Monday, February 29, 2016

Did all animal life on Earth begin with a sea sponge?





Genetic analysis of 640-million-year-old rocks suggests that the sea sponge may have been the first animal to develop on Earth.

Scientists estimate that there are about 8.7 million species of animals on Earth – give or take 1.3 million. But in the beginning there could be only one.
That animal was very likely the simple sea sponge, according to a study by researchers at the Massachusetts Institute of Technology in Cambridge.
Based on new genetic tests, the team of scientists can say with confidence that molecules produced by sea sponges have been found in 640-million-year-old rocks. These rocks significantly predate the Cambrian explosion, the period 540 million years ago in which most animal groups took over the planet, suggesting that sea sponges may have been the first animals.
The researchers write in the study, which was published Friday in the Proceedings of the National Academy of Sciences, that their testing provides “the oldest evidence for animal life.

“We brought together paleontological and genetic evidence to make a pretty strong case that this really is a molecular fossil of sponges,” explains David Gold, a post-doctoral researcher in MIT’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS), in a press release.
Paleontologists have long struggled to determine which type of animal was the first to the evolutionary line. While they have unearthed a large number of fossils from the start of the Cambrian explosion, the fossils that are known from before then are peculiar in many respects.
EAPS Professor Roger Summons has spent more than two decades searching for the animal kingdom’s extended evolutionary tree. His lab has been looking for clues in molecular fossils, trace amounts of molecules that have survived in ancient rocks long after the rest of an animal has decayed.
The so-called “‘sponge biomarker hypothesis” was first hypothesized in 1994 and partially confirmed in 2009. It focuses on 24-isopropylcholestane, a lipid molecule, or sterol, that scientists have found in unusually high amounts in Cambrian and slightly older rocks. Genetic testing by Dr. Gold adds “a further layer of evidence supporting” the theory that sponges or their ancestors might be their source, Dr. Summons said in the release.
The results of the study provide strong evidence that sea sponges appeared on Earth 640 million years ago, much earlier than any other life form.
“This brings up all these new questions: What did these organisms look like? What was the environment like? And why is there this big gap in the fossil record?” Gold says. “This goes to show how much we still don’t know about early animal life, how many discoveries there are left, and how useful, when done properly, these molecular fossils can be to help fill in those gaps.

Forgotten fossil reveals growth potential of carnivorous dinosaurs

"Our study shows how museums still play an important role in preserving specimens of primary scientific value," said study co-author Andrea Cau. By Brooks Hays   |   Feb. 29, 2016 at 10:32 AM

A rendering offers an idea of how large abelisaurs were. Photo by ICL
LONDON, Feb. 29 (UPI) -- After re-examining a fossilized femur bone belonging to an abelisaur specimen, researchers can say with more certainty how large these fearsome predators could become.
Based on their analysis, researchers at Imperial College London believe the femur belonged to an abelisaur weighing nearly two metric tons and stretching nine meters, or almost 30 feet. Those dimensions make it one of the largest abelisaurs ever found.
The new research was detailed in the journal PeerJ.
"Smaller abelisaur fossils have been previously found by paleontologists, but this find shows how truly huge these flesh eating predators had become," researcher Alessandro Chiarenza, study co-auhtor, said in a press release. "Their appearance may have looked a bit odd as they were probably covered in feathers with tiny, useless forelimbs, but make no mistake they were fearsome killers in their time."
Abelisauridae dinosaurs made up for their tiny forelimbs and odd appearance with massive hindquarters and deadly sharp teeth. They thrived in what is now northern Africa some 95 million years ago, though abelisaur fossils have been dated as far back as 170 million years ago and as recently as 66 million years ago.
The femur was originally found in a Moroccan deposit known as Kem Kem Beds -- famous for its abundance of predatory dino bones. The site has confounded researchers who believe it would have been impossible for so many carnivorous dinosaurs to coexist in such tight quarters.
New analysis suggests the sometimes violent geologic conditions that created Kem Kem Beds may have also mixed up the strata and chronology of the fossil record.
Other sites suggest abelisaur were inland hunters, somewhat separated from their closest cousins, who preferred to hunt fish near lakes and rivers.
"This fossil find, along with the accumulated wealth of previous studies, is helping to solve the question of whether abelisaurs may have co-existed with a range of other predators in the same region," Chiarenza explained. "Rather than sharing the same environment, which the jumbled up fossil records may be leading us to believe, we think these creatures probably lived far away from one another in different types of environments."
The fossil was not recently unearthed, but had been sitting in a museum drawer for several decades -- further proof that closeted collections hide nearly as many secrets as untouched earth.
"While palaeontologists usually venture to remote and inaccessible locations, like the deserts of Mongolia or the Badlands of Montana," added Andrea Cau, study co-author and researcher at the University of Bologna, "our study shows how museums still play an important role in preserving specimens of primary scientific value, in which sometimes the most unexpected surprises can be discovered."

