Chimp Ancestors Made Pals 6 Million Years Ago

BFF's among primates date back to 6 million years ago, with friends that picked each other, literally.

Friendship as we know it today -- complete with BFF’s, trusted pals and more -- emerged in Africa 6 million years ago in the last common ancestor of chimpanzees and humans, a new Evolution & Human Behavior study suggests.

This clever primate literally figured out that “I’ll scratch your back if you scratch mine” makes life a lot easier.

“We know that it must have been a group-living species with relatively developed cognitive skills,” co-author Sonja Koski of the University of Zurich told Discovery News. “For example, it knew how to make and use simple tools and it understood some aspects of what other individuals are thinking. It also learned most of its necessary survival skills and knowledge socially, giving rise to the possibility of cultural differences in behavior between populations.”

“The groups consisted of many males and females, and individuals formed cooperative friendships,” she added. “Our results suggest that the preference to form these friendships with individuals much like oneself was present in the ancestor of chimpanzees and humans.”

Koski and co-author Jorg Massen of the University of Vienna found that chimpanzee buddies are remarkably similar to human friends. Both need emotionally rewarding, positive interactions with others, and these connections result in durable and mutually beneficial bonds. Chimp friendships, like human ones, can last for a very long time.

The researchers first investigated the personality similarity of friends among 38 captive chimpanzees. They determined that chimps were more likely to be friends if they possessed similar tendencies for sociability and boldness.

Sociability basically refers to how gregarious the individual is. In chimps, this is evident in grooming behaviors.

“So, highly sociable individuals hang out with others and groom them more often, while less sociable individuals are more aloof and do not groom much,” Koski explained.

She and Massen presented chimps with a stuffed leopard and an artificial snake to test boldness.

“The bold individuals approached these ‘predators’ quickly and aggressively, while the shy individuals stayed back,” she said.

Earlier research found that humans also tend to select buddies who have similar levels of friendliness and assertiveness. Traits like neuroticism, which refers to the general tendency to respond with stress and anxiety to situations, do not lead to bonding, so a more neurotic human or chimp is not likely to connect with a similarly neurotic individual.

There could be a genetic component to friendship, given that primates appear to be born more or less social and bold, with those qualities reinforced -- or not -- via environment, upbringing and experiences.

Anthropologist Joan Silk of the University of California at Los Angeles has also studied social interactions among primates. She said the new paper presents “very interesting results.”

“In our own work on baboons, we have found that certain pairs of females form social bonds that are characterized by high levels of friendly interactions and well-balanced grooming relationships; high ratios of friendly to aggressive interactions; and higher levels of support in agonistic conflicts,” Silk told Discovery News.

“Pairs that form the strongest relationships also have the most enduring relationships over time,” she continued, adding that baboons with the closest, longest-lasting friendly interactions display lowered stress levels.

Read more at Discovery News

Scene of 1,500-Year-Old Massacre Uncovered in Sweden

At the site of an ancient island fort in Sweden, archaeologists have uncovered the victims of a sudden massacre, whose bodies were frozen in time for centuries much like the victims of Pompeii.

Researchers think hundreds of people once lived in single-family stone houses within the walled settlement on Öland, a long narrow island off the southeast coast of Sweden in the Baltic Sea. But the fifth-century fort seems to have been left in ruins after an ambush, recent excavations suggest.

"I don't think anyone dared to go near it for a very long time," Helene Wilhelmson, an osteologist at Lund University said in a video released by the school.

"It's more of a frozen moment than you normally see in archaeology," Wilhelmson added. "It's like Pompeii. Something terrible happened and everything just stopped."

In an initial investigation at the site in 2010, researchers found jewelry boxes with finely-crafted gilded broaches and sets of beads, hinting at former occupation. Later, researchers found traces of a house within the fort. In the doorway, they uncovered two feet peeking out, Wilhelmson said.

The archaeologists eventually excavated the full skeleton, which had signs of blunt force trauma to the head and shoulder. So far the researchers say they have found five sets of human remains, all belonging to people who seem to have met a sudden death.

"I think they were surprised," Wilhelmson said, explaining that two of bodies were found lying close to each other by the door as if they were running out to escape when they were killed. The arrangement of the dead bodies is especially unusual for a period when people in the region traditionally burned their dead on a funeral pyre.

