Scientists find 'oldest human ancestor'

Researchers have discovered the earliest known ancestor of humans - along with a vast range of other species.

They say that fossilised traces of the 540-million-year-old creature are "exquisitely well preserved".

The microscopic sea animal is the earliest known step on the evolutionary path that led to fish and - eventually - to humans.

Details of the discovery from central China appear in Nature journal.

The research team says that Saccorhytus is the most primitive example of a category of animals called "deuterostomes" which are common ancestors of a broad range of species, including vertebrates (backboned animals).

Saccorhytus was about a millimetre in size, and is thought to have lived between grains of sand on the sea bed.

http://ichef.bbci.co.uk/news/624/cpsprodpb/11B4F/production/_93872527_xx65--269.jpgSaccorhytus was also covered with a thin, relatively flexible skin and muscles. It probably moved around by wriggling / Jian Han, Northwest University, China

The researchers were unable to find any evidence that the animal had an anus, which suggests that it consumed food and excreted from the same orifice.

The study was carried out by an international team of researchers, from the UK, China and Germany. Among them was Prof Simon Conway Morris, from the University of Cambridge.

He told BBC News: "To the naked eye, the fossils we studied look like tiny black grains, but under the microscope the level of detail as jaw-dropping.

"We think that as an early deuterostome this may represent the primitive beginnings of a very diverse range of species, including ourselves. All deuterostomes had a common ancestor, and we think that is what we are looking at here."

Degan Shu, from Northwest University in Xi'An, Shaanxi Province, where the fossils were found, said: "Saccorhytus now gives us remarkable insights into the very first stages of the evolution of a group that led to the fish, and ultimately, to us."

Until now, the deuterostome groups discovered were from between 510 to 520 million years ago. These had already begun to diversify into not just the vertebrates, the group to which we and our ancestors belong and animals such as starfish and sea urchins.

Because they looked so different from one another, it was difficult for the scientists to determine what an earlier, common ancestor might have looked like.

The study suggests that its body was symmetrical, which is a characteristic inherited by many of its evolutionary descendants, including humans.

Saccorhytus was also covered with a thin, relatively flexible skin and muscles, leading the researchers to conclude that it moved by contracting its muscles and got around by wriggling.

The researchers say that its most striking feature is its large mouth, relative to the rest of its body. They say that it probably ate by engulfing food particles, or even other creatures.

Also interesting are the conical structures on its body. These, the scientists suggest, might have allowed the water that it swallowed to escape and so might have been a very early version of gills.

First Known Dinosaur Brain Fossil Discovered

The 133-million-year-old specimen is a stunningly well-preserved sample of mineralized tissue from inside a Cretaceous dinosaur’s skull.

An unassuming lump found on a Sussex beach in 2004 contains the first known fossilized brain tissue from a dinosaur.

The 133-million-year-old fossil belongs to a relative of Iguanodon, an iconic herbivorous dinosaur that lived during the early Cretaceous. The fossil mostly consists of an endocast—a sediment cast of the skull cavity where the dinosaur’s brain resided.

Typically, endocasts give vital but indirect information about the brains of fossilized animals, as these sensitive organs are often the first to decay. But this endocast’s top surface contains microscopic features that appear to be directly mineralized bits of brain tissue.

Fossilized Dinosaur Brain Discovered in England

A piece of a dinosaur's brain has been found in Sussex, England. The fossilized brain tissue is thought to be from a species similar to Iguanodon, large herbivores that lived about 133 million years ago.

Fibrous textures across the endocast surface probably started as pieces of the meninges, the tough, protective membranes that envelop and nurture the brain. Mineralized networks of blood vessels—some smaller in width than a human hair—crisscross the surface. And tantalizingly, ripples in the preserved meninges might trace some of the folds in the cortex, the wrinkled outer layer of the brain.

“That is the nearest I suspect we’re ever going to get to the whole [brain],” says paleontologist David Norman of the University of Cambridge, one of the researchers who worked on the fossil. The remarkable find was announced on October 27 at the Society of Vertebrate Paleontology’s annual meeting in Utah.

