YOU keep him waiting for three hours. And if you told that joke in Africa, you'd get more hearty laughs than in Asia. Naturalists have discovered orang-utans and other Asian apes laugh less than their African cousins, such as gorillas and chimps. And they also found that, while humans first learned to laugh from their ape ancestors millions of years ago, we have since learned to use laughter to sneer, mock and ridicule.
'Our observations showed strong differences in the use of laughter between the Asian great apes (orang-utans) and the African great apes (gorillas, chimpanzees and bonobos),' said Dr Marina Davila Ross, of the UK's University of Portsmouth.
'Asian apes and humans laugh clearly more often.'
Evolution has enabled humans to use laughter to mock others while apes simply laugh to enjoy themselves and influence others, she concluded.
'But something happened in the last 5 million years which means humans use laughter for a much wider range of situations.'
Dr Ross, who worked with the University of Veterinary Medicine in Germany, also showed sounds other than laughter can evolve in the context of tickling. Mammals, including flying foxes, make sounds when they are tickled but they are not necessarily laughing.
Metro Ireland, 12 January 2010, p5.
Showing posts with label evolution. Show all posts
Showing posts with label evolution. Show all posts
Tuesday, 12 January 2010
Saturday, 9 January 2010
Neanderthal 'make-up' discovered
Saturday, 9 January 2010
Scientists claim to have the first persuasive evidence that Neanderthals wore "body paint" 50,000 years ago.
The team report in Proceedings of the National Academy of Sciences (PNAS) that shells containing pigment residues were Neanderthal make-up containers.
Scientists unearthed the shells at two archaeological sites in the Murcia province of southern Spain.
The team says its find buries "the view of Neanderthals as half-wits" and shows they were capable of symbolic thinking.
Professor Joao Zilhao, the archaeologist from Bristol University in the UK, who led the study, said that he and his team had examined shells that were used as containers to mix and store pigments.
Black sticks of the pigment manganese, which may have been used as body paint by Neanderthals, have previously been discovered in Africa.
"[But] this is the first secure evidence for their use of cosmetics," he told BBC News. "The use of these complex recipes is new. It's more than body painting."
The scientists found lumps of a yellow pigment, that they say was possibly used as a foundation.
They also found red powder mixed up with flecks of a reflective brilliant black mineral.
Some of the sculpted, brightly coloured shells may also have been worn by Neanderthals as jewellery.
Until now it had been thought by many researchers that only modern humans wore make-up for decoration and ritual purposes.
There was a time in the Upper Palaeolithic period when Neanderthals and humans may have co-existed. But Professor Zilhao explained that the findings were dated at 10,000 years before this "contact".
"To me, it's the smoking gun that kills the argument once and for all," he told BBC News.
"The association of these findings with Neanderthals is rock-solid and people have to draw the associations and bury this view of Neanderthals as half-wits."
Professor Chris Stringer, a palaeontologist from the Natural History Museum in London, UK, said: "I agree that these findings help to disprove the view that Neanderthals were dim-witted.
But, he added that evidence to that effect had been growing for at least the last decade.
"It's very difficult to dislodge the brutish image from popular thinking," Professor Stringer told BBC News. "When football fans behave badly, or politicians advocate reactionary views, they are invariably called 'Neanderthal', and I can't see the tabloids changing their headlines any time soon."
Hybrid boy?
Another study published in the same issue of PNAS provides intriguing evidence about the relationship between humans and Neanderthals.
An international team of researchers examined teeth from the skeleton of a human child that was discovered in Portugal in the late 1990s.
It was suggested by some scientists at the time that this skeleton, which dates from the Upper Palaeolithic period - between 10,000 and 40,000 years ago - might have been the product of human and Neanderthal interbreeding.
The researchers found that the skeleton's teeth shared some features with Neanderthals rather than modern humans.
