Wild horses couldn't drag us from the track

The betting shop on the main street in Malahide, where I live, does a roaring trade.

Coming up to a big race meeting, the place is a hive of activity. Gambling, a sort of tax on stupidity, is as old as mankind but there is a positive side to this vice; racing celebrates an animal whose ancient story is inextricably linked with our own. Horses helped to shape human history.

Our love of the nags goes back a long way: the Vogelherd Horse, 6 cm long from nose to tail and carved from a piece of ivory, was probably carried as a good luck charm by its Cro-Magnon owner; its surface is worn smooth from handling. One of the oldest sculptures known, this little figurine was carved about 30,000 years ago. Horses also feature among the beasts lovingly painted on the walls of the caves at Lascaux and Altamira.

About 4,500 years ago, tribesmen on the steppes of Central Asia managed to capture, break and mount wild horses, an extraordinary feat for that time. Horses were raced in the Olympic Games in 638 BC and Ben Hur-style chariot racing was popular in ancient Rome. Racing, in our part of the world, is a legacy of the Crusades: European knights shipped horses from the Middle East, which were faster than the ones at home. The thoroughbreds of today are descended from three Arabians; Godolphin Barb, Darley Arabian and Byerly Turk were brought to England between 1689 and 1724. Pitting horses against each other for a wager became popular with the nobility. The first racecourses date from the 18th Century.

But there is an irony in this adulation of the horse; this animal is a bit of a dinosaur. Ecologically, it's in the sunset of its days; the horse, together with its relatives the rhino and the South American tapir, are among the last surviving members a group of creatures which first appeared about 55 million years ago. The earliest 'horse' was about half a metre tall and lived in what is now Wyoming. Unlike its modern descendants, it had several toes, preventing it from sinking into the soft mud of the forested swamps where it lived.

The first open-plain grazers evolved about 17 million years ago. They had large eyes, all-round vision and long necks, with which to look out for enemies; high-speed escape was the survival strategy. The weight became focused on a single toe, the better to run over open ground. Ironically, horses became extinct in America; the wild mustangs of today are descended from domestic animals brought in by European colonisers.

But the horses and rhinos, with their odd numbers of toes, have been overtaken by creatures with even numbers of toes. The rival group, which includes the deer and cattle, have developed a super-duper digestive system. The tough cellulose walls of grass-cells are broken down in fermentation chambers, known as a rumens, at the start of the food-canal. The bacteria, having done the demolition work, pass on into the gut where they too are digested; nothing goes to waste in this highly efficient food conversion process.

Horses, however, are 'rear-end' digesters; the grass is broken down in the large intestine towards the end of the food chain. The bacteria are expelled from the body undigested, a loss of valuable energy and resources. Definitely the poor relations, the odd-toed tribe have lost out to the high-tech even-toed competitors; horses and their likes are a dwindling minority.

The famous wild horses of the Camargue are not descended from the animals depicted in the Dordogne caves, but from domestic animals which were allowed to go wild. The Camargue animals are white, whereas the horses in the cave paintings were brown. They also had short upstanding manes. These ancient horses were thought to be extinct. Then, a Russian army officer made a startling discovery.

Nikolai Mikailovich Przewalski organised five expeditions to Asia on behalf of the Czar and is credited with discovering various mountain ranges. In 1879, exploring a remote valley in Mongolia, he noticed a strange wild horse. Smaller than a domestic one, the animal resembled the beasts in the ancient cave pictures. It was of a similar dun colour, with a dark stripe and it had an upstanding mane. On a subsequent expedition, two small herds of the strange horse were sighted at the edge of the Gobi Desert but it was not until 1898 that the first two Przewalski foals were captured. In 1901, 51 foals were despatched to zoos in Europe. Meanwhile, the wild Przewalskis bred with wandering domestic horses, contaminating the pure stock. No Przewalski herds have been seen since 1967. The last reliable record of an individual in the wild dates from 1969.

In 1977, a Przewalski foundation was established in the Netherlands. Animals were acquired from zoos and a captive breeding programme got under way. It has been extraordinarily successful. By 1997, there were 61 Przewalskis in five special reserves. In 1990, a 10,000 hectare reserve was established in Mongolia and the first 16 horses were released there in 1992. By 2000, there were 150 animals on the reserve, which is now the Hustai National Park. In 2005, the conservation status of Przewalski's horse, the national symbol of Mongolia and the only wild horse in the world today not descended from domestic stock, was changed from 'extinct in the wild' to 'endangered'. Good luck at the track.