High-resolution scans of the fossil revealed signs that the dinosaur’s meninges and overall brain structure resembled those of living birds and crocodilians. Although it’s tricky to extrapolate the dinosaur’s intelligence from the fossil, Norman and his colleagues say that based on it and other endocasts, the animal was at least as smart as modern crocodilians.

Pickled Brains

Soft tissue preservation in fossils is extremely rare, in part because it requires exacting chemical conditions to occur. Previously described dinosaur fossils have captured skin, organs, and even red blood cells. (Read about a fossil fish with an exquisitely preserved heart of stone.)

Based on the brain fossil’s minerals and orientation, Norman and his colleagues believe that the dinosaur sank into a stagnant pond after it died, flipping belly up as it descended to leave its head upside down and partially buried in the lake bed sediments.

The animal’s braincase served as a natural bowl, cradling the collapsed brain as the pond’s acidic, low-oxygen waters essentially pickled its membranes. As the waters ate away at the dinosaur’s blood and bone, the corrosion freed charged atoms that replaced the pickled tissues with minerals—preserving their impressions 133 million years later, down to the microscopic level.

The animal’s braincase served as a natural bowl, cradling the collapsed brain as the pond’s acidic, low-oxygen waters essentially pickled its membranes.

“It looks like a very exceptional specimen, for sure,” says Ohio University paleontologist Lawrence Witmer, an expert on dinosaur brain evolution who wasn’t involved with the study. “Soft tissue preservation of any kind gets us excited, and for those of us looking at the brain, potentially getting a glimpse into what the brain is like blows us away.”

The ancient brain first came to light in late 2004, when fossil hunter Jamie Hiscocks combed the beaches of Bexhill, some 50 miles southeast of London, after a winter storm. As he prowled the fossil-rich shore by torchlight, an unusually shaped object jumped out at him among the piles of rock debris.

In short order, Hiscocks and his brother concluded that the fossil was an endocast—but he remained struck by its unusual preservation, eventually leading him to ask Oxford paleobiologist Martin Brasier for his opinion.

“Martin knew immediately we had something special here, so I agreed to loan the specimen to him,” Hiscocks writes in an email. “In his initial email to me, he asked if I’d ever heard of dinosaur brain cells being preserved in the fossil record. I knew exactly what he was getting at. I was amazed to hear this coming from a world-renowned expert like him.

“Not in my wildest dreams did I ever think I would find anything like this,” continues Hiscocks. And he’s no stranger to significant discoveries: Hiscocks also found the world’s oldest spiderweb fossil, which was described in 2008.

In 2011, Brasier brought the brain fossil to the attention of Norman, his longtime friend and colleague. Norman’s first read: The endocast was mostly made of sediments encrusted with a thin layer of mineralized soft tissue. Brasier, on the other hand, was more bullish about the endocast, holding on to the hope that the fossil was an entire dinosaur brain.

“We then went into this prolonged argumentative debate between friends—the sort of stuff you argue about over a beer,” says Norman. But the two could never agree, leading Norman in 2013 to write down his interpretation of the fossil for Brasier’s reference.

But Brasier never replied to Norman in life: In December 2014, he died suddenly in a car crash, shocking the paleontological community.

A few months later, Brasier’s former Ph.D. student Alex Liu was sorting through Brasier’s papers when he came across Norman’s letter.

“Martin had gone through it in detail, and after each paragraph, [he had written] ‘agreed,’” says Norman. “He had completely turned around to my way of thinking,” he adds, even embracing Norman’s flip-and-pickle explanation for how the tissues mineralized.

Norman and Liu then resumed work on the fossil, conducting additional scans that revealed the extra details. Their paper will be included in a special publication of Earth System Evolution and Early Life from the Geological Society of London honoring Brasier’s life.

Smart Search

Future studies may reveal even more about the potential link between this ancient brain and the noggins of modern animals, including 3-D scans that directly compare the dinosaur’s brain structure to that of bird and crocodilian brains.

Amy Balanoff, a research scientist with Johns Hopkins University’s Center for Functional Anatomy and Evolution, says she isn’t yet fully convinced of the brain tissues, but she looks forward to seeing more detailed information about the fossil.