The archaeologists are using 3D modeling to reconstruct the 1,500-year-old crime scene. The technique will give them a chance to see, simultaneously, all the bodies where they fell even though archaeologists have removed the skeletons one by one.

"We never have the complete scene exposed at the same moment, but using the 3D models we can actually recreate the complete scene," Lund University archaeologist Nicolo Dell'Unto said in a video.

Read more at Discovery News

Human Ancestors' Oral Hygiene: The Toothpick

Overuse of toothpicks might be one reason that explains the mystery of why the jaws of the oldest-known extinct human relatives found outside Africa could vary so much, researchers say.

These findings suggest tool use could have helped to alter drastically how these ancient members of the human family tree ate and survived. In addition, the evidence suggests human ancestors may have overused the toothpick in some instances, possibly leading to swelling and infection.

The origin of the human family tree is rooted in Africa. The earliest known remains of hominids -- humans and all their extinct relatives after they split from the ancestors of chimpanzees -- that researchers have unearthed yet outside of Africa are nearly 1.8-million-year-old fossils discovered at the site of Dmanisi in the Republic of Georgia.

The remains of several hominids were previously discovered at Dmanisi, which ranged from adolescence to old age. Included within these fossils were four lower jaws, or mandibles.

"Fossil findings in human evolution are often represented by mandibles, because typically they are better preserved than any other parts of the skeleton except teeth during fossilization processes," said researcher Ann Margvelashvili, a paleoanthropologist at the University of Zurich's Anthropological Institute and Museum in Switzerland.

Mysteriously, these jaws varied widely in shape from each other, more than scientists could satisfactorily explain up to now. Some researchers suggested the discrepancies might reflect ones between the sexes within a species; others proposed they represented disparities between different species.

To help solve this puzzle, scientists analyzed how jawbones from modern hunter-gatherers from Australia and Greenland could vary and compared them with Dmanisi teeth and jaws. They relied on X-rays and microscopic analysis of these samples, focusing on the wear on teeth and the resulting changes in jawbones.

Based on their data, the researchers suggest the amount of variation seen in the Dmanisi jaws reflects the differences one might normally expect within a species. Tooth wear could, in theory, greatly augment differences between individuals by reshaping features of jawbones, such as how the rows of teeth are shaped and the height and angle of the jaws.

"Researchers should always be attentive with the details when dealing with teeth, because those details often reveal many secrets of behavior, which are not visible at first to the eye," Margvelashvili told LiveScience.

In addition, scratches on the root of a tooth in one jawbone suggested repeated toothpicking caused inflammation there.

"Dmanisi hominids show the first clear case of overusing the toothpick, which led to infection," Margvelashvili said. "The shape of the lesion reflects the shape of the toothpick."

Read more at Discovery News

Fetuses in Womb Explore Their Own Bodies

Humans — while still fetuses in the womb — explore their bodies as part of their development and even learn how to anticipate touch, according to new research.

High tech 4-dimensional scanning made the discovery possible. The findings are published in the journal Developmental Psychobiology.

“What we have observed are sequential events, which show maturation in the development of fetuses, which is the basis for life after birth,” lead author Nadja Reissland, of the Department of Psychology at Durham University, said in a press release. “The findings could provide more information about when babies are ready to engage with their environment, especially if born prematurely.”

Reissland and her team conducted a total of 60 scans of 15 healthy fetuses at monthly intervals between 24-36 weeks of gestation.

During the earlier part of that developmental period, fetuses frequently touched the upper part and sides of their heads.

As time went on, the fetuses began to increasingly touch the lower, more sensitive, part of their faces, including their mouths.

At 36 weeks of gestation, a significantly higher proportion of fetuses were observed opening their mouths before touching them. This suggests, according to the researchers, that later in pregnancy the fetuses were able to anticipate that their hands were about to touch their mouths, rather than reacting to the touch of their hands.

“Increased touching of the lower part of the face and mouth in fetuses could be an indicator of brain development necessary for healthy development, including preparedness for social interaction, self-soothing and feeding,” Reissland explained.

