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rasha kamel
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"Biologists combed through 28 years' worth of data on Magellanic penguins to search for signs that natural selection -- one of the main drivers of evolution -- may be acting on certain penguin traits".

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Biologists combed through 28 years' worth of data on Magellanic penguins to search for signs that natural selection -- one of the main drivers of evolution -- may be acting on certain penguin traits.
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"It has long puzzled scientists why, after 3 billion years of nothing more complex than algae, complex animals suddenly started to appear on Earth. Now, a team of researchers has put forward some of the strongest evidence yet to support the hypothesis that high levels of oxygen in the oceans were crucial for the emergence of skeletal animals 550 million years ago".
It has long puzzled scientists why, after 3 billion years of nothing more complex than algae, complex animals suddenly started to appear on Earth. Now, a team of researchers has put forward some of the strongest evidence yet to support the hypothesis that high levels of oxygen in the oceans were crucial for the emergence of skeletal animals 550 million years ago.
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"Pitiful scenes of cheetah cubs lying emaciated and bewildered highlight one of the cruellest but least-publicised examples of illegal wildlife trafficking.
Baby cheetahs are so prized as exotic pets that entire litters are seized from their mothers when they may only be four to six weeks old.
Each tiny animal can fetch as much as $10,000 on the black market and end up being paraded on social media by wealthy buyers in Gulf states.
But the trade exacts a terrible toll on a species that claims a superlative status as the fastest land animal on the planet but which now faces a serious threat to its survival.
According to the Cheetah Conservation Fund, some 1,200 cheetah cubs are known to have been trafficked out of Africa over the past 10 years but a shocking 85% of them died during the journey.
Dr Laurie Marker, the trust's director, describes the horrific conditions involved in shipping the animals from their habitats in northern Kenya, Somaliland and Ethiopia by land and sea to the Arabian Gulf.
"They're probably just thrown into a crate, living in their own faeces, travelling for days without proper food, and many of them end up dead on arrival at wherever that place would be, and maybe one or two living out of a pile that are dead."
And those that do make it into the hands of new owners usually die rapidly because they are denied the chance to exercise and are given an inadequate diet".
The illegal trade in cheetahs as exotic pets could help drive some of the remaining populations of these spectacular cats, which are already diminished, to extinction.
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"Despite evolving separately for 400 million years, some sharks and tuna share genetic traits linked to higher metabolism and quick swimming behaviour.
Tuna fish and the lamnid group of sharks, which includes great white sharks, share some similar traits that help make them super predators, including their style of swimming and their ability to stay warm.
Despite their genetic separation, new research led by Imperial College London reveals many genes in the two groups that give them this predatory edge. The genes, linked to similar traits such as metabolism, have been preferentially selected for in both groups – meaning that they are more likely to be passed on since they give the creature a survival advantage.
The team also found one identical gene in both groups that is linked with metabolism, and the creatures' ability to produce energy. This finding could help scientists unravel the relationship between genetics and physical traits. The research is published this month in Genome Biology and Evolution.
Study co-author Professor Vincent Savolainen from the Department of Life Sciences at Imperial said: "Lamnid sharks and tuna both have stiff bodies and tails that allow them to swim in bursts. They can also keep their temperature up in colder waters. Both of these things make them more effective predators, allowing them to snatch prey in usually inhospitable waters.
"These are simple traits, and ones that have evolved twice. They give us a great point to start really examining the underlying genetics and understanding the relationship to physical traits."
Genes in the body code for different proteins, the building blocks of all tissues and functions in the body. When a gene is activated, and produces proteins, the process is called gene expression.
However, it is difficult to directly link a single gene to a physical trait, such as metabolism, because gene expression can be different in different organisms, causing the resulting trait to be different.
Looking at examples of the same gene used in two different animals can provide scientists with important clues as to how the expression of a gene relates to the physical trait observed".
Despite evolving separately for 400 million years, some sharks and tuna share genetic traits linked to higher metabolism and quick swimming behaviour.
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"If you chop a magnet in half, you end up with two smaller magnets. Both the original and the new magnets have "north" and "south" poles.
But what if single north and south poles exist, just like positive and negative electric charges? These hypothetical beasts, known as "magnetic monopoles," are an important prediction in several theories.
Like an electron, a magnetic monopole would be a fundamental particle. Nobody has seen one yet, but many—maybe even most—physicists would say monopoles probably exist.
"The electric and magnetic forces are exactly the same force," says Wendy Taylor of Canada's York University. (Everything would be totally symmetric if there existed a magnetic monopole. There is a strong motivation by the beauty of the symmetry to expect that this particle exists)."
If you chop a magnet in half, you end up with two smaller magnets. Both the original and the new magnets have "north" and "south" poles.
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"When California houseboat residents heard their low, submarine hum in the 1980s, they thought it might be coming from noisy sewage pumps, military experiments or even extraterrestrials.
But this was the nocturnal hum of the midshipman fish; a courtship call, and the source of a biological secret scientists have now solved.
Researchers brought the fish into their lab to work out why they sang at night.
The US team's findings are published in the journal Current Biology".
Scientists solve the bizarre mystery of the fish that hums at night.
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"Poor diets are undermining the health of one in three of the world's people, an independent panel of food and agriculture experts has warned.
The report says under-nourishment is stunting the growth of nearly a quarter of children under five.
And by 2030 a third of the population could be overweight or obese.
The report by the Global Panel on Agriculture and Food Systems for Nutrition is being presented to the UN's Food and Agriculture Organisation.
The panel - which is led by the former President of Ghana John Kufuor and the former Chief Scientific Advisor to the UK Government Sir John Beddington - says two billion people lack the range of vitamins and minerals in their diet needed to keep them healthy".
