Ice Age Horses May Have Been Killed Off by Humans, Study Finds

Some 12,000 years ago, North American mammoths, ancient horses, and many other large mammals vanished within the short span of perhaps 400 years. Scientists cannot be sure what killed them, but a new study suggests that humans aren't off the hook just yet.

The large animals' disappearance at the end of the Pleistocene era (50,000 to 10,000 years ago) happened at about the same time that many large animals, or megafauna, went extinct around the globe.

Victims included species such as the saber-toothed cat and the diprotodon—a rhinolike beast that was the world's largest marsupial.

Now a new study of the fossil record fuels the debate about the cause of the creatures' fate.

In North America two major events occurred at about the same time as the megafaunal extinctions: The planet cooled, and early humans arrived from Asia to populate the continent.

For decades scientists have debated which of these factors was responsible for widespread megafaunal extinctions.

Was the climate change simply too much for the animals to withstand? Or did the ancient mammals succumb to human hunting pressure?

Many experts suggest a combination of these factors and perhaps others, such as disease.

Ice Age Horses May Have Been Killed Off by Humans, Study Finds

Mobile masts signal rain showers

The signals from mobile phone masts have been used to measure rainfall patterns in Israel, scientists report.

A team from the University of Tel-Aviv analysed information routinely collected by mobile networks to make their estimates.

Writing in the journal Science, the researchers say their technique is more accurate than current methods used by meteorological services.

The scientists believe the technique can also measure snowfall, hail or fog.

"It may also be important because if you know there is heavy rainfall - you can warn about floods," Professor Hagit Messer-Yaron, of the University of Tel-Aviv, told the BBC News website.

The team's method exploits the fact that the strength of electromagnetic signals is weakened by certain types of weather and particularly rain.

Mobile masts signal rain showers

Scientists find new species in Atlantic

OSLO (Reuters) - Scientists have found about 10-20 new species of tiny creatures in the depths of the Atlantic in a survey that will gauge whether global warming may harm life in the oceans, an international report said on Thursday.

The survey, of tropical waters between the eastern United States and the mid-Atlantic ridge, used special nets to catch fragile zooplankton -- animals such as shrimp, jellyfish and swimming worms -- at lightless depths of 1-5 km (0.6-3 miles).

"This was a voyage of exploration ... the deepest parts of the oceans are hardly ever sampled," said Peter Wiebe, the cruise's scientific leader and senior scientist at the Woods Hole Oceanographic Institution in the United States.

"We found perhaps 10-20 new species of zooplankton," he said of the 20-day voyage by 28 scientists from 14 nations in April.

Most life, including commercial fish stocks, is in the top 1 km of water, but the scientists said the survey showed a surprising abundance even in the depths. The survey will provide a benchmark to judge future changes to the oceans.

Scientists find new species in Atlantic

Human waste crap for plants

Faeces from healthy humans contains live viruses, most of which are plant viruses that could sicken and deform plants, an international study shows.

The finding, published in the current issue of the journal Polo Biology, could have implications for the use of human waste as fertiliser.

Collected water, otherwise known as reclaimed or grey water, may also contain deadly plant viruses.

But future studies are needed to determine if such water, which is sometimes used for irrigation, can infect plants.

The researchers say the viruses we pass probably do not harm us and airborne transmission is unlikely.

Instead, the viruses probably hitch a ride through the human body via food, even when the food is cooked or dried.

Human waste crap for plants

tornadoes... Nature's most violent windstorm

Although tornadoes occur in many parts of the world, these destructive forces of nature are found most frequently in the United States east of the Rocky Mountains during the spring and summer months. In an average year, 800 tornadoes are reported nationwide, resulting in 80 deaths and over 1,500 injuries. A tornado is defined as a violently rotating column of air extending from a thunderstorm to the ground. The most violent tornadoes are capable of tremendous destruction with wind speeds of 250 mph or more. Damage paths can be in excess of one mile wide and 50 miles long. Once a tornado in Broken Bow, Oklahoma, carried a motel sign 30 miles and dropped it in Arkansas!

Thunderstorms develop in warm, moist air in advance of eastward-moving cold fronts. These thunderstorms often produce large hail, strong winds, and tornadoes. Tornadoes in the winter and early spring are often associated with strong, frontal systems that form in the Central States and move east. Occasionally, large outbreaks of tornadoes occur with this type of weather pattern. Several states may be affected by numerous severe thunderstorms and tornadoes.

During the spring in the Central Plains, thunderstorms frequently develop along a "dryline," which separates very warm, moist air to the east from hot, dry air to the west. Tornado-producing thunderstorms may form as the dryline moves east during the afternoon hours.

Along the front range of the Rocky Mountains, in the Texas panhandle, and in the southern High Plains, thunderstorms frequently form as air near the ground flows "upslope" toward higher terrain. If other favorable conditions exist, these thunderstorms can produce tornadoes.

Tornadoes occasionally accompany tropical storms and hurricanes that move over land. Tornadoes are most common to the right and ahead of the path of the storm center as it comes onshore.

tornadoes... Nature's most violent windstorm