Although this does not settle the argument of whether the child was a hybrid, it does indicate, the researchers write, that "these earlier Upper Palaeolithic humans are not simply older versions of [today's] humanity".
http://news.bbc.co.uk/1/hi/sci/tech/8448660.stm
(Submitted by D.R. Shoop)
Scientists claim to have the first persuasive evidence that Neanderthals wore "body paint" 50,000 years ago.
The team report in Proceedings of the National Academy of Sciences (PNAS) that shells containing pigment residues were Neanderthal make-up containers.
Scientists unearthed the shells at two archaeological sites in the Murcia province of southern Spain.
The team says its find buries "the view of Neanderthals as half-wits" and shows they were capable of symbolic thinking.
Professor Joao Zilhao, the archaeologist from Bristol University in the UK, who led the study, said that he and his team had examined shells that were used as containers to mix and store pigments.
Black sticks of the pigment manganese, which may have been used as body paint by Neanderthals, have previously been discovered in Africa.
"[But] this is the first secure evidence for their use of cosmetics," he told BBC News. "The use of these complex recipes is new. It's more than body painting."
The scientists found lumps of a yellow pigment, that they say was possibly used as a foundation.
They also found red powder mixed up with flecks of a reflective brilliant black mineral.
Some of the sculpted, brightly coloured shells may also have been worn by Neanderthals as jewellery.
Until now it had been thought by many researchers that only modern humans wore make-up for decoration and ritual purposes.
There was a time in the Upper Palaeolithic period when Neanderthals and humans may have co-existed. But Professor Zilhao explained that the findings were dated at 10,000 years before this "contact".
"To me, it's the smoking gun that kills the argument once and for all," he told BBC News.
"The association of these findings with Neanderthals is rock-solid and people have to draw the associations and bury this view of Neanderthals as half-wits."
Professor Chris Stringer, a palaeontologist from the Natural History Museum in London, UK, said: "I agree that these findings help to disprove the view that Neanderthals were dim-witted.
But, he added that evidence to that effect had been growing for at least the last decade.
"It's very difficult to dislodge the brutish image from popular thinking," Professor Stringer told BBC News. "When football fans behave badly, or politicians advocate reactionary views, they are invariably called 'Neanderthal', and I can't see the tabloids changing their headlines any time soon."
Hybrid boy?
Another study published in the same issue of PNAS provides intriguing evidence about the relationship between humans and Neanderthals.
An international team of researchers examined teeth from the skeleton of a human child that was discovered in Portugal in the late 1990s.
It was suggested by some scientists at the time that this skeleton, which dates from the Upper Palaeolithic period - between 10,000 and 40,000 years ago - might have been the product of human and Neanderthal interbreeding.
The researchers found that the skeleton's teeth shared some features with Neanderthals rather than modern humans.
Although this does not settle the argument of whether the child was a hybrid, it does indicate, the researchers write, that "these earlier Upper Palaeolithic humans are not simply older versions of [today's] humanity".
http://news.bbc.co.uk/1/hi/sci/tech/8448660.stm
(Submitted by D.R. Shoop)
Friday, 8 January 2010
Earliest Four-Limbed Animals Left Mud Tracks
The finding of 395-million-year-old footprints in Poland turns back the clock on the evolution of four-legged creatures.
By Jennifer Viegas Wed Jan 6, 2010 07:57 AM ET
The fossilized footprints from these animals are 18 million years older than the earliest tetrapod body fossils, pushing the emergence of four-limbed creatures back to at least the early Middle Devonian period, according to two papers published in the latest issue of the journal Nature.
Tracks left behind by the animals 397 million years ago show how they walked on their short, thick legs through the mud of what was once a coral reef lagoon. That type of location, with its regular tides and abundant food sources consisting of "washed-up dead animals," likely set the stage for the fish-to-land animal transition, according to the authors.
The crawlers have not yet been identified, but co-author Per Ahlberg told Discovery News that they were "basal tetrapods, the common ancestral stock of all the living tetrapod groups."
Dogs, cats, humans and any other animal with four limbs fall into that large overall group.
But there was something fishy about these early animals.