“Confirmation in science is a long process, and this publication is the first step toward that end,” she writes in an email. “I have a feeling that because this is such a sensational find, it will be thoroughly examined by the scientific community.”

To that end, Hiscocks and Norman are working to place the fossil, currently in Hiscock’s possession, in a publicly accessible museum collection.

Beyond its anatomical value, Norman and Witmer say that the Bexhill fossil’s real significance comes from how it expands the realm of possible tissues that can be preserved in the fossil record.

“These are the kinds of things we don’t expect to see, and what makes this [fossil] so important is that now we can look,” says Witmer. “Things that change our search image wind up being the most important finds.”

Although Norman doesn’t think that fossils like the Bexhill specimen will spark their own research program—he calls it “an interesting one-off”—he says he will double back to endocasts he has examined previously, to be sure he didn’t miss similarly revealing surface features.

“It never really occurred to me that there could be mineralization of the tissues in that area, because the brain is so fragile,” he says. “It’s putting a flag up the pole.”

Wild chimpanzee mothers teach young to use tools

The first documented evidence of wild chimpanzee mothers teaching their offspring to use tools has been captured by video cameras set to record chimpanzee tool-using activity at termite mounds in the Nouabalé-Ndoki National Park in the Republic of Congo, according to new research from anthropologists at Washington University in St. Louis.

"Wild chimpanzees are exceptional tool users, but in contrast to humans, there has been little evidence to date that adult chimpanzees teach youngsters tool skills," said Stephanie Musgrave, the study's first author and an anthropology graduate student in Arts & Sciences.

"We found that mother chimpanzees in the Goualougo Triangle teach by transferring termite-fishing probes to their offspring," Musgrave said. "In this population, chimpanzees select specific herb species to make their fishing probes, and they produce probes that have a particular brush-tipped design. By sharing tools, mothers may teach their offspring the appropriate material and form for manufacturing fishing probes."

Published in the journal Scientific Reports, the study is based on research conducted in partnership with the Wildlife Conservation Society, the Lincoln Park Zoo, the Max Planck Institute and Franklin and Marshall College. The findings have important implications for the evolution of teaching.

"It is easy for us to take for granted the importance of sharing information to learn complex skills, as it is ubiquitous in humans," said Crickette Sanz, associate professor of biological anthropology in Arts & Sciences at Washington University and co-author of the study. "Our research shows that the evolutionary origins of this behavior are likely rooted in contexts where particular skills are too challenging for an individual to invent on their own."

Musgrave, Sanz and colleagues used video to capture examples of wild chimpanzee mothers transferring specialized termite-gathering tools to less-skilled, immature chimpanzees. These transfers, which are costly to tool donors but beneficial to tool recipients, meet the scientific criteria for teaching in wild apes.

"Tool transfers are costly for mothers, whose ability to forage for termites is reduced, but are beneficial for offspring, who gain increased opportunity to learn tool skills and gather termites. This is the first such evidence satisfying these criteria for teaching in wild apes," Musgrave said.

"Identifying teaching among wild animals is difficult because one has to quantify the impact of possible teaching behaviors on both the teacher and the learner," Musgrave said. "Using video footage from remote camera traps placed at termite nests in the chimpanzees' home range, we were able to observe and quantify how sharing tools affected those who relinquished their tools as well as those who received them."

Chimpanzees are exceptional among animals for their remarkable propensity to make and use tools. Since different groups of chimpanzees use different types of tools, the teaching process also may need to be customized to address local conditions.

"Studying how young chimpanzees learn the tool skills particular to their group helps us to understand the evolutionary origins of culture and technology and to clarify how human cultural abilities are similar to or different from those of our closest living relatives," Musgrave said.

The findings have interesting implications for identifying the cognitive underpinnings of teaching. In humans, teaching involves an understanding of others' abilities and the intention to help them learn. In this study, chimpanzee mothers both anticipated the youngsters' need for a tool and devised strategies to reduce the effort necessary to provide them.

