First contact: a lost tribe of the Amazon

These images were published today by officials of the Fundação Nacional do Índio (FUNAI), the Brazilian government's National Indian Foundation. Taken from a passing helicopter, the photographs show a tribe of Amazonian Indians, covered in bright bodypaint, taking aim at the helicopter with bows and arrows. This instantly piqued my interest.

It is estimated that there are almost a hundred tribes left on the planet who choose to have little or no contact with the outside world. Half of these are said to live in the dense Amazon rainforest of Peru and Brazil. Often so-called 'uncontacted' tribes have actually had encounters with the outside in generations past, usually in the form of prospectors and loggers. Since these experiences are almost invariably violent, the 'uncontacted' tribes are forced ever deeper into seclusion. According to Miriam Ross, spokesperson for Survival International, "First contact is often completely catastrophic for 'uncontacted' tribes. It's not unusual for 50 percent of the tribe to die within months after first contact. They don't generally have immunity to diseases common to outside society. Colds and flu that aren't usually fatal to us can completely wipe them out."

Now, their way of life is being threatened - not by helicopters, but by encroaching development. The forests are shrinking. As logging continues unabated in Peru, which has placed less emphasis on protecting areas for indigenous people than Brazil, these and other groups are forced across borders. Imaginary lines drawn in the mud by people they have never met, for reasons they do not understand. Distress. Disinheritance. Disease. Death. Welcome to the modern world.

For more on this fascinating story, visit Reuters or The Associated Press.

Paradise lost

As you've no doubt noticed, I've been a tad busy lately. I had to study for finals, did a load of microscopy, got my first tangible results in the lab, and went on a roadtrip across the Southwest US. Now I'm home, listening to the rain (and Róisín Murphy), but thinking about deserts.

When I was very young, I discovered an old book on the dark shelves of my grandfather's house during one of our December holiday visits. The text and photographs in this book detailed vanished cultures and the mysterious objects they left behind: the jungle ruins of the Maya, the moai of Easter Island, the standing stones at Carnac. The most arresting image in the whole book was of a gravel plain in the Sahara simply littered with abandoned millstones. That was the moment I realized that the environment is not a static thing: the Sahara was green once. Buried beneath its dunes and sand drifts lie intricate networks of river valleys carved into the bedrock. Some 10,000 years ago, the continued retreat of the European ice sheets of the last glacial period had shifted the monsoons to the north. This converted the plains of the Sahara to grassy savannah and covered the slopes of its mountains with forest. Humans settled in the area; the art they created illustrated herds of cattle and a menagerie of wild animals like antelope, elephants, giraffes and even crocodiles. About 6,000 years ago, the Sahara began to dry out again. Rock art from this period depicts the rapid loss of once-plentiful grazing land, as well as subsequent battles over the diminishing resources. The savannah and the forests are gone. The Sahara is a place for nomads now.

The Ténéré is a vast sea of dunes bordered by mountain ranges in the Sahara region of Niger. For centuries the Tuareg have run their azalai salt caravans through this hostile environment, traditionally with caravans numbering up to 20,000 camels - as witnessed by French colonial forces in the early 20th century - and using smaller convoys of off-road vehicles today. In this featureless wasteland, bereft of water and shade, grew a solitary, stunted Acacia tree. Even though its height was no more than three metres, it was visible from miles away. It became an important desert landmark, a sacred place for repose and the only single tree to be indicated on maps with a scale of 1:4,000,000. With its closest neighbours more than 400 km away, it was the most isolated tree on Earth: the last surviving member of the ancient Saharan forests.

In 1939, a well dug by the French military at the Tree of Ténéré revealed that its roots reached down to the water table, 35 m underground. To the Tuareg this tree, estimated at 300 years old, was not only a navigational point of reference but also a symbol of life itself, protected from harm. Not a single leaf was fed to a camel, not a single branch was broken for firewood. In his notes for 21 May 1939, Michel Lesourd, Commandant des A.M.M. of the Service Central des Affaires Sahariennes, wrote, 'There is a kind of superstition, a tribal order which is always respected. Each year the azalai gather round the Tree before facing the crossing of the Ténéré. The Acacia has become a living lighthouse; it is the first or the last landmark for the azalai leaving Agadez for Bilma, or returning.' A true miracle, this tenacious tree. So why am I writing about the Arbre du Ténéré in the past tense?