Wednesday, February 24, 2016

The world's deadliest animal isn't a shark or even a human

Business Insider

The world's deadliest creature isn't what you'd expect.
A 2014 graphic from Bill Gates' blog outlined the number of deaths per year related to animals. Scroll down and you'll see the biggest offender — mosquitoes.


BiggestKillers_final_v8_no logo
(GatesNotes.com) Yes, mosquitoes — the pesky bugs that suck up blood and transmit viruses from person to person — are responsible for the most animal-related deaths.
"When it comes to killing humans, no other animal even comes close," Gates noted on the blog.
Malaria by itself is responsible for more than half of mosquito-related deaths, predominantly in sub-Saharan Africa, though that incidence fell by 37% between 2000 and 2015, according to the World Health Organization. Dengue fever, another mosquito-borne disease, has become a leading-cause of hospitalization and death among children in some Asian and Latin-American countries.
And it's not just deaths that mosquitoes are responsible for. The recent spread of the Zika virus in the Americas via mosquito has alerted the world to the impact the pest has. Once infected with Zika, only about 20% of people ever show symptoms, which most commonly include fever, rash, joint pain, and red eyes. One reason why Zika is troubling is because it has been linked with birth defects in babies whose mothers have had Zika symptoms and a neurological condition called Guillain-Barré Syndrome.
While Aedes aegypti has been singled out as the carrier of Zika and dengue, other mosquitoes like those in the Anopheles group carry malaria.


An Anopheles stephensi mosquito obtains a blood meal from a human host through its pointed proboscis in this undated handout photo obtained by Reuters...
(Thomson Reuters) An Anopheles stephensi mosquito obtains a blood meal from a human host through its pointed proboscis in this handout photo
Apart from vaccines, mosquito eradication is one of the best ways to curb the spread of deadly infectious diseases. Then, perhaps, there could be a new deadliest animal.


More From Business Insider

Sunday, February 21, 2016

Turmeric: Is This 'Miracle Food' the Real Deal? Here's What the Research Says

http://www.stack.com/ 



Unless you've been living under a rock for the past three months, you've probably heard about turmeric. If not, here's a quick rundown: Turmeric is a plant in the ginger family that's native to southwest India. Its root can be boiled, ground and baked to produce an orangish-yellowish powder. This powder, often referred to as ground turmeric or turmeric powder, has been a staple of Indian and Pakistani cuisine for thousands of years. Now, many Americans are also embracing it. So, why are we suddenly obsessed with this ancient spice?

Because it's being labeled across the internet as an incredibly powerful "superfood." Google "turmeric health benefits" and you'll find thousands of articles claiming turmeric can do everything under the sun. If you believe everything you read, turmeric can supposedly:
  • whiten teeth
  • reduce wrinkles
  • relieve pain
  • thicken hair
  • treat and prevent multiple forms of cancer
  • prevent Alzheimer's
  • increase weight loss
  • treat depression
  • improve sleep
  • pretty much anything else you could ever want
Pretty crazy, right? Well, don't go out and buy drums of turmeric quite yet. It's not uncommon for the benefits of trendy foods to get exaggerated, only to fade from the limelight when people realize those benefits are mostly hot air. That's why STACK dove into the research to see if turmeric really deserves to be the next big thing in nutrition.