This is also likely the origin of thumb or finger sucking, done to promote calmness.

The sequence of events appears to have been programmed into us, via genetics, as part of the growth process.

As co-author Brian Francis, Professor of Social Statistics at Lancaster, said: “This effect is likely to be evolutionarily determined, preparing the child for life outside the womb.”

He continued, “Building on these findings, future research could lead to more understanding about how the child is prepared prenatally for life, including their ability to engage with their social environment, regulate stimulation and being ready to take a breast or bottle.”

Read more at Discovery News

This Prehistoric Elephant Had a Huge Spork for a Mouth

Russian writer Anton Chekhov insisted that everything irrelevant to a work of fiction be removed — if you describe a rifle mounted on the wall, someone had better fire it off at some point. This dramatic principle is called Chekhov’s gun, and it actually applies quite well to the natural world: Animals don’t waste energy developing worthless characteristics. Traits that help a species survive get passed along through generations, while those that are no longer useful fade away (or in the stubbornly contrary case of the human appendix, abruptly explode).

If Chekhov had time-traveled back between 8 million and 20 million years and met Platybelodon — an ancestor of the modern elephant that looked like it got hit in the face with a shovel, then absorbed that shovel into its mouth — he would have demanded the creature explain itself. What possible purpose could such a ridiculous trait serve? “A good one, thank you very much,” Platybelodon would reply, probably in a really funny voice.

The spork-faced Platybelodon’s strange jutting jaw actually consists of a second pair of flattened, widened tusks (tusks themselves being modified incisors). When the genus Platybelodon, which means “flat tooth,” and its species were first described in the 1920s, “their lower incisors were thought to function to shovel, scoop, dig and dredge soft vegetation in aquatic or swampy environments,” vertebrate paleontologist William Sanders of the University of Michigan wrote in an email to WIRED. “But recent analysis of tusk wear surfaces show that they were used more as scythes to cut tough vegetation.”

The paleontologist who proposed this slicing behavior in 1992, David Lambert, theorized that instead of roaming shorelines, Platybelodon fed on terrestrial plants, grasping branches with its trunk and cutting them away with its built-in scythe. Indeed, cross-sections of the tusks reveal a structure that provides extra strength and resistance to abrasion for such foraging, said Sanders.

So it could well be that Platybelodon wandered around Miocene Asia, Africa, and North America, scything vegetation like some sort of peasant, only without all the pesky class struggles. And it was just one of a horde of similar animals in the family Gomphotheriidae, all with modified lower tusks of varying styles. The Platybelodon genus alone had more than 15 species, reaching “the apex of development of these lower tusks,” according to Sanders. Their radically flattened teeth suggest “strong selection for specialized feeding on a particular range of plants,” which was crucial given that “for much of the Miocene there were often three to five or more genera of proboscideans occurring in the same landscape, competing for forage.”

Pegging the various appearances of such proboscideans, though, is difficult, because flesh-like schnozes don’t fossilize as easily as bone. We’re actually quite lucky to have Platybelodon preserved at all, considering that fossilization is a really hard thing to pull off. Even if you can avoid getting carted off in a dozen different directions by scavengers, you need to settle in the right spot. And Platybelodon just so happened to do us a solid by dying — sometimes en masse — next to or in rivers, the prime locales for fossilization.

Henry Fairfield Osborn, a paleontologist who described Platybelodon in a 1932 paper and quite extensively four years later in his book Proboscidea, accordingly assumed the creature to be a water-dredger (thanks to the work of Lambert and others we now believe that Platybelodon, like a lot of animals, was probably just partial to water and happened to sometimes die in it). In his book, Osborn quoted another paleontologist, Alexei Borissiak, who in 1929 wrote that Platybelodon was “deprived of a trunk” but would scoop through the water and “seize its food with its muscular upper lip, covering the mandible.” In fact, Borissiak reckoned Platybelodon’s snout looked a bit like that of the hippopotamus, “although much more lengthened out.” Osborn’s illustrations of Platybelodon certainly reflect this.

But “think about what an elephant looks like,” Sanders asks us. “The trunk is a very separate entity from the mouth. You have to be able to get food into your mouth, and if your front limbs are occupied in posture, and you have upper and lower tusks that would make it difficult to have a long projecting tongue or mobile lips, then you need a proboscis.”