When Raymond Mauny travelled to the tree during the 1959 Berliet-Ténéré Mission, he noticed with alarm that the tree no longer resembled Lesourd's photograph from 1939 (above), noting that, 'It was the victim of an automobile accident; a military lorry, backing, had broken one of its principal branches. This branch had been sawn up and used, and the bit of trunk that remained had been trimmed. Is it not still considered to be taboo?'. Fellow explorer Henri Lhote, who had previously seen the tree in 1934 remarked, 'Before, this tree was green and with flowers; now it is a colourless thorn tree and naked. I cannot recognise it - it had two very distinct trunks. Now there is only one, with a stump on the side, slashed rather than cut, a metre from the soil'.

In 1973, an - allegedly drunk - Libyan truck driver lost control of his vehicle, veering off the road and right into the Arbre du Ténéré, the only tree in a 400 km radius. The tree did not survive this second collision. On 8 November 1973, the dead Tree of Ténéré was taken to the Niger National Museum in Niamey, where it can still be seen, caged off in a sad little enclosure. A sculpture has been erected where it once stood, a metal tree that doesn't require water, doesn't mind a couple of knocks. And so the slow and inevitable desertification of the Ténéré region was completed, albeit with a little help from us and our machines. The Sahara desert is inexorably expanding, drowning the Sahel to the south, reaching with sandy fingers towards the Mediterranean. Time brings change. Although not in our lifetime, or even that of our children's children, a time will come when the Sahara will be green once more, rest assured. In geological time, one wretched little tree means nothing, I know this. Yet I can't help feeling sad for its passing. Not in my lifetime. Not in my lifetime...

Photography credits: Ténéré desert landscape © Alessandro Vannucci; the Tree in 1971 © Peter Krohn; new tree sculpture © Shepherd family; Please visit these astounding photographers for more desert delights.

Banquet of the bizarre

A Saturday morning is perfect for wandering the stalls of your local farmer's market. Not only is it a great place to pick up fresh produce on the cheap, but it is often also a place where nutrition turns exotic. Markets, grocers and fruit 'n vegetable stalls are infinitely fascinating to me; there are always new varieties of old favourites and by now you've sussed that I'm a sucker for variations on a theme. There are often strange and wonderful new things that entice me: weird fruit from the tropics, or sometimes from someone's backyard; strange vegetable shapes that the Korean lady assures me you cook "like potato". The world is too big and life is too short to bore yourself with green beans and Golden Delicious apples. We should indulge in the variety of tastes and textures that sprout from the Earth (except for okra - that stuff's wholly inedible). So let me unpack my electronic brown paper bag onto my digital countertop here, and I'll share with you some of the virtual veg I scored at the Cyberfarms Cybermarket this morning. Be a love and put the kettle on, will you?

Romanesco Broccoli [Brassica oleracea var. botrytis]. Isn't this gorgeous? It's the mathematician's favourite vegetable, Romanesco broccoli. Which is technically classified as a type of cauliflower, not broccoli. Something to do with the maturity of the developing flowers, apparently. Cruciferous systematics aside, isn't it just the coolest thing? It has an alien symmetry. The whorls of florets have a fractal nature. Some people find it too pretty to eat. I don't: it's delicious simply steamed whole and tossed in butter with some pine nuts and crushed green peppercorns.

Tamarillo [Cyphomandra betacea]. Hailing from the forests of the Andes and now found in gardens everywhere, the tangy tamarillo is a delectable beast. Bursting with colour and zip, I used to eat these straight off the tree. Just don't try the bitter skin; the easiest way is to halve it and spoon the refreshing pulp within. Gorgeous with ice cream, they also make fine chutneys, jellies, jams and compotes. The best thing about the tamarillo is that you can get a giant fruit-bearing tree in as little as two years from seed. This explains why tamarillo seeds are such popular fodder in gardener trades, but also why the trees tend to be rather tender, with shallow root systems. Protect them from frost and strong wind and you too can have juicy freshness straight from the garden.

Water caltrop [Trapa bicornis]. Depending on your frame of reference, it resembles a steer skull charred by a brushfire, or the Baron of Hell from the Doom universe. The water caltrop is the seed of an aquatic plant, which grows with its roots anchored in the mud of lakes or slow-moving rivers. It was cultivated in China for thousands of years as an edible crop, and has recently regained prominence on the international food markets. They need to be cooked in order to be edible, and can then be used in an analogous way to the (unrelated) Chinese water chestnut. Water caltrops feature in several Asian dishes and I shall search them out at the Asian markets in Denver, although they do look rather intimidating, I must admit!

