AWe like to think we have control over our bodies, but the opposite is often true. Such is the case with 'circadian desynchrony', a condition more commonly known as jet lag. Exhaustion, headaches, difficulty concentrating, light-headedness, trouble falling asleep or staying asleep; these are common effects of jet lag. They have the power to ruin a vacation or business trip unless you learn how to trick your own body.

BExperimental psychologist John Caldwell has spent most of his career researching the effects of sleep deprivation and sleep restriction, while also studying countermeasures that sleep-deprived people can use to function better. Much of his research was conducted within the military community. Caldwell explains that while our bodies are able to adjust to about one time zone change per day, jet lag sets in when we cross three or more of them because it creates chaos in circadian rhythms (otherwise known as our body clock). That's a fairly new phenomenon, historically speaking. 'People now can fly from New York to Paris in nine, ten hours, whereas in 1923 you did it on a ship and it took you six days to get over to Europe,' Caldwell says. 'We just haven't evolved to the point where we can rapidly change those rhythms, because it's a relatively recent thing.'

CBecause of the problems your body has naturally adapting to time-zone changes, you need to manually adjust your body clock, and that means changing your bedtime to be better matched with the destination to which you're traveling. Ranit Mishori, a professor of family medicine at Georgetown University School of Medicine, travels frequently to Europe, Africa, and the Middle East. To be ready to work when she arrives, she starts adjusting her bedtime two to five days in advance to match the local time at her destination. 'That means going to bed earlier when going east and waking up much earlier,' she says. When she returns to the US, she does the same but in reverse. John Caldwell creates a timetable that includes meetings, bedtimes, and social activities so that he can easily see what time it is at home and at his destination and plan accordingly.

DCircadian rhythms are influenced by natural light. While travel may disrupt those rhythms, you can help get them on track by regulating the amount of light that your body encounters, says Pradeep Bollu, associate director of the University of Missouri Health Care Sleep Disorders Center. When traveling east, your biological clock will be behind: '… avoiding bright light in the evening can help with advancing our biological clock,' he says. 'Similarly, bright light … after waking up also will help advance our biological clock to suit the new time zone.' When traveling westward, he adds, the biological clock is ahead of the latest time zone. He suggests gravitating toward bright light in the evening, if possible, and exercising to stay awake later and sleep longer.

EOne suggestion that is sometimes made is taking the hormone melatonin, which is a substance that is produced every night by the human body and helps you sleep. 'Taking a very small dose helps to recalibrate its release so that it is in sync with the time zone of your destination,' says Kern Singh, a spine surgeon in Chicago with Midwest Orthopaedics at Rush. Singh says he takes five milligrams of melatonin – which you can buy in pill form in supermarkets and many mainstreet stores in the US – on the plane and then again when he lands.

FHaving a glass of wine on the plane may sound tempting, but it could negatively impact your sleep, which could worsen jet lag, says Quay Snyder, president and CEO of Aviation Medicine Advisory Service of Centennial, who advises pilots on staying in top condition while in the air. 'It definitely has a sedating effect as far as getting someone to sleep, but it destroys their rapid eye movement (REM) sleep so their actual mental recovery is reduced,' he says. Instead, he says, be sure and have plenty of water so that you stay hydrated while traveling.

GBruce Stephen Rashbaum, owner and medical director of Capital Center for Travel and Tropical Medicine in the District of Columbia, regularly advises patients on jet lag. He considers prednisone, which is a powerful prescription medication, to be the most effective tool for jet lag recovery. He instructs patients to take the medication when they land, which is typically early in the morning, and again in the late afternoon and the next day. 'It is this simple ritual that works nearly every time,' he says. So if in doubt, you can always ask your doctor for some assistance. Everyone responds to jet lag differently. For those who suffer, the first week will be the most challenging, but after that, your body should start to recover.

How to Tame a Fox (and Build a Dog) is written by Lee Alan Dugatkin, an American evolutionary biologist, and Lyudmila Trut, a Russian professor of evolutionary genetics. The book describes the scientific effort to domesticate Siberian silver foxes – a project that Trut has been involved in as lead researcher for more than 50 years. When the project began, its purpose was to shed light on how dogs had gradually evolved from wolves, and silver foxes were chosen because they are the wolf's close genetic cousins.

