Mapping the Genes of the Woolly Mammoth (No Living Example Needed)
Also: An American researcher finds an unusual-looking insect in Brazil. And a warning about letting children have exotic pets. Transcript of radio broadcast: 08 December 2008
VOICE ONE:
This is SCIENCE IN THE NEWS, in VOA Special
English. I'm Bob Doughty.
VOICE TWO:
And
I'm Barbara Klein. This week, we will
tell about a genetic map for an animal that disappeared long ago. We will tell about an unusual-looking insect
from South America. And we will tell
about a reported link between animals and health problems in children.
(MUSIC)
VOICE ONE:
Woolly mammoth
Scientists
say they have completed most of a genetic map for an ancient creature -- the
woolly mammoth. The map is said to be
the first to show the genetic structure of an animal that no longer
exists.
Biologists
at the Pennsylvania State University studied the remains of two woolly mammoths
from Siberia. One mammoth lived twenty
thousand years ago. The other lived at
least sixty thousand years ago.
VOICE TWO:
The woolly mammoth belongs to a species,
or group, linked to the modern African elephant. With its thick, long hair, the now extinct
mammoth was able to survive in cold weather.
Lead researcher Stephan Schuster says the mammoth and African elephant
share more than ninety-nine percent of their genetic material.
STEPHAN SCHUSTER:"So this tells you that they are very, very similar. And also, just because the mammoth is extinct
does not mean it is an ancient elephant.
It is as modern as an Asian or African elephant. But unfortunately, it had the bad luck to go
extinct before today."
VOICE TWO:
Mister Schuster and the research team studied genes, or
DNA, that were found in long pieces of mammoth hair. They say genes from hair are better to study
than those from bones or other remains. That
is because the genes from hair are less likely to mix with other kinds of
DNA.
VOICE ONE:
The
researchers say they were able to uncover about seventy percent of the
mammoth's genome, or genetic structure. They also say the study will help scientists
better understand how elephants evolved, or developed.
Mister
Schuster says the information shows the mammoth evolved from the African
elephant six million years ago. Mammoths
disappeared about ten thousand years ago.
VOICE TWO:
The
researchers hope their work will also increase understanding of how the woolly
mammoth evolved and why it died out.
Their findings were reported in the publication Nature.
The study also provides some information that would be
needed to re-create the mammoth. But scientists
say such an animal would not be possible any time soon -- if ever.
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VOICE ONE:
Some
researchers like to study animals that disappeared long ago. But others want to discover new species --
creatures that may have existed for thousands of years, but remain unknown to
scientists.
One
recent discovery was made in Brazil.
This is where a researcher from the United States discovered a new ant
species. Christian Rabeling is a
graduate student at the University of Texas in Austin. He believes the species could be linked to
some of the earliest kinds of ants to have evolved.
VOICE TWO:
The ant has a very unusual appearance. It is extremely light in color and has no
eyes. It also has large extensions from
its head called mandibles. These are likely
used to capture food.
Because
of its appearance, the ant was given the scientific name Martialis
heureka. The name means "ant from Mars."
The
insect is two to three millimeters long.
Scientists believe its appearance resulted from changes that took place
for the ant to better live under the ground.
VOICE ONE:
Genetic testing shows the ant belongs to a new ant
subfamily. There are twenty-one known ant
subfamilies. The discovery marks the
first time since nineteen twenty-three that a new ant subfamily has been
identified. Since then, new subfamilies
have only been found from fossilized ant remains.
The
genes of the new ant also show that it comes from a species that first evolved
from the wasp. Ants developed from these
insects more than one hundred twenty million years ago. Some species changed to live in trees or in
their leaves.
Scientists believe others like the new species may have
evolved to live in the dirt. That would
explain the ant's loss of eyes and light color.
VOICE TWO:
Christian
Rabeling collected the only example of the new species in two thousand
three. It was found among leaves in the
Amazon rainforest. Mister Rabeling reported
on the discovery in the Proceedings of the National Academy of Sciences. He says finding new ant species could help
scientists understand more about the evolution of ants. He believes many other species have yet to be
discovered in warm climates.
(MUSIC)
VOICE ONE:
Many families in
the United States have at least one pet.
The most popular are dogs, cats and fish. Some Americans own exotic, less traditional
pets. They care for animals like hedgehogs,
monkeys or snakes.
Recently, a report warned that non-traditional
pets may cause serious health problems in children. The report appeared in Pediatrics, a
publication of the American Academy of Pediatrics. It says families with children less than five
years old should not have exotic pets. It
says children that age should avoid contact with such animals in petting zoos,
schools and other public places.
VOICE TWO:
The
report says the number of exotic pets available in the United States has increased
since nineteen ninety two. Many people
find them easier to care for than other pets.
For example, more than four million American homes have reptiles like
snakes and turtles as pets.
Pet hedgehogs can be dangerous for young children.
Another
exotic pet, the hedgehog, is native to Europe, Asia and Africa. But hedgehogs can now be found in forty thousand
homes. Yet the animal also can spread
salmonella infections. The sharp spines
on their back also make it easier to spread infections like E. coli. Exotic pets also can cause allergic reactions
and sicknesses like rabies.
VOICE ONE:
Larry
Pickering was a lead researcher in the study.
He says eleven percent of salmonella infections in children are believed
to be caused by touching lizards or other reptiles. Salmonella can cause the uncontrolled
expulsion of body wastes. It also can
cause high body temperatures and stomach problems.
Children
can become sick by kissing or touching animals and then putting their fingers
in their mouths. Young children are
especially at risk because their natural defenses against disease are still
developing. Also at risk are other
persons with weakened defense systems, older adults and pregnant woman.
VOICE TWO:
The
report says parents need to be educated about the health risks caused by exotic
pets. And, it says, families with
children under the age of five should not own such animals.
It
says parents should first talk with their children's doctors and animal experts
to see if there is cause for concern.
And, it suggests washing hands often to help decrease risks for disease.
(MUSIC)
VOICE ONE:
Bacterial
meningitis must be treated with antibiotic drugs as soon as possible or the
infection can cause hearing loss and brain damage. It can also kill.
A
large area in Africa holds the world record for the most meningitis cases. Known as the meningitis belt, this area extends
from Senegal in the west to Ethiopia in the east. More than two hundred fifty thousand people
got sick there in nineteen ninety-six and nineteen ninety-seven. Twenty-five thousand of them died from
meningitis. The disease still strikes
the area from time to time.
VOICE TWO:
Nations along the
meningitis belt agreed in September to support a campaign to protect their
populations with a new vaccine. The
World Health Organization will provide technical aid with the vaccine.
The
campaign will also get help from weather experts. One partner in the effort is America's
National Center for Atmospheric Research. It will make long-term weather predictions
along the meningitis belt. Local health officials
can then plan the best times to vaccinate people.
VOICE ONE:
The disease often strikes
during dry, dusty weather. One possible
reason is that dust can affect the breathing passages and people may be more
open to infection. Another theory is
that people may stay in their homes more during the dry season, making it
easier to catch meningitis from others. The infections usually stop when the rainy
season begins.
Weather experts will provide fourteen-day forecasts of
atmospheric conditions. The weather
program will start in Ghana next year.
(MUSIC)
VOICE TWO:
This SCIENCE IN THE NEW was written by Lawan Davis,
Jerilyn Watson and Brianna Blake, who was also our producer. I'm Barbara Klein.
VOICE ONE:
And
I'm Bob Doughty. Join us again next week
for more news about science in Special English on the Voice of
America.