Horned melon [Cucumis metuliferus]. Hello, what's this? In essence, the horned melon is a cucumber gone psycho. Slice it open to reveal the green gelatinous inside, filled with seeds resembling those annoying underdeveloped white ones found in watermelons. Those who can overcome their fear of pips are rewarded with a refreshing taste somewhere between passion fruit, lemons and, well... cucumber. These beautiful and bizarre cucurbits grow in the red soil of the Kalahari desert and so represent one of the few commercial fruits - along with the watermelon - to have their origin in southern Africa. They'll make a colourful and surprising addition to any fruit salad, especially when combined with the white flesh and pink skin of the fabled dragonfruit, the pitaya.

Crosne [Stachys affinis]. Another Chinese introduction, and a member of the Mint family, no less. These made their way to France in 1882 and were long cultivated in the area of Crosne, whence the name. Crosnes are also known as knotroot because of these small, ridged tubers. They are kind of difficult to clean (a potato brush works best) and have therefore proved not to be very popular. However, they are very versatile and can be employed in roasts, or to add a nutty crunch to salads. Crosnes can be stir-fried in olive oil, then sprinkled with parsley and drizzled with a balsamic vinaigrette as a dish on their own.

Mangosteen [Garcinia mangostana]. The single most astounding fruit I ever had the privilege to taste. I found these at the famous Mercat de la Boqueria in Barcelona, and couldn't resist purchasing a couple. Dubbed "the queen of tropical fruit" by the American explorer David Fairchild in 1903, the dark, sexy rind full of tannins hides virginal white segments, resembling those of the orange. The biggest segments contain one seed each. They are originally from the Malay archipelago and historically did not travel well. However, mangosteens have been popping up on the dessert menus of fancy restaurants in North America, imported from Hawaii or Puerto Rico. Lucky foodies in big cities might even find them at the fresh food markets now, where they typically retail for about $10 apiece. And what did it taste like, I hear you ask? A combination of muscadel grapes, muskmelon, lychees, vanilla ice cream, raspberries, yellow cling peaches and somehow none of those things. In short, it tasted like mangosteen.

Tell me about the strange fruits and vegetables you've eaten, grown or fondled in some exotic marketplace. Links to pictures are welcome. More tea?

Photography credits: Romanesco broccoli © rattyfied; tamarillo © evag29; water caltrop © Exif; horned melon © Nadia McIlhany; crosne © @rgs; mangosteen © sasithorn_s. Please visit these talented Flickr users for more exotic produce.

Charlatans in white coats

So we all know The Ancients were whack jobs. They built pretty temples and sturdy aqueducts, sure, but they not only thought the world was flat with an edge you could actually fall off of, but also that the sun revolved around it, a notion which persisted until the arrival of that crazy Copernicus with his heliocentric theory in the 16th century. They also believed a sneeze was the gods' way of trying to tell you something and that perturbations in the relative levels of the four humours (black bile, yellow bile, phlegm and blood) were the cause of all disease and personality defects. Oh, and not to mention their hideously antiquated taste in orgies: pigs' wombs in brine? Stuffed dormice? I think we'll stick with mini pizzas and garlic dip, thanks.

Modern science is The Truth. None of it is made up. Ever. Second-hand smoke causes cancer because the researchers say it does. If scientists warn that global warming may kill us all, we do our best to lower carbon emissions. The laundry detergent in the commercial must be scientifically proven to be superior, because the actor is wearing a white coat. Oh, wait... The public perception of science can so easily be hijacked. Science is not infallible, of course. It is a construed version of The Truth, based on observational evidence. Good science is objective honesty, but can never be absolute. Therefore, science is not The Truth, but it provides an explanation of natural phenomena that is damn well closest to The Truth. And that's why butter is really bad for you one week, and then much better than margarine the next. As more evidence is gathered, science inches closer to The Truth all the time. Now you can visualize just how far we've come since the days of ancient history.

The problem with the public perception of science is two-fold. First: people equate science with The Truth. Second: people equate anything that appears technical with science. If it sounds sciencey, we should trust it, because it must have come from an expert who knows what The Truth is. Not only is this rationale utterly absurd, it is also exceedingly dangerous. We are preconditioned to trust those who seem like authorities, even if they have hidden agendas. And even if these so-called authorities aren't inherently evil, they may themselves fall victim to indoctrination, disinformation or - worse yet - delusions of grandeur. Dabbling with pseudoscience not only detracts from the slow crawl to The Truth, but can bring a whole nation to its knees.