The Secret Ingredient

 

Turmeric Powder

Before we address the research, let's check out the basic nutritional profile of ground turmeric. One tablespoon contains 24 calories, .7 grams of fat, 1.4 grams of fiber and .5 grams of protein. In terms of the major vitamins and minerals, it contains a solid amount of iron but not much else. So the basic nutritional facts are pretty pedestrian. If that's the case, why is turmeric getting so much hype?
The answers lies in curcumin, a powerful antioxidant found almost exclusively in turmeric. Much of the research into turmeric's health benefits focus on its curcumin content. When it comes to the purported benefits of turmeric, curcumin is key.
How much curcumin is in ground turmeric?
According to a 2006 study published in the journal Nutrition and Cancer, pure turmeric powder averages 3.14% curcumin by weight. So if you eat 100 grams of pure turmeric powder, you will consume about 3.14 grams of curcumin. A tablespoon of turmeric powder measures 17 grams, containing roughly .57 grams (or 570 mg) of curcumin. That's a solid amount, but downing tablespoons of ground turmeric powder can be unpleasant—which is why many people take turmeric in the form of a capsule supplement.
Now that we know about the importance of curcumin, let's check out the research.

Can Turmeric Help Reduce Inflammation?

Ground Turmeric


Inflammation is the body's natural response to injury, infection or disease. Its purpose is to protect the body and let it heal. But chronic inflammation can become a health risk. Many common conditions—such as asthma and arthritis—are classified as "inflammatory," and inflammation can contribute to more life-threatening diseases like cancer and cardiovascular disease. So if turmeric could help reduce inflammation, that would be an awesome benefit. But is it true?
RELATED: Three Powerful Health Benefits of Turmeric
The research says yes. Examine, an independent site that collates scientific research and disseminates information on supplementation and nutrition, points to five separate studies regarding curcumin's effects on inflammation before concluding that "there appears to be a decrease in disease states or conditions characterized by inflammation associated with curcumin ingestion" and that curcumin "does not appear to be too discriminatory in which inflammatory states it benefits."
The average age of the subjects varied widely among the studies, and curcumin was found to reduce inflammation related to a wide variety of conditions, including osteoarthritis, diabetic nephropathy and lichen planus (a skin disease).

Can Turmeric Change Body Composition?

 

Turmeric

Millions of Americans are overweight. And millions of Americans desire to change their bodies for the better. So the promise that turmeric can potentially aid in fat loss is certainly appealing. But does the research back it up?
Not quite. There currently isn't enough data to support the idea that turmeric has a significant effect on body composition. A 2009 animal study found that dietary curcumin could potentially inhibit the spread of fat tissue, but not  enough high-quality research is yet available to reach a conclusion on this topic.

Can Turmeric Be Used as a Pain Reliever?

 

Turmeric


One of turmeric's most interesting reported benefits is pain relief. Instead of popping a Tylenol, you could just down some turmeric. It's intriguing, sure. But is it true?
It looks likely. There haven't been a ton of studies on turmeric's role as a pain reliever, but what's available is encouraging. Examine writes, "there appear to be decreases in pain associated with curcumin at higher doses (400-500 mg) which extend to post-operative, arthritic and general pain symptoms. This does seem comparable to 2g of acetaminophen in potency."
Acetaminophen is the major active ingredient in Tylenol and many generic pain relievers, so that's a pretty impressive result.

Can Turmeric Help Battle or Even Prevent Forms of Cancer?

 

Turmeric


Perhaps the most intriguing purported benefit of turmeric is its ability to battle cancer. It sounds too good to be true, but a growing amount of research suggests that curcumin can help fight this all-too-common disease.
According to the University of Maryland Medical Center, "there has been a great deal of research on turmeric's anti-cancer properties, but results are still very preliminary. Evidence from test tube and animal studies suggests that curcumin may help prevent or treat several types of cancers, including prostate, breast, skin, and colon cancer. Tumeric's preventive effects may relate to its antioxidant properties, which protect cells from damage. More research is needed."
Yes, more research is needed, but early results are encouraging regarding curcumin's role in battling cancer.

Can Turmeric Help Prevent Heart Disease?

 

Turmeric


According to the CDC, one in every four deaths in the United States can be attributed to heart disease. Could turmeric help curb this massive public health issue?
RELATED: Heart-Healthy Foods for Athletes
It's too early to tell. Some animal studies have found that curcumin could help improve your cholesterol profile and thus reduce your risk of blocked arteries (which lead to heart attacks and stroke), but the same results have not yet been achieved in human studies. Turmeric could potentially help prevent heart disease, or it could have no discernible effect—we'll just have to wait for more research.