"There isn't anything living today with the strange combination of fish and tetrapod-like characteristics that we see in the earliest fossil tetrapods," said Ahlberg, an Uppsala University Professor of Evolutionary Organismal Biology.
Ahlberg and his colleagues found and studied the tracks at what is now the Zachelmie Quarry in southeastern Poland. Their analysis shows some of the animals appear to have moved in a straight line without dragging their bodies on the ground, while others had a less symmetrical gait.
The largest of the individual prints shows not just feet, but the animal's "whole limb as far as the knee," the researchers wrote. On one fossil track, "the tip of each triangular toe shows a small distinct cushion or pad," they added.
Before the discovery of these tracks, it was thought certain fish evolved into four-limbed animals during the Givetian Period, 391 to 385 million years ago. Fossils seemed to neatly support this timing for the fin-to-limb gradual change, since some fish, known as elpistostegids, appeared to belong to a mid-point stage where the fish had tetrapod-like heads and bodies, but retained fish characteristics, such as paired fins.
"In fact, tetrapods and elpistostegids coexisted for at least 10 million years," the researchers point out. "This implies that the elpistostegid morphology was not a brief transitional stage, but a stable adaptive position in its own right."
The scientists compare the coexistence of four-limbed animals and these fish with what happened to dinosaurs and birds. Dinosaurs didn't all just evolve into birds. Feathered and winged theropod dinosaurs were still around long after the first birds appeared about 150 million years ago.
Another revision to the animal history books concerns the habitat of the first tetrapods, according to Philippe Janvier and Gael Clement of the National Museum of Natural History in Paris.
In a separate commentary in Nature, they call the new finds a "stunning discovery." They write that the sea and lagoon location described by Ahlberg and his colleagues "is at odds with the long-held view that river deltas and lakes were the necessary environments for the transition from water to land during vertebrate evolution."
Given this difference, and the very early date of the tracks, Janvier and Clement believe the new findings "lob a grenade" into accepted theories of the fish-to-tetrapod transition.
http://news.discovery.com/animals/tetrapod-tracks-poland.html
By Jennifer Viegas Wed Jan 6, 2010 07:57 AM ET
This is a sketch of a Devonian tetrapod making tracks. It is based on a species from the Late Devonian of Greenland but is a reasonable approximation to the track-maker of newly-found prints in Poland.
Per Ahlberg
The world's first four-limbed animals, called tetrapods, crawled on land much earlier than scientists thought, judging by tracks left behind by some of the animals in a prehistoric Polish lagoon.Per Ahlberg
The fossilized footprints from these animals are 18 million years older than the earliest tetrapod body fossils, pushing the emergence of four-limbed creatures back to at least the early Middle Devonian period, according to two papers published in the latest issue of the journal Nature.
Tracks left behind by the animals 397 million years ago show how they walked on their short, thick legs through the mud of what was once a coral reef lagoon. That type of location, with its regular tides and abundant food sources consisting of "washed-up dead animals," likely set the stage for the fish-to-land animal transition, according to the authors.
The crawlers have not yet been identified, but co-author Per Ahlberg told Discovery News that they were "basal tetrapods, the common ancestral stock of all the living tetrapod groups."
Dogs, cats, humans and any other animal with four limbs fall into that large overall group.
But there was something fishy about these early animals.
"There isn't anything living today with the strange combination of fish and tetrapod-like characteristics that we see in the earliest fossil tetrapods," said Ahlberg, an Uppsala University Professor of Evolutionary Organismal Biology.
Ahlberg and his colleagues found and studied the tracks at what is now the Zachelmie Quarry in southeastern Poland. Their analysis shows some of the animals appear to have moved in a straight line without dragging their bodies on the ground, while others had a less symmetrical gait.
The largest of the individual prints shows not just feet, but the animal's "whole limb as far as the knee," the researchers wrote. On one fossil track, "the tip of each triangular toe shows a small distinct cushion or pad," they added.
