Inbreeding won't lead to population degeneration? Chinese zoologists and geneticists find it hard to explain how David's deer, known as Milu deer among Chinese, that once extinct in China can restore their population in captivity again without retrogression after generations of inbreeding.
Scientific research shows that after about a dozen years of inbreeding, the species are still on a very healthy track of reproduction without any signs of population retrogression at Tian'ezhou Milu National Nature Reserve in Hubei Province, central China.
The nature reserve introduced 64 David's deer in 1993 and 1994, and the population has grown to 450 today, increasing at an annual rate of 30 percent, said Director Wen Huajun.
"We are quite surprised at how excellent the population quality remains for generations because all the existent Milu deer living in the world are the descendants of the world's last 10 head with reproduction capability," he said.
According to common understanding, population degradation is usually inevitable after so many generations of inbreeding. But the adult Milu deer living in the nature reserve are each 200 to 250 kilograms in weight and look strong with lustrous and sleek fur.
"The fierce competition among male deer for mating might be the answer to the species' population improvement," said Wen.
However, other researchers contend that a DNA test among the surviving Milu groups is needed to discover the real cause behind this genetic miracle.
Gui Jianfang, a researcher and geneticist with Aquatic Biology Research Institute of the Chinese Academy of Sciences, said the maintenance of good population quality might be attributed to their common ancestors, the world's last 10 Milu collected by Herbrand Russell, the 11th Duke of Bedford, between late 19th century and early 20th century.
"Those 10 Milu deer might concentrate the species' most excellent genes, but further genetic research is needed to explain this scientific mystery," Gui said.
Native to China, Milu deer earn themselves an odd nickname of "none of the four" which refers to the striking features in their appearance -- a camel's neck, a donkey's tail, cow-like hooves and stag's horn.
The species was named Pere David's deer after Pere David, a Basque missionary, became the first Westerner to introduce the strange beast to Europe in late 19th century.
Milu was once extinct in their native habitat in China in late 19th century due to flooding, hunting and wars.
Yet the exotic deer were able to survive in one place -- Bedfordshire, England -- due to the nurturing of a devoted caretaker, the 11th Duke of Bedford, who kept the world's last 18 herd at Woburn Abbey. This labor and persistence paid off nearly a century later, and in 1985, 22 of the British herd were returned to China.
Besides the nature reserve in Hubei, Milu deer are also raised in some other parts of China now, including Beijing, Dafeng City in Jiangsu and Yuanyang County Henan, with a total population of more than 2,000.
China has released 32 Milu deer to marshy areas since 1998 to see whether the species could still regain their ability to survive in the wild. In 1999, a cub was born in the wild, which gave birth to one baby in March 2003.
(Xinua News Agency April 11, 2004)