Read more at Wired Science

Shutdown Stops T. Rex Trek in Its Tracks

The ongoing government shutdown has stalled plans to haul a near-complete T. rex fossil to its new home at the Smithsonian National Museum of Natural History, a federal institution forced to shut its doors last week.

The T. rex was set to leave its current home in Montana on Friday (Oct. 11) for a cross-country road trip. As part of a new loan agreement, the Smithsonian, the world's most visited natural history museum, will be the dinosaur's steward for the next 50 years.

But Smithsonian magazine, the official journal of the institution, reported that the T. rex transfer has now been postponed until April.

"It's a major specimen, so we're being very prudent about how we handle it," Kirk Johnson, the museum's director, told Smithsonian magazine. "There's a lot of uncertainty with the shutdown, and uncertain availability of federal workers to do the work that we need to do."

The fossil's planned arrival at the Smithsonian on Oct. 16 was meant to coincide with the fourth annual National Fossil Day. The museum typically receives 7.3 million visitors per year, according to its website. It is closed in the wake of the shutdown, and most of its staff has been furloughed.

The dinosaur has been dubbed the Wankel T. rex after Kathy Wankel, a rancher and amateur fossil hunter who discovered its arm bones in Montana's Fort Peck reservoir in 1988. Since it was unearthed on federal lands, the dinosaur belongs to the U.S. Army Corps of Engineers. That agency had loaned the fossil to the Museum of the Rockies at Montana State University in Bozeman, where it was prepared and put on display in its original "death pose" for two decades.

The T. rex, which measures 38 feet (11.5 meters) long and weighs 7 tons (6.3 tonnes), will be the centerpiece of the Smithsonian's new dinosaur hall, scheduled to open in 2019. The new wing will feature other key specimens from the Smithsonian's collection of 46 million fossils.

Read more at Discovery News

Butchering Circa 10,000 B.C.

Big-game hunts about 12,000 years ago involved feasting on a meaty morsel popular with today’s gourmets, followed by chopping, hauling, bone tossing, jewelry making and boasting.

All of these activities are suggested by remains found at a prehistoric Danish butchering site, called Lundy Mose, which is described in a paper accepted for publication in the Journal of Archaeological Science.

Bone fragments belonging to wild boar, red deer and aurochs were unearthed. But the hunters clearly had a taste for elk meat, since elk remains were prevalent at the site, located in South Zealand, Denmark.

“Due to very good conditions of bone preservation, Lundby Mose offers exceptional opportunities for detailed reconstruction of exploitation patterns, and allows a very precise picture of the different activities involved in elk exploitation,” archaeologist Charlotte Leduc of the University of Paris wrote.

Her detailed analysis of the remains determined that the hunters first cut around the elk heads and other parts of the body in order to remove the hides. At least one of the hides then likely became a perishable container, comparable to a garbage bag, upon which refuse was placed and later bundled.

The hunters then removed meat from easy-to-access parts, such as the limbs, and likely feasted on it right then and there. No roasting pit or evidence for fire is mentioned, so it might have been consumed raw.

All skeletal parts containing marrow -- now a delicacy in many fine restaurants -- were fractured to enable its extraction.

Wietske Prummel of the University of Groningen, who analyzed another prehistoric Northern European butchering site, told Discovery News that marrow was usually “consumed by hunters immediately after butchering. It was their reward for the successful kill.”

The hunters skillfully cut around the body, trimming fat and boning meat for later easy consumption. Leduc thinks much of the meat could have been transported to a nearby settlement site.

Before that happened, however, the hunters removed select bones, such as from the long limbs, likely for making bone weapons and tools. They also removed the antlers.

The elk's shoulder blade bones were taken out and afterwards, back at the settlement, “were sometimes worked and used presumably as knives for fish processing,” Leduc suspects.

As the hunters worked, they appear to have dumped waste material onto the reserved hide. It was later tossed into a nearby lake.

The front teeth of the elks were missing, suggesting “a specific status of front teeth for the hunters,” according to Leduc. Other prehistoric hunt scenes support this theory, as do discoveries of prehistoric tooth bling.