Before the discovery of these tracks, it was thought certain fish evolved into four-limbed animals during the Givetian Period, 391 to 385 million years ago. Fossils seemed to neatly support this timing for the fin-to-limb gradual change, since some fish, known as elpistostegids, appeared to belong to a mid-point stage where the fish had tetrapod-like heads and bodies, but retained fish characteristics, such as paired fins.
"In fact, tetrapods and elpistostegids coexisted for at least 10 million years," the researchers point out. "This implies that the elpistostegid morphology was not a brief transitional stage, but a stable adaptive position in its own right."
The scientists compare the coexistence of four-limbed animals and these fish with what happened to dinosaurs and birds. Dinosaurs didn't all just evolve into birds. Feathered and winged theropod dinosaurs were still around long after the first birds appeared about 150 million years ago.
Another revision to the animal history books concerns the habitat of the first tetrapods, according to Philippe Janvier and Gael Clement of the National Museum of Natural History in Paris.
In a separate commentary in Nature, they call the new finds a "stunning discovery." They write that the sea and lagoon location described by Ahlberg and his colleagues "is at odds with the long-held view that river deltas and lakes were the necessary environments for the transition from water to land during vertebrate evolution."
Given this difference, and the very early date of the tracks, Janvier and Clement believe the new findings "lob a grenade" into accepted theories of the fish-to-tetrapod transition.
http://news.discovery.com/animals/tetrapod-tracks-poland.html
Wednesday, 6 January 2010
Fossil tracks record 'oldest land-walkers'
Wednesday, 6 January 2010
By Jonathan Amos
Science correspondent, BBC News
The oldest evidence of four-legged animals walking on land has been discovered in southeast Poland.
Rocks from a disused quarry record the "footprints" of unknown creatures that lived about 397 million years ago.
Scientists tell the journal Nature that the fossil trackways even retain the impressions left by the "toes" on the animals' feet.
The team says the find means that land vertebrates appeared millions of years earlier than previously supposed.
"This place has yielded what I consider to be some of the most exciting fossils I've ever encountered in my career as a palaeontologist," said team member Per Ahlberg from Uppsala University, Sweden.
"[They are] fossil of footprints that give us the earliest record of how our very distant ancestors moved out of the water and moved on to the land and took their first steps."
Numerous trackways have been identified in the Zachelmie Quarry in the Holy Cross Mountains.
They represent the movements of many animals as they scurried around what would have been a tropical muddy shoreline in the Middle Devonian Period of Earth history.
Slabs of carbonate rock are dappled with prints that range in size and detail.
Some indentations are obscured where successive animals have trampled over the same patch of ground; but others retain exquisite features of the pads and digits that made them.
The animals were probably crocodile-like in appearance and lived an amphibian-like existence (although those specific animal forms did not appear until many millions of years later).
The dimensions of the prints suggest some individuals were more than two metres long.
The Polish and Swedish scientific team analysed the trackway patterns to reconstruct how the ancient creatures would have moved their "hips", "elbows" and "knees".
This confirms that only true four-legged animals, or tetrapods, could have left the marks.
Theory holds that the first land creatures evolved from fish that had pairs of lobed fins. The precise timing of this transition has been a dynamic field of study in recent years.
The assumption of palaeontologists had been that there was a swift but stepwise transition between water and land.
Perhaps the most notable fossil in this story is an organism called Tikaalik rosea, an animal that had features intermediate between fish and tetrapods.
But Tiktaalik lived about 375 million years ago; and although there are slightly older transition fossils, the Zachelmie Quarry tetrapods break the neat and simple timeline.
"The discovery of undoubted trackways from the earliest period of the Eifelian - that is 379 million years ago - pushes back the divergence between fishes and the four-legged vertebrates by about 18 million years, if not probably more," commented Dr Philippe Janvier from the National Museum of Natural History, Paris, France.
"I suspect that now we can push the divergence back to the Emsian stage, maybe 400 million years ago. That's surprising, but this is what the fossil evidence tells us," the independent researcher told BBC News.
