but with technology. The barley experiment is not a unique investigation of the genetic structure of living matter (say), but likely to be one of around 30 roughly similar trials spread throughout the country whose aim is to a crumpled piece of paper) fill a (volume. Mandelbrot devised a measure of this apparent extension of the dimensionality of lines of surfaces, and called the result the "fractal" (for dimension of the object A coastline, for example, has a fractal dimen The agricultural scientist and the healthy growth of randomisation By photographing vegetation in springtime at various magnifications, and investigating numerically the wanderings of the outlines of the plants, Drs John Lawton, Mark Williamson, David Morse and the mathematician M.

M. Dodson discovered that a true drawing matical research has been done on the kinds of random patterns which are valid, in the sense of guaranteeing that the trials will indeed give the right average results. And computers have superseded tossed coins. Nevertheless, leaving anything to chance is only a last resort Randomisation is most appropriate when we genuinely have a long run of very similar experiments. Unfortunately, we only ever have an approximation to that.

Trials differ in soil and climate, for example. These differences loom larger in importance now than when Fisher wrote, because the design and management of individual trials have improved. The quality of a series of trials can be assessed by the extent to which results are not identical between different plots of land sown with the same variety. Statisticians call that each variety is planted on the wet block in half the trials, and on the dry block in the others. The problem is that we might not be able to say which is which.

Perhaps information about wetness is too expensive to collect; or perhaps we cannot predict at the time of sowing what conditions will be like later in the season. We then use a technique called randomisation, invented by R. A. Fisher in the 1920s. The simplest device for randomising is a coin.

In our ignorance of precise conditions, we divide our trial into two blocks by some easy guideline, such as the northerly and southerly halves. For each trials we toss a coin. When it comes down heads we plant the first variety on the northern of the trial and the second on the southern; when tails, we do the opposite. If there are significant differences in wetness between They don't call it trial and error for nothing. Lindsay Paterson ponders the pitfalls of farm' research WHAT justifies scientists drawing general conclusions from individual experiments? Suppose, for instance, that you have an experiment to compare the yields of two varieties of barley.

You grow them on a Eiece of ground near Edin-urgh in the summer of 1985. After lots of careful management and measurement you conclude that the first variety is better than the second. But how do you know whether the conclusion applies any more widely than to that place at that time?.