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The First Animal On Earth Was Significantly More Complex Than Previously Believed

A new study mapping the evolutionary history of animals indicates that Earth's first animal -- a mysterious creature whose characteristics can only be inferred from fossils and studies of living animals--was probably significantly more complex than previously believed.

Using new high-powered technologies for analyzing massive volumes of genetic data, the study defined the earliest splits at the base of the animal tree of life. The tree of life is a hierarchical representation of the evolutionary relationships between species that was introduced by Charles Darwin.

Comb jelly
©Casey Dunn
A comb jelly. The evolutionary history of the comb jelly has revealed surprising clues about Earth's first animal.

The study is published in the April 10, 2008 issue of Nature.


Phoenix

'This thing is nuts': The Triassic Pterosaur Raeticodactylus

There are a few fundamental biases in the fossil record and they can heavily influence what you are looking for. The older something is, the less likely you are to find it - every million years older it gets is another million years for it to be subducted, buried, eroded or destroyed. The smaller something is, the harder it is to find - 50 metre sauropods leave behind big bones that can be seen on the surface from half a mile away, rodent teeth are another matter. The more delicate something is, the rarer it is - it is more vulnerable to destruction before and after fossilisation, and even if you find it, it might be so badly crushed that all the details are lost. Finally, the rarer something was in life, the less likely you are to find it - a species with billions of individuals is more likely to enter the fossil record than one with a few hundred.

Raeticodactylus filisurensis
©Rico Stecher
Raeticodactylus filisurensis

Bizarro Earth

Ocean mud yields secrets of past Earth impacts



Asteroid Impact Ocean
©CDW/NSF
Most asteroid impacts on Earth have left few persistent signs, but they may still be detectable in ocean sediment records.

Comment: Read our Special Report series: Comets and Catastrophe


Info

When Genetics And Geology Meet In Patagonia

When Charles Darwin first set foot on Patagonia, he was a fresh-faced 22-year old yet to finesse his revolutionary theory of evolution by natural selection. But traveling around the tip of South America aboard the HMS Beagle-part of an epic, five-year scientific expedition-the young naturalist had his eyes opened to the immense diversity of species and landscapes.

Now, almost two centuries later, a group of scientists from across disciplines and academic institutions in North and South America are revisiting places Darwin explored, and, like him, pondering the connections between the evolution of landscape and of organisms.

Charles Darwin
©Unknown
Charles Darwin

Telescope

Why is the universe's brightest blast still blazing?



Hubble image
©NASA/ESA/N Tanvir/U of Leicester/A Fruchter/STScI
The afterglow of the most powerful explosion ever recorded is shown in this Hubble Space Telescope image. A few galaxies are also visible, but not the host galaxy for the explosion

The most powerful explosion ever observed may have been even more powerful than first thought. Nearly three weeks after the bright 'gamma-ray burst' occurred, it is still outshining its host galaxy, dumbfounding astronomers with its amazing longevity.

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What Happened at Meteor Crater?

Scientists have discovered why there isn't much impact-melted rock at Meteor Crater in northern Arizona.The iron meteorite that blasted out Meteor Crater almost 50,000 years ago was traveling much slower than has been assumed, University of Arizona Regents' Professor H. Jay Melosh and Gareth Collins of the Imperial College London report in the cover article of Nature.

"Meteor Crater was the first terrestrial crater identified as a meteorite impact scar, and it's probably the most studied impact crater on Earth," Melosh said. "We were astonished to discover something entirely unexpected about how it formed."

Meteor crater
©Jim Hurley
Meteor Crater, Arizona

Previous research supposed that the meteorite hit the surface at a velocity between about 34,000 mph and 44,000 mph (15 km/sec and 20 km/sec).

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Underwater Microscope Helps Prevent Shellfish Poisoning Along Gulf Coast of Texas

Through the use of an automated, underwater cell analyzer developed at the Woods Hole Oceanographic Institution (WHOI), researchers and coastal managers were recently able to detect a bloom of harmful marine algae in the Gulf of Mexico and prevent human consumption of tainted shellfish.

Arrow Down

Geologists Discover New Way of Estimating Size and Frequency of Meteorite Impacts

Scientists have developed a new way of determining the size and frequency of meteorites that have collided with Earth.

Their work shows that the size of the meteorite that likely plummeted to Earth at the time of the Cretaceous-Tertiary (K-T) boundary 65 million years ago was four to six kilometers in diameter. The meteorite was the trigger, scientists believe, for the mass extinction of dinosaurs and other life forms.

François Paquay, a geologist at the University of Hawaii at Manoa (UHM), used variations (isotopes) of the rare element osmium in sediments at the ocean bottom to estimate the size of these meteorites. The results are published in this week's issue of the journal Science.

Eye 1

Powerful new satellite to debut over Pacific

The United States is set to start operating a powerful new military communications satellite over the Pacific next week, the first of a planned six-satellite network that will boost data flows 10-fold, the Air Force Space Command said Thursday.

On its own, the maiden Boeing Co-built Wideband Global Satellite will provide more capacity for video, data and voice than the entire group of 10 or so satellites it is designed to replace, the command said.

"We expect to start cutting over operational communications networks from the existing constellation to the new satellite next week," said Air Force Col. James Wolf, chief of the command's military satellite communications division.

Australia joined the WGS program last year, providing funds that expanded it to include the sixth satellite, which had been an option under a contract awarded to Boeing in January 2001.

Rocket

How Rocket Engines Can Be Destroyed By Mysterious Sound Waves



rocket sound waves
©Georgia Institute of Technology
An image of destructive acoustic waves building inside a small, simulated rocket combustor.

There's a strange wave phenomenon that's plagued rocket scientists for years, a lurking threat with the power to destroy an engine at almost any time. For decades, scientists have had a limited understanding of how or why it happens because they could not replicate or investigate the problem under controlled laboratory conditions.