This series of events likely played out countless times, even long before 12,000 years ago.

“Modern humans hunted and butchered large game and cooked the meat from circa 45,000 years ago when they arrived in Europe," Marcel Niekus of the University of Groningen, told Discovery News.

Read more at Discovery News

Pluto's 'Thick' Air Isn't Going Anywhere

When astronomers were selling the idea of a NASA mission to Pluto, they added a sense of urgency.  No, they didn’t want to scout out Pluto as an outpost for setting up an early warning system in case of an alien invasion; planetary scientists warned that if we don’t visit the far-flung planet soon, the Pluonian atmosphere will freeze out and collapse onto the surface as fresh nitrogen-methane snow.

This was predicted because the distant world was passing its summer season and heading out billions of miles farther from the sun along a highly elliptical orbit. The warning worked. Launched in 2006, NASA’s New Horizons probe is now sprinting toward a 2015 rendezvous with Pluto as the fastest manmade object ever built.

But don’t worry if the long distance runner doesn’t get there soon enough.  New observations by Catherine Olkin of the Southwest Research Institute in Boulder, Colo., predict that the tenuous nitrogen-methane-carbon monoxide atmosphere will remain buoyant year ’round. In fact, as Pluto enters late summer, the atmosphere is now three times denser than when first measured in 1988. That means it isn’t going anywhere.

These results provide insights into the nature of Pluto’s surface crust, say the researchers. To explain the atmospheric changes there must be a rock-hard water-ice surface that apparently soaks up feeble sunlight and holds onto the heat it for a long time.

Some astronomers have previously dismissed Pluto as an oversized comet nucleus. A comet forms a temporary atmosphere, called a coma, when it is close enough to the sun for surface ices to warm and sublimate. Some scientists called Pluto’s atmosphere just a giant and temporary coma. But comets have frothy surfaces that lose heat quickly and Pluto doesn’t according to the researchers.

We’ve never had an opportunity to observe what really happens during winter on Pluto because it was springtime on the icy world when it was discovered in 1930. Pluto’s summer happened in the late 1980s when it swung inside Neptune’s orbit.

Because of its sluggish 248-year orbit, Pluto won’t be deep into winter until the year 2130. (Astronomers won’t be able to celebrate Pluto’s completion on one orbit since its discovery until the year 2178! Imagine what Earth history will have transpired by then.)

The tilt of Earth’s axis drives seasonal changes on our surface. But in Pluto’s case, seasons are driven by its highly elliptical orbit. Pluto shuttles between distances of 2.7 and 4.6 billion miles from the sun. In winter it is at the outer rim of the Kupier belt’s icy debris that encircles the sun. The consequences are that Pluto receives roughly 30 percent as much sunlight during the long winter than during the comparatively brief summer.

The team looked at Pluto observations taken from 1988 to 2003. These were occultation events where Pluto passes in front of a background star and astronomers can measure the light filtered through Pluto’s atmosphere. This allows for precise measurement of atmospheric pressure.  The team made observations this year to show the atmosphere is thicker than ever before measured.  Still, the anemic atmosphere is just one one-hundred-thousandth the surface pressure of Earth’s atmosphere.

Read more at Discovery News

Cave Reveals Ancient Birds' Eye View

The fossil remains of birds found in a cave in the desolate Nullarbor Plain suggest it was a very different place hundreds of thousands of years ago.

The Thylacoleo Caves, 100 kilometers north-west of Eucla in Western Australia, were named after the ancient Pleistocene marsupial "lion"(Thylacoleo carnifex), which was found in the cave.

Most research in the cave has focused on describing the diverse marsupial fauna, including giant kangaroos (procoptodon) and giant wombats (phascolonus).

But avian palaeontologist Elen Shute, a Ph.D. candidate at Flinders University in Adelaide, has turned her attention to describing the diverse range of birds that have been found trapped in the layers of dirt on the cave floor.

She presents her research today at the 14th biennial Conference on Australasian Vertebrate Evolution, Palaeontology & Systematics.

"It's turning out to be a very diverse site in comparison to other Australian Pleistocene cave fossil deposits," said Shute.