Can Turmeric Help Treat Depression?

Turmeric


According to the Anxiety Disorders Association of America, depression affects nearly 15 million Americans in any given year. Could turmeric help boost the mood of those suffering with depression?
Research has been sparse but encouraging. One study found that taking 500 mg of curcumin twice a day (roughly equivalent to two tablespoons of pure powdered turmeric) helped depressed subjects reduce their symptoms as well as Fluoxetine, a popular anti-depressant medication frequently marketed under the name "Prozac." However, no placebo group was used for comparison in the study.

Can Turmeric Make Me More Attractive?

 

Ground Turmeric


Turmeric's supposed benefits also include beautification: whiter teeth, clearer skin and thicker hair. They all sound great, but the only one supported by research is clearer skin.
RELATED: Just a Spoonful a Day of These 5 Foods Can Boost Your Health
Several studies have found that ground turmeric helps protect the skin from UV rays, reduce the appearance of dark spots, reduce acne, prevent wrinkles and help heal wounds. So the idea that turmeric can help improve the health and appearance of your skin certainly sounds valid.
However, claims like whiter teeth and thicker hair aren't backed by the same amount of research. It's possible that turmeric (more specifically, curcumin) could help confer those benefits, but the research is extremely limited at this point in time.

The Verdict

 

Turmeric


It's not unusual for the benefits of hip, trendy foods to get totally overblown. However, in the case of turmeric, a solid amount of research backs up many of its purported health benefits. More research is needed before concrete conclusions are reached, but even in areas where the research has been sparse—such as pain relief—early results have been encouraging. You shouldn't toss out the contents of your medicine cabinet in favor of turmeric, but it really does seem likely to have impressive capabilities.
There has yet to be a consensus on the best way to ingest turmeric and/or curcumin. The human body has been found capable of consuming 8 grams of curcumin a day without adverse affects, so overdosing shouldn't be a major concern. Whether you take it as a supplement or use it to spice up your food, you should strive to combine turmeric with a source of fat and/or black pepper. These greatly increase the absorption rate of curcumin, and many turmeric or curcumin supplements contain them.

Topics: DIET
 
Brandon Hall Brandon Hall - Brandon Hall is an Assistant Content Director for STACK. He graduated from Lafayette College, where he played football and graduated with a Bachelor's degree in English.

Wednesday, February 17, 2016

Humans and Neanderthals had sex a lot earlier than scientists thought

http://www.theverge.com/

Some humans may have left Africa over 100,000 years ago

(Hairymuseummatt / Dr.Mike Baxter)
An analysis of the genome of a Siberian Neanderthal, published today in Nature, reveals for the first time that humans contributed DNA to the Neanderthal genome about 100,000 years ago; that's 50,000 years earlier than the previous estimate. The finding points to an earlier departure from Africa for our human ancestors.
Between 1 and 7 percent of the Siberian Neanderthal’s genome was human — inherited from people who migrated out of Africa. That suggests humans and Neanderthals interbred several times. But it also alters our understanding of human history. Since Neanderthals didn’t make it to Africa, humans must have left about 50,000 years earlier than evolutionary biologists had previously estimated. And that's big news, says Sergi Castellano, an evolutionary biologist at the Max Planck Institute for Evolutionary Anthropology in Germany and a co-author of the study. This is "the first piece of genetic evidence" that some modern humans "were already out of Africa" 100,000 years ago, he says.
Humans left their mark on Neanderthals, too
Previous genetic analyses have revealed that humans interbred with Neanderthals less than 65,000 years ago, outside of Africa. As a result, Europeans and Asians inherited between 1 and 4 percent of their DNA from Neanderthals. And that DNA still has an effect on humans today; just last week scientists linked Neanderthal DNA to a wide range of human health conditions, including depression and nicotine addiction.
But until now, what researchers knew about Neanderthal-human interactions came from studying the flow of genes from Neanderthals to humans — and not the other way around. That's mostly because researchers didn't have the kinds of technologies or the appropriate Neanderthal DNA samples that would allow them to search in the opposite direction. This is the first time that scientists have been able to find evidence that humans left their genetic mark on Neanderthals as well, says Laurent Frantz, an evolutionary biologist at the University of Oxford who didn't work on the study.
A Siberian Neanderthal with human DNA
To arrive at these conclusions, Castellano and his team searched the complete genome of a Neanderthal discovered in a Siberian Cave in 2010. They found that certain regions of the Neanderthal's genome was closely related to those found in African human populations today. To estimate the timing of the interbreeding event, the researchers performed a statistical analyses based on the size and the clustering of the DNA fragments. This technique works because researchers know that when animals reproduce, their genetic material mixes with that of other animals; this causes individual DNA fragments belonging to one individual to break into smaller pieces as they're passed down through generations. In this particular case, the technique revealed that the Siberian Neanderthal's ancestors interbred with humans some 100,000 years ago.

