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)