Shute, under the supervision of Dr Gavin Prideaux and Dr Trevor Worthy from the University of Adelaide, has identified more than 40 bird species from the cave site.

"It includes pigeons, birds of prey, a lot of parrots and buttonquails. Interestingly there are three types of megapodes, sometimes called mound builders, including a giant malleefowl."

There are also the remains of several duck species suggesting lakes may have formed part of the environment during the Pleistocene -- a stark contrast to the dry plains and saltbushes that make up the Nullarbor today.

Shute said the diverse range of bird species helps paint a clearer picture of past conditions.

"If you're able to determine a large number of species from a cave deposit you can use overlaps in habitat preferences to draw conclusions about the environment," she explained.

According to Shute, the most exciting discoveries, which are yet to be formally described, are birds that appear to resemble coucals and logrunners.

Today, coucals are found in the tropics and subtropics of northern and eastern Australia, while the logrunner tramps around the rainforests of northern Australia and Papua New Guinea -- more than 4000 kilometers away.

"So we're probably looking at the persistence of thick vegetation [in the Nullarbor], at least at certain times, in the recent past," she said.

Read more at Discovery News

Moon Dances with Three Planets on Sunday, Tuesday

The moon will meet up with three different planets in the evening sky during two upcoming celestial encounters, one on Sunday (Oct. 6) and the other on Tuesday (Oct. 8).

The ringed planet Saturn, sinking into the west-southwest twilight, is close to Mercury in early October. About 40 minutes after sunset on Sunday, try catching a glimpse of Saturn hovering about 5 degrees above a razor-thin sliver of a crescent moon that's just two days past new phase and a mere 4 percent illuminated by the sun.

Brighter Mercury will be situated about 2.5 degrees to the moon's lower left. Your clenched fist held at arm’s length measures roughly 10 degrees, so Saturn and the moon will be separated by half a fist. And the separation between Mercury and the moon will be half of that.

This will be a challenging observation, because all three celestial objects will be very low and possibly dimmed by haze, which is seemingly always thickest down near the horizon. In addition, the background sky will still be quite bright. (Binoculars will be a great help.)

You might have a better chance of seeing this trio if you live in the southern United States, for all three will appear somewhat higher from there as opposed to the view from the northern U.S. or southern Canada. This will probably be your last chance to see Saturn in the evening sky before it transitions into the morning sky early next month.

Better on Tuesday

Two nights later will be a different story. On Tuesday evening, the moon will be about three times higher and more than four times wider (18 percent illuminated), making it a much more obvious target to see with both binoculars and your naked eye.

And its companion will be the brightest of all planets, Venus. This dazzling evening star, shining with a radiance 48 times brighter than Mercury and 85 times that of Saturn, will be readily visible hovering about 7 degrees below and slightly to the right of the moon. In spite of the rather wide gap separating them, both will make for an eye-catching sight in the southwestern sky.

Glittering Venus flames into view soon after sunset. Ever since late last spring it has remained at about the same low altitude in the dusk (for viewers at mid-northern latitudes); it’s hardly any higher after sunset than it has been since June, but three factors are improving its visibility nonetheless:

It is growing a little brighter as it rounds the sun and speeds toward Earth;

Twilight fades faster in the fall than in summer, leaving Venus to shine in a darker sky;

It has shifted from the west to the southwest. Objects at a given altitude above the horizon in the southern part of the sky take longer to set than objects at the same altitude due west.

Venus is also finally climbing higher during October, and it now stays above the horizon until twilight is long over. The planet will be at its highest (and best position for viewing) in late November and early December.

Getting better in telescopes

Behind Venus, Antares and the other stars of Scorpius, a "summer" constellation, slide westward during October on their way out for the year.

On the evening of Oct. 16, look for the 1st-magnitude star Antares -- the Heart of the Scorpion -- shining south (to the lower left) of Venus by just 1.5 degrees; that’s about a finger’s width at arm’s length. Antares twinkles with a distinct reddish hue and is less than 1 percent as bright as Venus.

Telescopically, Venus is becoming a more interesting sight as it draws nearer to Earth and becomes less gibbous. Watch it change in phase from two-thirds illuminated now to half-lit around the end of the month.

Read more at Discovery News