This is SCIENCE IN THE NEWS in VOA Special
English. I'm Bob Doughty.
I'm Barbara Klein. This week, we will
tell about mammal populations in danger of disappearing. We will also tell about one kind of animal
that disappeared long ago. And, we will
examine some traditional beliefs about the viruses that cause influenza and the
worldwide study has found that almost twenty-five percent of wild mammals are
in danger of permanently disappearing.
Scientific researchers considered all known mammal populations. The researchers say permanent disappearance
threatens at least one thousand one hundred forty-one species or groups of
animals. Mammals are the closest
relatives to human beings.
researchers are blaming loss of habitat, or living space, and hunting for
threatened land mammals. They say water
mammals suffer more from pollution, being hit by ships and caught in fishing
thousand seven hundred experts worked on the study. They are from one hundred thirty
countries. Their findings were reported
at the World Conservation Conference of the International Union for
Conservation of Nature in Barcelona, Spain.
The report was presented in connection with the Red
List of Threatened Species. The World
Conservation Conference announces the Red List each year. The list contains almost forty five thousand
animals and plants. Of those, almost
seventeen thousand, or about thirty eight percent, are threatened with
scientists say the report provides evidence that Earth's wildlife is going
through widespread extinction. The last
such period may have taken place millions of years ago, when dinosaurs became
Jan Schipper led the writing of the report. He directs the I.U.C.N.'s program that
observes animal populations worldwide.
Schipper says up to thirty six percent of mammals could be facing
extinction. He says this is true because
not much information exists about some species.
At least seventy-six mammals have permanently disappeared since fifteen
director general of the I.U.C.N., Julia Marton-Lefevre, says human activity
could cause loss of hundreds of species.
She says that is a frightening sign of what is happening to
habitats. Still, the report said human
efforts also could help save some species.
Miz Marton-Lefevre is calling for action to make that happen.
study purposes, the I.U.C.N. divides animals into groups. The scientists call animals that have
disappeared, or almost disappeared, extinct or nearly extinct. A frog-like creature called Holdridge's toad
was declared extinct. It lived only in
divisions depend on the amount of threat the animals face. The animals in most danger are considered
example, the Iberian lynx is called critically endangered. As few as eighty-four adult members of the
large, cat-like animals remain alive.
The Red List identifies the second most threatened
animals as endangered. The scientists
named a Southeast Asian animal, the fishing cat, as among the endangered. Part
of the fishing cat's wetland habitat no longer exists.
new study suggests the last woolly mammoths in Siberia were native to North
America. Scientists had believed these
mammoths came from Europe or Asia.
The study involved genetic evidence from the remains of
the ancient animal. Woolly Mammoths
share an ancestor with modern-day elephants.
The mammoth is recognizable for its long hair and large tusks.
disappeared thousands of years ago, after Earth's most recent ice age. But mammoths were able to survive for
thousands of years. During this period,
they slowly changed to live in extremely cold climates.
believe the ancestors of woolly mammoths came from Africa. As the African mammoths moved north to
Eurasia, scientists believe, they grew long hair to protect them from the
extreme cold of Siberia.
better understand these animals, an international research team examined
genetic material from more than one hundred woolly mammoth remains. The remains were found in North America,
Europe and Asia. These fossils came from
woolly mammoths that lived between forty-four thousand and eleven thousand
Hendrik Poinar is
a molecular evolutionary geneticist at McMaster University in Ontario,
Canada. He and his team examined genetic
material from fossilized teeth and pieces of bones from woolly mammoths. They also examined results of earlier woolly
recently, many scientists believed that mammoths came from Europe and Asia
because that is where the oldest fossils were found. Earlier studies of the mammoths involved only
one continent at a time. The researchers
discovered that mammals traveled back and forth several times between Eurasia
and Alaska over thousands of years. The
animals were able to travel on a land bridge that connected Siberia and Alaska
during low sea levels.
researchers discovered that the mammoths were divided in three major
groups. One group lived mainly in
Asia. Another group lived mainly in the
Americas. And, a third group lived in
both places. They believe the American
mammoths traveled back across the Bering Strait and in time replaced the other
populations of mammoths.
The researchers believe the animals moved the
great distances in search of food. A
report with their findings was published in Current Biology. Other researchers disputed the findings. They say the study is based on only limited
Autumn and winter are cold and flu season -- when
people are most likely to catch the viruses that cause influenza and the common
Is the old advice true that wearing warm clothing will
help prevent a cold? Or if you do get
sick, should you follow the old saying, "Feed a cold and starve a
fever"? And what about that fever? Should you take medication to reduce your
temperature, or is it better to let the body treat the infection itself?
seems to have an answer. But how much
value is there in popular wisdom?
Alvin Nelson El Amin knows a lot about cold and flu season. He is medical director of the immunization
program for the Los Angeles County Department of Public Health in California.
Nelson El Amin says studies may be just starting to provide evidence for
long-held beliefs. For example,
scientists for years dismissed the idea that getting cold and wet might cause
colds or flu.
recent studies have shown that cold temperatures cause stress on the body. That stress can create conditions more
inviting to viruses. So maybe it does
make sense to wrap up warmly before leaving home.
And what about the advice to feed a cold and starve a
fever? Doctor Nelson El Amin says you
should eat if you have a cold and are hungry.
But a higher than normal body temperature suggests a more serious
problem. He says people are usually not
hungry anyway when they have a high fever.
Eating might even cause a person to vomit. But drinking plenty of liquids is
important. A fever can easily dehydrate
when should you treat a fever? Doctor
Nelson El Amin says a fever should be treated if it stays at forty degrees
centigrade or above for a day or more. A
temperature that high can damage brain cells.
The doctor also believes in treating a fever if it prevents a person
acetaminophen and ibuprofen can all be used to reduce pain and fever. But aspirin should not be given to children
because it can cause a rare condition.
One belief that Doctor Nelson El Amin wanted to make
clear is wrong is that influenza vaccine can cause the flu. It cannot.
Sometimes people get the flu from another person soon after they get
vaccinated, so they blame the vaccine, he says.
flu vaccines do not protect everyone who gets them. Still, even if a person
does get sick, the vaccine can limit the effects of the virus.
SCIENCE IN THE NEWS was written by Jerilyn Watson, Caty Weaver and Brianna
Blake, who also was our producer. I'm
And I'm Bob Doughty.
Read and listen to our programs at voaspecialenglish.com. Listen again next week for more news about
science, in Special English, on the Voice of America.