In examples captured in this study's videos, mothers sometimes bring multiple tools to a termite nest; they may also divide their fishing probe in half lengthwise, giving one-half to their offspring and keeping the other half. This strategy provides their offspring with a usable tool without compromising their own ability to gather food, Musgrave said.

Washington University pioneered the use of remote video technology to study the behavior of wild chimpanzees in Congo, and now it is used at nearly every ape research site across Africa. "It is a very effective means of monitoring wildlife without increasing human impact. Our camera array also provides a means of monitoring the health of the forest, as other endangered species such as western lowland gorillas, forest elephants, and leopards are 'captured' on film," Sanz said.

"In addition to our traditional tracking of wild chimpanzees through the forest each day, this remote video technology has been a force multiplier in expanding the scope of our research to several other chimpanzee communities," Sanz said. "We have observed a generation of chimpanzee kids learn how to use these tool sets, without having to spend a decade habituating them to human presence or risk exposing them to anthropogenic diseases."

Video: https://vimeo.com/186308470

The bird that refuses to land: New study records seabirds staying aloft for two consecutive months

Cursed with being a seabird that cannot float, a new study has identified the unusual coping tactic used by tropical frigate birds during cross-ocean journeys: They simply refuse to stop flying.

“The juveniles in particular, who leave their birthplace for the first time, can remain airborne for over two months without touching ground,” said a statement by the French National Centre for Scientific Research, which funded the study.

The two- to four-pound birds live exclusively off flying fish, have an uncanny ability to dodge tropical cyclones and can even sleep in mid-air.

Excerpt from Independence days, sur les traces des
jeunes prédateurs marins, a film by Aurélien Prudor and Henri Weimerskirch

The French research agency called the birds “astute strategists” capable of crossing the Indian Ocean simply by riding the trade winds.

It’s called a “roller-coaster” flight path; the birds catch updrafts and wind to soar to as high as 4,000 metres before gliding back down. By this method, the bird can travel hundreds of kilometres while barely moving its wings.

Prepared by a team of French, Canadian, German and British scientists, the study began by catching 50 of the elusive seabirds at Europa Island, a remote tropical atoll halfway between Mozambique and Madagascar.

The birds were strapped to transmitters that recorded their geographic position, altitude and how often they beat their wings. Researchers then watched as the frigates carried out their epic migration from southeast Africa to Indonesia.

Google Maps

While scientists generally knew that the frigate could stay aloft for long periods, the data showed the sheer intensity of the birds’ commitment to continual flight. Given that the frigates need to travel in circles to stick with the winds, their meandering path across the Indian Ocean can be as long as 34,000 km — roughly four times the width of Canada at its widest point.

Normally, a bird on a trans-oceanic migration will break up the journey by touching down on the ocean’s surface to bob around for a while. But despite living almost all of its life over the sea the frigate is alone among seabirds in not having waterproof feathers — and would sink if it tried to tread water.

But what the frigate lacks in waterproofing, it makes up for with gliding ability. With wingspans as wide as 2.3 metres, roughly equivalent to the length of a car, the birds have the largest wing-to-weight ratio of any bird on earth.

“The frigate is a bird built for gliding,” said a video accompanying the new research, which is published in this month’s edition of the journal Science.

Excerpt from Independence days, sur les traces des
jeunes prédateurs marins, a film by Aurélien Prudor and Henri Weimerskirch

The awkwardness of their giant wings appears to give the frigate a steep learning curve in how to fly.

The average crow or pigeon can be flying about mere weeks after hatching. A newborn frigate, meanwhile, will be grounded for an incredible six months or more before it can fly comfortably.

With this new research, science now knows the frigate is roughly on par with the human record for continuous flight. In 1959, Robert Timm and John Cook kept a Cessna aloft for 64 consecutive days by refuelling from a speeding truck on the ground.

The record for longest solo flight by a human, meanwhile, is only five days. That record was set last year by Swiss businessman André Borschberg flying a solar-powered aircraft.

Incredibly, though, the frigate bird is not even close to the world record for continuous flight. Alpine swifts, which migrate annually from Africa to Switzerland, can stay aloft for as long as 200 days.

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