As the population grows over the next 20 years half the world will be left malnourished, an independent panel of experts on food and agriculture warns.
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"Horses have joined a select group of animals that can communicate by pointing at symbols.
Scientists trained horses, by offering slices of carrot as an incentive, to touch a board with their muzzle to indicate if they wanted to wear a rug.
The horses' requests matched the weather, suggesting it wasn't a random choice.
A few other animals, including apes and dolphins, appear, like us, to express preferences by pointing at things.
Dr Cecilie Mejdell of the Norwegian Veterinary Institute, who led the research, said they wanted to find a way to ask the horse whether or not it liked wearing a blanket".
Horses have joined a select club of animals that can communicate by pointing to symbols, say scientists.
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"The copper used to make Ötzi's axe blade did not come from the Alpine region as had previously been supposed, but from ore mined in southern Tuscany. Ötzi was probably not involved in working the metal himself, as the high levels of arsenic and copper found in his hair had, until now, led us to assume. His murder over 5,000 years ago seems to have been brought about due to a personal conflict a few days before his demise, and the man from the ice, despite his normal weight and active life-style, suffered from extensive vascular calcification".
The copper used to make Ötzi's axe blade did not come from the Alpine region as had previously been supposed, but from ore mined in southern Tuscany. Ötzi was probably not involved in working the metal himself, as the high levels of arsenic and copper found in his hair had, until now, led us to assume. His murder over 5,000 years ago seems to have been brought about due to a personal conflict a few days before his demise, and the man from the ice...
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"A trio of researchers has presented their preliminary findings regarding a mitochondrial DNA study they have undertaken as part of an effort to learn more about the domestication history of the modern house cat. Evolutionary geneticist Eva-Maria Geigl gave the presentation at this year's International Symposium on Biomolecular Archaeology at the Oxford University Museum of Natural History.
To learn more about the ancestry of the common house cat, the researchers (which also included colleagues Thierry Grange and Claudio Ottoni) obtained mitochondrial DNA samples of 209 cats from multiple archaeological sites around the world—the ages of the remains ranged from approximately 15,000 years ago to just 300 years ago. After sequencing the samples, the researchers made some interesting discoveries surrounding the history of cats partnering with humans. The first was that there appeared to be two big migration waves—the first occurred not long after the development of agriculture by humans and the second shortly after the domestication of cats in ancient Egypt.
The researchers suggest that the first wave was likely the result of small cats coming into contact with humans due to hunting the increased populations of rodents consuming the grains they grew—the researchers found a link between cats in the Fertile Crescent and other parts of the Mediterranean. The second wave occurred several thousand years later and appeared to be driven by human migrations out of Egypt—the researchers found links between cats there and throughout Eurasia and parts of Africa—likely due, the team suggests, to farmers and seafaring travelers taking cats with them to reduce rat and mouse populations.
There were a couple of other surprises as well—one was that the fierce Vikings apparently had a soft spot for little kitties—one of them was found buried alongside its master in a common grave site that was dated back 1000 years. The other was that tabby cats did not evolve until Mediaeval times".
(Phys.org)—A trio of researchers has presented their preliminary findings regarding a mitochondrial DNA study they have undertaken as part of an effort to learn more about the domestication history of the modern house cat. ...
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"An international team of scientists led by The University of Manchester has used state-of-the-art X-ray methods to analyse the chemistry of feathers of birds, in order to discover the true colours of extinct ancient animals such as dinosaurs.
Melanin is the dominant pigment in mammals and birds that gives them either a black/dark brown colour, for example in ravens, or a reddish/yellow hue, as in foxes. The black pigment is called eumelanin, while the reddish type is pheomelanin.
Pioneering research at The University's Interdisciplinary Centre for Ancient Life has studied the feathers of modern birds in order to find long-lived chemical markers for these different pigments, so that traces may be reconstructed in fossil specimens.
In collaboration with the UK's Diamond Light Source x-ray laboratories and Stanford University in the USA, the scientists analysed feathers shed by birds housed in animal sanctuaries. Their research has been able to show that the trace metal zinc, when it is bonded to sulphur compounds in a specific way, is a reliable and sensitive indicator for the presence of pheomelanin within the distinct feathers of birds of prey.
This remarkable discovery means that scientists may perhaps now be able to go beyond monochrome depictions of extinct creatures, and make the first steps towards portraying colours based upon chemical evidence.
"A fundamental rule in geology is that the present is the key to the past" said Roy Wogelius, Professor of Geochemistry at The University of Manchester and senior author of the study. "This work on modern animals now provides another chemical 'key' for helping us to accurately reconstruct the appearance of long extinct animals".
"Melanin is a very important component in biology, but its exact chemistry is still not precisely known, especially as to how metals such as calcium, copper and zinc interact with it" said Nick Edwards, a Post Doctoral Research Associate at the University of Manchester and the lead author of the study. "Here we have used a new approach to probe these components of melanin and have found that there are subtle but measurable differences between the different types of melanin with regards to certain elements".
"The avian descendants of dinosaurs have kept the chemical key to unlocking colour precisely locked in their feather chemistry!" added Professor Phil Manning, co-author of the study".
An international team of scientists led by The University of Manchester has used state-of-the-art X-ray methods to analyse the chemistry of feathers of birds, in order to discover the true colours of extinct ancient animals ...
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"Iconic dinosaur shapes were present for at least a hundred million years on our planet in animals before those dinosaurs themselves actually appeared".
Iconic dinosaur shapes were present for at least a hundred million years on our planet in animals before those dinosaurs themselves actually appeared.
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Gender
Female
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Introduction
I had PhD in computational chemistry
I am working in archaeological analysis
I am interesting in geology, material science
and environmental sciences