Scientists in China have finished mapping the genome of the giant panda, unlocking secrets about why they eat bamboo and have black circles around their eyes.

Researchers from Cardiff University were part of an international team which undertook the project, using the DNA of a panda from the Chengdu Giant Panda research base.

Wang Jun, a scientist at the Beijing Genomics Institute, said the work should help scientists to understand why pandas have so few cubs.

The results will also aid the development of medicines to control disease in pandas, which are critically endangered. Pandas have roughly the same number of genes, 30,000, as humans.

The team has also found evidence to support the theory that pandas are a subspecies of the black bear, rather than a relative of the raccoon.

"We've laid the genetic and biological foundation for a deeper understanding of this peculiar species," said Dr Wang.

A three-year-old female panda, named Jing Jing, was chosen by scientists for the genome sequencing. Jing Jing was also used as a model by the artists drawing up Beijing's Olympic mascots.

Professor Mike Bruford, at Cardiff's School of Biosciences, said the genome would reveal clues about the history of the panda in "unparalleled detail".

Pandas, or their relatives, are thought to have existed in China for more than eight million years.