[ born again? ]

The cloning of long-extinct animals such as the thylacine may be beyond the frontiers of science right now, but clones of livestock and, recently, cats are already a reality. Scientists are also working to clone several endangered species--though, of course, cloning is no substitute for habitat preservation--and analyzing ancient DNA to better understand evolution. Here's a roundup of some recent projects.

Gaur

Status: Extremely rare, but no recent population figures; inhabits India and Southeast Asia

Born on January 8, 2001, a gaur named Noah was the first clone of an endangered animal. American scientists created the baby gaur, a species of wild ox, by implanting DNA from the frozen tissue of a deceased male gaur into the eggs of a common cow from which the genetic material had been removed. The cow, acting as a surrogate mother, brought the gaur to term. However, within 48 hours Noah died of dysentery, which scientists say was unrelated to cloning.

Asiatic Cheetah

Status: Fewer than 60 remain, in Iran

Indian scientists plan to reintroduce the cheetah to the Indian subcontinent by means of a clone. The donor DNA will be taken from a captive cheetah and implanted into the eggs of a leopard that have been stripped of genetic material. The leopard will carry the mixed embryo to term. A live birth is hoped for within a few years.

Giant Panda

Status: About 1,000 remain, in southwestern China

Because the panda is a notoriously reluctant breeder in captivity, American biologists are considering cloning preserved cells from Hsing-Hsing and Ling-Ling, two pandas that died in the 1990s at the National Zoo, in Washington, D.C. Black bears would serve as surrogate moms for the born-again pandas.

Pyrenean Ibex (Bucardo)

Status: Extinct, in 2000

The last known member of this Spanish goat subspecies was killed by a falling tree on January 6, 2000. Just months before its demise, Spanish scientists had captured the animal and taken tissue from its ears with an eye toward preserving the species; it is expected to yield DNA that is good enough for cloning.

Moa

Status: Extinct, circa 1500

In 2001 two species of this giant flightless New Zealand bird (of which there were 11 species in all) became the first extinct animals to have their mitochondrial genome sequenced. This achievement by Oxford scientists is critical to the understanding of the evolution, age, and distribution of some modern orders of birds, as well as the effect the moa had on the evolution of New Zealand's plants.

Woolly Mammoth

Status: Extinct on the continents circa 8000 b.c. (2000 b.c. for a small population on Wrangel Island, off Siberia)

When a frozen woolly mammoth was discovered on the steppes of Russia in 1997, it was thought to be more or less intact, and much hullabaloo ensued over resurrecting the species through cloning. But the ancient pachyderm's genetic code turned out to be badly damaged, a jumble of pieces hundreds of times smaller than the DNA used in the Human Genome Project.

--Sydney Horton