Trofim Lysenko was born in 1898 to a Ukranian peasant family. He attended the Kiev Agricultural Institute from 1921 to 1925 and was posted at Gandzha agricultural experiment station in Azerbaijan as head of legume selection - whatever that is. Lysenko constituted the perfect fodder for the Communist Party to create a working class agricultural scientist to inspire disenfranchised peasants to embrace forced collectivist farming. Lysenko had lots of novel ideas: in 1928, he proclaimed to have "invented" vernalization, a revolutionary new technique for increasing the yield of crops. By storing wet wheat seeds in snow over the winter, the resultant seedlings would flower earlier. This is of course nothing new - many temperate species require a cold vernalization period in order to break dormancy. It's a natural mechanism evolved to help the plant survive the cold, dark winter and sprout in the spring. However, Lysenko claimed that his technique ensured that the offspring of vernalized crops would already be vernalized themselves, and not require a new round of cold induction. This would stave off the looming food crisis. Could the next potato harvest be enormous? He had the results to back it up. No-one bothered to investigate the experimental practices at his agricultural research station. In reality, a lot of his data was inconclusive, but none of it was closely scrutinized at that point. It was too good not to be true. He could fertilize exhausted fields without applying any fertilizers at all! Lysenko was no mere agronomist, he was an agricultural messiah.

Soon Lysenko became majorly influential in Soviet agriculture. Sound Russian plant breeding was shifted to the sideline as Lysenko's procedures were adopted. Much of his work paralleled aspects of Lamarckism. Lamarckian evolution is the discredited scientific theory that acquired characteristics can be passed on to progeny. This is akin to saying that a man who lost an arm in a car accident will go on to sire armless children. Lamarck's theory was a pretty good one for the early 19th century perhaps, but since that time Gregor Mendel and Charles Darwin had provided much improved explanations for how heredity and evolution worked. Lysenko put in a lot of effort in denouncing the burgeoning geneticists of his country. After all, they were playing around with the chromosomes of fruit flies and seemed disinterested in helping to feed the people. The proof that DNA was the genetic material was still some decades away. Such bourgeois academics were of little use to the Soviet government; Lysenko's research output was tremendous, with edible results. His promises were the best way of motivating the kolkhozniks to stay on the ailing collective farms. In 1940, Lysenko became director of The Institute of Genetics for the USSR Academy of Sciences. All so-called counterproductive scientific activities were halted. The study of Mendelian genetics was essentially outlawed. Scientists and researchers all over the Soviet Union were ousted from their positions, imprisoned, or sent to labour camps.

Dark days for science. Georgii Karpechenko, a cytologist and plant breeder, was arrested for "anti-Soviet" inclinations. He was sentenced to death and executed on 28 July 1941. The real reason for his execution was his affiliation with Nikolai Vavilov. Vavilov was a Soviet botanist and director of the Leningrad All-Union Institute of Agricultural Sciences. He was especially interested in finding the centres of origin of crops like wheat and maize. Because he realized the importance of preserving the genetic diversity found at these centres of origin for future plant breeding projects, he was responsible for establishing what continues to be one of the world's largest seedbanks. Vavilov was quite vocal and openly criticized Lysenko's non-Mendelian initiatives. This did not go down well and Nikolai Vavilov was duly arrested. He died of starvation in a prison in 1943.

"He is responsible for the shameful backwardness of Soviet biology and of genetics in particular, for the dissemination of pseudo-scientific views, for adventurism, for the degradation of learning, and for the defamation, firing, arrest, even death, of many genuine scientists." - physicist Andrei Sakharov on Lysenko, 1964

Lysenko's stranglehold on Russian agriculture continued well after Stalin's death and into the 1960s. However, the world had changed by then; mainstream science could no longer be suppressed. A case was brought against Lysenko in 1962 (by three physicists, no less). Lysenko's use of political power to silence opposition and eliminate his scientific opponents was condemned and his work criticizd as pseudoscience. Appeals for the restoration of the scientific method to all fields of biology and agricultural science pervaded the Soviet press. No longer immune to criticism, Lysenko was removed from his post as director of the Institute of Genetics at the Academy of Sciences and restricted to an experimental farm in Moscow's Lenin Hills. The Institute itself was soon dissolved. Trofim Lysenko passed away on 20 November 1976.

Science is not infallible, of course, because scientists are human. Inevitably, researcher bias clouds results: the desire to see the data support the theory - that human need to be vindicated and validated - is very strong. A hypothesis can only be rejected or fail to be rejected, never proven. Truly objective science will allow the theory to describe the data, and so bring us an inch closer to The Truth. That is the beauty of the scientific method. The fact that the guy on TV is wearing a white coat doesn't make him a scientist. Listen to what he is saying: does he juggle technical terms? Does he whip statistics out of clean air? How reliable are the references he uses? Does he rely on your innumeracy to convince you? Is this a conjuring trick disguised as statistics? In the 21st century, now that everyone's an expert, it is more prudent than ever not to become sold on the hype.