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Tuesday, July 30, 2013

ScienceDaily: Top Environment News

ScienceDaily: Top Environment News


Two 6,000-year-old 'halls of the dead' unearthed

Posted: 29 Jul 2013 08:14 PM PDT

The remains of two large 6000-year-old halls, each buried within a prehistoric burial mound, have been discovered by archaeologists. The sensational finds on Dorstone Hill, near Peterchurch in Herefordshire, were thought to be constructed between 4000 and 3600 BC.

Monogamy evolved as a mating strategy: New research indicates that social monogamy evolved as a result of competition

Posted: 29 Jul 2013 02:22 PM PDT

Social monogamy, where one breeding female and one breeding male are closely associated with each other over several breeding seasons, appears to have evolved as a mating strategy, new research reveals. It was previously suspected that social monogamy resulted from a need for extra parental care by the father.

Hot flashes? Thank evolution

Posted: 29 Jul 2013 01:19 PM PDT

A study of mortality and fertility patterns among seven species of wild apes and monkeys and their relatives, compared with similar data from hunter-gatherer humans, shows that menopause sets humans apart from other primates.

Social amoebae travel with a posse: Tiny single-celled organisms have amazingly complicated social lives

Posted: 29 Jul 2013 01:17 PM PDT

Some social amoebae farm the bacteria they eat. Now scientists have taken a closer look at one lineage, or clone, of D. discoideum farmer. This farmer carries not one but two strains of bacteria. One strain is the "seed corn" for a crop of edible bacteria, and the other strain is a weapon that produces defensive chemicals. The edible bacteria, the scientists found, evolved from the toxic one.

Study looks beyond averages to track variability in a bacterial population

Posted: 29 Jul 2013 01:17 PM PDT

As a result of the variable nature of gene expression, genetically identical cells inhabiting the same environment can vary significantly in their numbers of key enzymes, which in turn results in strikingly different cellular behaviors. Researchers have captured some of this variability to identify several behavior sub-types in a bacterial population.

Evolution of monogamy in humans the result of infanticide risk, new study suggests

Posted: 29 Jul 2013 01:15 PM PDT

The threat of infants being killed by unrelated males is the key driver of monogamy in humans and other primates, a new study suggests.

Evolution of diverse sex-determining mechanisms in mammals

Posted: 29 Jul 2013 01:15 PM PDT

Researchers have found that a genetic process among the many species of rodents could have significant implications regarding our assumptions about sex determination and the pace of evolution.

Natural affinities -- unrecognized until now -- may have set stage for life to ignite

Posted: 29 Jul 2013 01:15 PM PDT

The chemical components crucial to the start of life on Earth may have primed and protected each other in never-before-realized ways, according to new research. It could mean a simpler scenario for how that first spark of life came about on the planet.

Mini-monsters of the forest floor

Posted: 29 Jul 2013 01:15 PM PDT

A biologist has identified 33 new species of predatory ants in Central America and the Caribbean, and named about a third of the tiny but monstrous-looking insects after ancient Mayan lords and demons.

Hope for tigers lives in Sumatra

Posted: 29 Jul 2013 11:47 AM PDT

Recent findings from a camera trap survey in Sumatra, Indonesia, have uncovered a burgeoning tiger stronghold on an island that typically makes headlines for its rampant loss of forests and wildlife.

Ice-free Arctic winters could explain amplified warming during Pliocene

Posted: 29 Jul 2013 10:35 AM PDT

Year-round ice-free conditions across the surface of the Arctic Ocean could explain why the Earth was substantially warmer during the Pliocene Epoch than it is today, despite similar concentrations of carbon dioxide in the atmosphere, according to new research.

Large Gulf dead zone, but smaller than predicted

Posted: 29 Jul 2013 10:34 AM PDT

Scientists have found a large Gulf of Mexico oxygen-free or hypoxic 'dead' zone, but not as large as had been predicted. Measuring 5,840 square miles, an area the size of Connecticut, the 2013 Gulf dead zone indicates nutrients from the Mississippi River watershed, which drains 40 percent of the lower 48 states, are continuing to affect the nation's commercial and recreational marine resources in the Gulf.