There is much material to cover in the book, but the authors condense this without sacrificing any significant details of the project. The introduction reveals the end product of the experiment by describing the behavior of some very tame foxes that willingly interact with humans. This revelation, however, does nothing to lessen the reader's fascination. Indeed, the authors do an excellent job of expressing the joy of discovery of those early years of genetic research.

Interwoven with descriptions of the project and the astonishing changes in the foxes are the personal stories of the people involved, an approach rarely taken in scientific books, but one which works extremely well here. A major figure to appear in the book is geneticist Dmitri Belyaev, who first set up the domestication experiment in 1952, and who invited Trut to join the project in 1959. Trut continues his work today at their research facility in Siberia, where winter temperatures reach -40°C. Her team endures the harsh conditions because they obviously care deeply for the science and the animals they are in charge of.

The evolution of the wolf into a dog has long puzzled scientists. How did wolves first come in contact with humans? Why were some wolves less averse to humans than others? To answer these questions, Belyaev devised an experiment to 'breed the wild out of the animal' on an accelerated timeline.

As lead scientist at the Central Research Laboratory on Fur Breeding Animals in Moscow, Belyaev was less interested in the official line of research and more interested in the impact of domestication on animal genomes. After moving to Siberia, he obtained some foxes from a fox farm for a breeding experiment. He chose less aggressive foxes that did not immediately try to bite their caretakers. At the earliest stage of the experiment, he felt it was necessary to hide his activities from his superiors at the Central Research Laboratory.

Initially, 12 foxes were chosen, and within three breeding seasons the pilot study produced preliminary results. Some pups were not consistently aggressive; sometimes they even appeared indifferent toward people. These results were enough for Belyaev to hire Trut, then studying animal behavior at Moscow State University. Her job was to select the foxes for breeding and record details of changes. Among the eighth-generation foxes, a couple were calm enough for Trut to pick up. These, along with others that were slightly calmer than the rest, were selected for breeding as part of a larger project.

Repeating the selection for the tamest foxes in each succeeding generation, Trut and Belyaev noticed new behaviors. The first milestone occurred with a fox named Ember. Tail Wagging had never been recorded in foxes in the wild or captivity; it is the behaviour of dogs signalling happiness. One day Ember wagged his tail when Trut approached. He was the only pup of his generation to do so, but this generation was also markedly calmer than any previous one.

By the sixth generation of the larger project, pups displayed new behaviours. They pressed against the front of their crates seeking human contact, licked hands, and whined when people left. Fox pups whine for food from their mothers but had never done so for humans. Nor had they been documented licking hands. The pups exhibiting these behaviours were put in an elite group for breeding. Pups that did not exhibit these behaviours, or only occasionally exhibited a few, were maintained as a control group.

Belyaev and Trut made further observations. Instead of standing straight up, the elite pups' ears flopped over. Their snouts shortened, and some developed curly tails. These traits made them more visually appealing to humans. In short, over the generations, the foxes began to resemble dogs. It was then discovered that domestication creates complex interactions between genes that influence physical traits and genes that influence behaviour. But how did this domestication happen with ancient wolves? Belyaev theorised that naturally calmer wolves approached people in search of pieces of animal meat and bone they had discarded. As these calmer wolves interbred, the animals were no longer aggressive towards humans. This theory makes more sense than older ideas, which proposed that neolithic people stole wolf cubs so they could be trained to assist with practical tasks such as shepherding, guarding and hunting. For Belyaev and Trut, their new theory answered the question of how we got from wolf to dog, but not how we then got to a faithful four-legged family member.

Trut proposed to further chart the domestication of foxes by raising a fox called Pushinka at home. In time, Pushinka began differentiating between Trut and her colleagues, and other people who only seldom called at the house. Pushinka and her pups announced strangers' arrival with a bark no other fox had exhibited. So far 57 generations of foxes have been bred, and researchers have begun recording and decoding the vocalisations they have developed.