( ncluding Renaud Kaeuffer and Denis Réal...)Remote sheep population resists genetic drift

Haute Island sits in the Kerguelen Archipelago in the southern Indian Ocean and is more than 3,000 kilometres from its nearest port. The French government has used the island as a military outpost since the early 1900s, with French settlers arriving in the 1950s.

The Haute Island mouflon descended from two Corsican mouflons taken from the Vincennes Zoo in Paris in 1957. Mouflon are a hardy and fecund species of sheep, with the ewes able to produce an average of more than five offspring in a four-year lifespan. The Haute Island mouflon population peaked around 700 in the 1970s and since then has bounced between 200 and 600.

Coltman and his colleagues were able to trace the DNA of the original Haute Island mouflon couple using some samples of teeth, bone and fur that had been preserved from the Vincennes Zoo since in the 1950s. DNA samples from subsequent generations were taken from the mouflon that had been kept as hunted "trophies" in the 1960s, and then scientists arrived in the '70s and began collecting samples themselves.

"The Haute Island mouflon have presented us with a rare opportunity," Coltman said. "There may be other natural populations that may have been studied in a controlled environment over the years, but I don't think there has ever been one in which you've been able to trace the DNA of the original, founding couple."