Global warming endangers South American water supply

Posted: 29 Jul 2013 10:31 AM PDT

Chile and Argentina may face critical water storage issues due to rain-bearing westerly winds over South America's Patagonian Ice-Field to moving south as a result of global warming.

Early exposure to insecticides gives amphibians higher tolerance later

Posted: 29 Jul 2013 10:31 AM PDT

Amphibians exposed to insecticides early in life -- even those not yet hatched -- have a higher tolerance to those same insecticides later in life, according to a recent study.

Of bears and berries: Return of wolves aids grizzly bears in Yellowstone

Posted: 29 Jul 2013 10:31 AM PDT

A new study suggests that the return of wolves to Yellowstone National Park is beginning to bring back a key part of the diet of grizzly bears that has been missing for much of the past century -- berries that help bears put on fat before going into hibernation. The berries could aid bear survival and reproduction.

Cells move as concentration shifts

Posted: 29 Jul 2013 10:30 AM PDT

Sheets of biological cells move along the organs they cover by altering the external concentrations of specific molecules. What do wound healing, cancer metastasis, and bacteria colonies have in common? They all involve the collective displacement of biological cells. New research sheds some new light on the physical mechanisms provoking the displacement of a sheet of cell, known as an epithelium. It typically covers our organs including the stomach and intestine, as well as our epidermis. In a new article scientists explain the importance of understanding the displacement of the epithelium as a means of influencing the biological process involved in healing.

X chromosomes: Undoing a hairpin doubles gene activity

Posted: 29 Jul 2013 10:30 AM PDT

Male fruit flies have one X chromosome per cell, females have two. So genes on the male X must work twice as hard to produce the same amount of protein as its female counterparts. Scientists have found a new switch involved in making this possible.

Cockatoos know what's going on behind barriers

Posted: 29 Jul 2013 08:19 AM PDT

How do you know that the cookies are still there even though they have been placed in a cookie jar out-of-sight? Scientists show that "object permanence" abilities in a cockatoo rivals that of apes and four-year-old humans.

Borneo's orangutans are coming down from the trees; Behavior may show adaptation to habitat change

Posted: 29 Jul 2013 05:33 AM PDT

Orangutans might be the king of the swingers, but primatologists in Borneo have found that the great apes spend a surprising amount of time walking on the ground. The research found that it is common for orangutans to come down from the trees to forage or to travel, a discovery which may have implications for conservation efforts.

New whipray species identified by its DNA

Posted: 29 Jul 2013 05:32 AM PDT

Biologists have analysed tissue samples of 115 spotted whiprays of the Himantura genus, collected in various parts of the Indio-Pacific region. By means of genetic markers -- as opposed to morphological criteria only -- the scientists were able to describe these leopard-skin whiprays in detail and demonstrate that they are isolated from each other in terms of reproduction. They have also discovered a new species that they call Himantura tutul, which belongs to a genetic line that is totally distinct from the three other species that are known in the same group: H. leoparda, H. uarnak and H. undulata. They frequent the same costal habitats but occupy different ecological niches.

Tuna and floating objects: Mysterious links

Posted: 29 Jul 2013 05:32 AM PDT

More than 2 000 years ago, Roman fishermen already used the natural propensity of some species of fish to gather under floating objects, to enhance their catches in the Mediterranean. Today, numerous industrial and artisanal tuna fisheries around the world exploit this "aggregating phenomenon." Over the last thirty years, seine fishing in particular has developed rapidly through the use of massive floating objects, natural at first, then more recently fish aggregation devices (abbreviated to FAD) remotely monitored using electronic beacons. Today, these floating objects enable 40% of worldwide tropical tuna catches.

Mystery deepens in coffin-within-a-coffin found at Richard III site

Posted: 28 Jul 2013 07:15 PM PDT

Archaeologists have unearthed a mysterious coffin-within-a-coffin near the final resting place of Richard III.

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