The Dirt: This Week in Nature

World’s Largest Cellular Organisms Found In World’s Deepest Ocean.

The Marianas Trench is as deep as Earth’s oceans can get – some
37,000 feet deep. It is also host to the largest singular cell organism found to date. Known as xenophyophores, these oversized cells are like gigantic amoebas and are able to withstand the crushing pressures of the ocean at 6.6 miles below sea level. The cells can be as large as 4 inches. Scientists are still trying to understand how xenophyophores are able to live at these pressures, but their importance for research is in what they can teach us about the limits of life in extreme environments.

Read the full story at Our Amazing Planet.

Genetics May Link Autism to Its Opposite.

“Williams Disease” is characterized by friendliness so extreme that it can startle strangers. In fact, it would appear that children with this disorder have no concept of strangers at all. Typically, these children have “elfin” physical features, low IQ and are extremely verbal and outgoing. Recently, scientists studying the genetics underlying Williams have detected a commonality in deletions in certain gene groups in chromosome number 7. If these genetic alterations are actually linked to Williams, they might provide insight into the genetics underlying autism, a polar opposite disorder, in which social skills, communication and verbalization are severely impaired.

Read the full story at MSNBC.

Future Tissue Transplants May Focus on Pigs.

Long waiting lists for tissue and organ transplant recipients throughout the world have accelerated efforts to use animal tissues and organs for human transplants.
In this article, the authors believe that pigs will turn out to be useful transplant donors for
many types of tissues, from corneas to even the heart. However, these are not just ordinary pigs, but genetically modified ones in which the altered DNA will minimize rejection by the human recipient. Trials with non-human primates already have shown the feasibility of the approach using pig neural cell transplants. The authors conclude that “clinical trials will be justified within the next 2-3 years.”

Another Study Finds That Earth’s Temperature is Rising.

After polling the digital data from 40,000 weather stations worldwide, a group of researchers has concluded that the earth’s temperature is indeed rising. Their finding is in agreement with European and NASA’s previous measurements. Analyzing the weather station data, the researchers found the land temperatures have risen 1.8 degrees Fahrenheit since the 1950’s. The study was intended to address skeptical speculation in online blogs that real measurements from weather stations would not support NASA’s data.

Read the full story at Red Orbit.

Humans and Chimps: The Differences May Be In DNA’s Gaps.

Why humans and chimps are so different despite the very similar nature of their DNA sequencing has remained a mystery. Georgia Tech Professor of Biology, John McDonald has hypothesized that it is not the similarity in the human/chimp DNA genome sequence that is so important, but rather how those nearly identical genes are turned on and off that is critical. What was once called “junk DNA,” the portion of the DNA molecule that appears to be nothing more than endless repeats of the four elements of DNA’s code, may actually influence which genes are activated, which in turn determines whether the animal has human or chimp physical characteristics and behavior.

Read the full story at Red Orbit.

Good Vibrations – Spiders Can Feel Your Presence.

With some 3,000 “strain detectors” built into its body, a spider is one of the most sensitive vibration detectors in the animal world. The spider’s trick is the use of tiny slits in one of its organs that can detect vibrations on the nanoscale level. And spiders don’t need their intricate webs to figure out when lunch is nearby. Even non-web weaving spiders can simply wait for their prey to approach their area; as soon as they detect the particular ground vibration associated with their prey, they spring into action. On the other hand, if a large animal comes by, they can detect the difference in vibrational pattern and stay hidden.

Read the full story at Discovery.

Close Encounter with a Blue Whale.

In this video, a California kayaker comes shoulder to shoulder with a blue whale, which is an endangered sea mammal.

Mastodon Rib Offers Clue to First North Americans.

A rib that belonged to the extinct mastodon — an elephant like creature that roamed North America thousands of years ago — is shedding light on when humans first settled the continent. The rib contains the fragment of a sharpened 10″ bone tip, part of an apparent hunting weapon used by humans to kill the creature. A new carbon-dating technique had provided evidence that the wounded animal was alive around 13,800 years ago. If so, it establishes human presence in North America well before the Clovis people, who previously were presumed to be the earliest settlers.

Read the full story at the New York Times.

In Fits and Starts, Terrestrial Life Rebounded from the Permian Extinction.

The unknown cataclysmic event(s) that wiped out most of the life on earth some 250 million years ago made possible the inhabitants of earth today. Researchers at Brown University together with those at the University of Utah have studied fossils from around the world that date back to before and after the Permian extinction event. The sudden disappearance of so many species led to the disruption of both the marine and terrestrial ecosystems throughout the world. It required millions of years for those ecosystems to re-stabilize. It now appears that the terrestrial experience was similar to what was already known about what happened to life in the oceans — during the stabilization period, species sprung up, flourished and died out, in rapid succession. The study shows the critical importance of a stable ecosystem for all species’ interdependent survival, but also the ability of life eventually to re-establish itself, in some form, once the disruptions have ceased.

Read the full story at Red Orbit.

Bat Die-off Traced to Fungus.

A malady that has killed millions of bats in the United States has now been linked to a fungus. Bats with the illness have white smudges on the snouts, hence the disease is named “white nose syndrome.” The disease is spread by contact between bats and affects animals both healthy and sick. Because there is “no silver bullet” to kill the fungus, and since the use of fungicides in caves carries environmental hazards for other cave dwellers, inoculation of bats may be the best hope for eliminating or controlling the epidemic. Studying the apparent immunity of Europeans bats to an almost identical fungus could be helpful in learning how to construct that vaccine.

Read the full story at New Scientist.