Another key surprise from the research is the recognition that these tetrapods lived in a marine environment, perhaps a coral lagoon.
The favoured origin before now for the emergence of tetrapods had been marshy environments, such as deltas or lakes where freshwater dominated.
The team behind the latest research said the new explanation made sense because it would have allowed marine ancestors of tetrapods gradually to acquire terrestrial competence while accessing a new and essentially untouched resource of food washed up with the tides.
"In the intertidal setting, you've got a smorgasbord laid out twice a day," said Dr Ahlberg.
"Every time the tide goes out, it leaves behind this drift-line of dead and moribund animals. All this was just left there for vertebrates - our ancestors - to emerge on to land and pick them off."
http://news.bbc.co.uk/1/hi/sci/tech/8443879.stm
By Jonathan Amos
Science correspondent, BBC News
The oldest evidence of four-legged animals walking on land has been discovered in southeast Poland.
Rocks from a disused quarry record the "footprints" of unknown creatures that lived about 397 million years ago.
Scientists tell the journal Nature that the fossil trackways even retain the impressions left by the "toes" on the animals' feet.
The team says the find means that land vertebrates appeared millions of years earlier than previously supposed.
"This place has yielded what I consider to be some of the most exciting fossils I've ever encountered in my career as a palaeontologist," said team member Per Ahlberg from Uppsala University, Sweden.
"[They are] fossil of footprints that give us the earliest record of how our very distant ancestors moved out of the water and moved on to the land and took their first steps."
Numerous trackways have been identified in the Zachelmie Quarry in the Holy Cross Mountains.
They represent the movements of many animals as they scurried around what would have been a tropical muddy shoreline in the Middle Devonian Period of Earth history.
Slabs of carbonate rock are dappled with prints that range in size and detail.
Some indentations are obscured where successive animals have trampled over the same patch of ground; but others retain exquisite features of the pads and digits that made them.
The animals were probably crocodile-like in appearance and lived an amphibian-like existence (although those specific animal forms did not appear until many millions of years later).
The dimensions of the prints suggest some individuals were more than two metres long.
The Polish and Swedish scientific team analysed the trackway patterns to reconstruct how the ancient creatures would have moved their "hips", "elbows" and "knees".
This confirms that only true four-legged animals, or tetrapods, could have left the marks.
Theory holds that the first land creatures evolved from fish that had pairs of lobed fins. The precise timing of this transition has been a dynamic field of study in recent years.
The assumption of palaeontologists had been that there was a swift but stepwise transition between water and land.
Perhaps the most notable fossil in this story is an organism called Tikaalik rosea, an animal that had features intermediate between fish and tetrapods.
But Tiktaalik lived about 375 million years ago; and although there are slightly older transition fossils, the Zachelmie Quarry tetrapods break the neat and simple timeline.
"The discovery of undoubted trackways from the earliest period of the Eifelian - that is 379 million years ago - pushes back the divergence between fishes and the four-legged vertebrates by about 18 million years, if not probably more," commented Dr Philippe Janvier from the National Museum of Natural History, Paris, France.
"I suspect that now we can push the divergence back to the Emsian stage, maybe 400 million years ago. That's surprising, but this is what the fossil evidence tells us," the independent researcher told BBC News.
Another key surprise from the research is the recognition that these tetrapods lived in a marine environment, perhaps a coral lagoon.
The favoured origin before now for the emergence of tetrapods had been marshy environments, such as deltas or lakes where freshwater dominated.
The team behind the latest research said the new explanation made sense because it would have allowed marine ancestors of tetrapods gradually to acquire terrestrial competence while accessing a new and essentially untouched resource of food washed up with the tides.
"In the intertidal setting, you've got a smorgasbord laid out twice a day," said Dr Ahlberg.
