Female Komodo dragons do not need stem cell technology and genetic engineering to do it. They really can skip the male chapter in the case of breeding. Two Komodo dragons have hatched at the Sedgwick County Zoo, Wichita, Kansas, without the contribution of a male. These are the first dragons born by parthenogenesis in North America.

Parthenogenesis ("virgin birth") is extremely rare amongst vertebrates. In many insects - such as the plant lice - it can be generalized. And it can be found amongst some small lizards, such as rock lizards, whiptails and geckos.

Two other known parthenogenesis cases, in Komodo dragons, occurred at the London and Chester zoos in England, in 2006. The young in the American cases were DNA tested, as there was a remote chance that a male's sperm had been stored on the female's reproductive system. In the British cases, no foreign DNA was encountered.

"Komodo dragons are one of the few species capable of storing sperm," said Don Boyer, curator of reptiles and amphibians at the San Diego Zoo and species survival plan coordinator for Komodo dragons.

The females have been living together at the Sedgwick County Zoo for 15 years, and they are 16 years old now. Both females have been laying eggs since 2000.

"We never had a male dragon at the zoo. There were no tramps that came wandering through," said Nate Nelson, the zoo's curator of amphibians, reptiles and fishes.

One of the two females laid 17 eggs on the nights of May 19 and 20, 2007 (female Komodo dragons can lay up to 30 eggs at a time).

"Because the English zoos had documented parthenogenesis, the Sedgwick County Zoo checked to see whether the eggs were fertile. Only two of the 17 eggs were hatched - one on Jan. 31 and the other Feb. 1 - because the zoo doesn't have room for more dragons," Nelson said.

Both offspring are males: one is 16 inches (40 cm) long; the other is 17 in (42.5 cm). Komodo dragons have a lifespan of up to 40 years. 80 dragons live in 30 North American zoos, but only 6 of those zoos breed the dragons.

There are fewer than 4,000 Komodo dragons in the wild, and they are found on three islands in Lesser Sunda (Indonesia): Komodo, Flores and Rinca.

This species is the largest living lizard: adult males can grow up to 3m (10ft) in length and weigh up to 90kg (200lb), while the female is up to 2.1 m (7 ft), weighing 125 pounds (55 kg). Ancient dragons that lived in Australia till recently were three times larger. To ensure genetic diversity of dragons kept in captivity, perhaps zoos should keep males and females together in order to avoid parthenogenesis.