"Every time the tide goes out, it leaves behind this drift-line of dead and moribund animals. All this was just left there for vertebrates - our ancestors - to emerge on to land and pick them off."
http://news.bbc.co.uk/1/hi/sci/tech/8443879.stm
Saturday, 2 January 2010
Bass Strait barnacle 300 million-year-old king of species
December 30, 2009
A RARE barnacle found only in Bass Strait is the oldest of the species, as well as one of its most unique members, according to researchers who came across the crustacean by a lucky accident.
The tiny ibliform barnacle, which is just 2.5 millimetres long, dates back to the Paleozoic era, about 300 million years ago.
That means the ibliform barnacle pre-dates all other types of barnacles and gives researchers a clue as to how the species evolved.
''Their earliest forms evolved from Bass Strait and the Tasman Sea,'' said John Buckeridge, professor of natural resources engineering at RMIT University.
And unlike most barnacles, which rely on shells and camouflage to protect them from predators, Professor Buckeridge said the cream-coloured barnacle used the toxic substance bromine, collected from sea water, to make itself unpalatable to predators such as carnivorous snails, small fish and crustaceans.
The ibliform, however, has an incomplete shell that does not cover the barnacle's lower, vulnerable areas where the bromine-heavy parts are mostly concentrated.
Professor Buckeridge's research with RMIT research fellow Jessica Reeves, published this month in the journal Integrative Zoology, found up to 7 per cent of some parts of its body is bromine.
''That's a remarkably high percentage,'' Professor Buckeridge said. ''It's much higher than anything else I've ever seen apart from an algae, also found in Bass Strait. It would be more than unpalatable, it would be poisonous.''
He said there was only one other type of barnacle, the deep sea tetrachaelasma found in waters off Madagascar, which had bromine in its body.
''The shells of these ibliform are made of the same stuff as our teeth. It's a primitive feature not found in modern barnacles,'' Professor Buckeridge said.
The ibliform barnacle, which was recognised as a new species in 2006, is so rare that scientists have only six specimens.
It was found by accident after fishermen delivered a coral-like substance to Museum Victoria, not realising there was a barnacle attached.
http://www.theage.com.au/national/bass-strait-barnacle-300-millionyearold-king-of-species-20091229-lisj.html
A RARE barnacle found only in Bass Strait is the oldest of the species, as well as one of its most unique members, according to researchers who came across the crustacean by a lucky accident.
The tiny ibliform barnacle, which is just 2.5 millimetres long, dates back to the Paleozoic era, about 300 million years ago.
That means the ibliform barnacle pre-dates all other types of barnacles and gives researchers a clue as to how the species evolved.
''Their earliest forms evolved from Bass Strait and the Tasman Sea,'' said John Buckeridge, professor of natural resources engineering at RMIT University.
And unlike most barnacles, which rely on shells and camouflage to protect them from predators, Professor Buckeridge said the cream-coloured barnacle used the toxic substance bromine, collected from sea water, to make itself unpalatable to predators such as carnivorous snails, small fish and crustaceans.
The ibliform, however, has an incomplete shell that does not cover the barnacle's lower, vulnerable areas where the bromine-heavy parts are mostly concentrated.
Professor Buckeridge's research with RMIT research fellow Jessica Reeves, published this month in the journal Integrative Zoology, found up to 7 per cent of some parts of its body is bromine.
''That's a remarkably high percentage,'' Professor Buckeridge said. ''It's much higher than anything else I've ever seen apart from an algae, also found in Bass Strait. It would be more than unpalatable, it would be poisonous.''
He said there was only one other type of barnacle, the deep sea tetrachaelasma found in waters off Madagascar, which had bromine in its body.
''The shells of these ibliform are made of the same stuff as our teeth. It's a primitive feature not found in modern barnacles,'' Professor Buckeridge said.
The ibliform barnacle, which was recognised as a new species in 2006, is so rare that scientists have only six specimens.
It was found by accident after fishermen delivered a coral-like substance to Museum Victoria, not realising there was a barnacle attached.
http://www.theage.com.au/national/bass-strait-barnacle-300-millionyearold-king-of-species-20091229-lisj.html
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