neanderthal-dorsal-bone-bence-viola
Neanderthal toe bone (Bence Viola)
The researchers verified their findings by looking at the genome of a Denisovan — a member of an extinct human species that split off from Neanderthals some 380,000 years ago, after Neanderthals became a subspecies distinct from modern humans. Because Denisovans are more closely related to Neanderthals than they are to humans, their genomes can help scientists figure out the kinds of genetic mutations that are typical of these human subspecies. The analysis showed no evidence of the human DNA fragments in the Denisovan's genome, which suggests that these genetic elements were introduced in the Siberian Neanderthal's genome after Denisovans and Neanderthals evolved away from each other.
Castellano and his team also compared genetic material on chromosome 21 for the Siberia Neanderthal and two different populations of European Neanderthals. The scientists found no evidence of human integration in the European samples, which means that ancestors of the introduction of human DNA into the Siberia Neanderthal probably happened after the Siberian population branched off from the European Neanderthals,  around 110,00 years ago.
"This is a big milestone."
The study "doesn't change what we knew before; it's building on it," Frantz says. Instead, it gives scientists a better understanding of how many times human and Neanderthals met. "This is a big milestone," he says.
Sarah Tishkoff, an evolutionary biologist at University of Pennsylvania who didn't work on this study, agrees. "This is really exciting work because it changes what we thought about human evolutionary history." But she also says that the the comparison of chromosome 21 means that researchers could be missing signs of human DNA integration in the rest of the European genomes. In addition, the study doesn't actually reveal much about the interbreeding event itself. Even though the Neanderthal in the study was found in Siberia, the human-neanderthal interactions probably occurred further south, Tishkoff says. But where exactly those interactions happened is a mystery. The fate of these adventurous humans is also unclear, Frantz says. "The population is probably partly extinct, and partly integrated in many different populations across the world."
The study raises a ton of questions, but for now the findings suggest that what we thought we knew about humans and Neanderthals is just one tiny piece of the puzzle. "There could have been multiple [human] migrations coming out of Africa, and some groups just didn't make it," Tishkoff says. Research like this helps "paint a picture of what the ancestry was, not just of modern humans, but of Neanderthals; and that picture was more complex than we thought."

Tuesday, February 16, 2016

DNA rice breakthrough raises 'green revolution' hopes

AFP
Drawing on a massive bank of varieties stored in the Philippines and state-of-the-art Chinese technology, scientists recently completed the DNA sequencing of more than 3,000 types of rice
Los Baños (Philippines) (AFP) - Rice-growing techniques learned through thousands of years of trial and error are about to be turbocharged with DNA technology in a breakthrough hailed by scientists as a potential second "green revolution".
Over the next few years farmers are expected to have new genome sequencing technology at their disposal, helping to offset a myriad of problems that threaten to curtail production of the grain that feeds half of humanity.
Drawing on a massive bank of varieties stored in the Philippines and state-of-the-art Chinese technology, scientists recently completed the DNA sequencing of more than 3,000 of the world's most significant types of rice.
With the huge pool of data unlocked, rice breeders will soon be able to produce higher-yielding varieties much more quickly and under increasingly stressful conditions, scientists involved with the project told AFP.
Other potential new varieties being dreamt about are ones that are resistant to certain pests and diseases, or types that pack more nutrients and vitamins.
"This will be a big help to strengthen food security for rice eaters," said Kenneth McNally, an American biochemist at the Philippines-based International Rice Research Institute (IRRI).
Since rice was first domesticated thousands of years ago, farmers have improved yields through various planting techniques.
For the past century breeders have isolated traits, such as high yields and disease resistance, then developed them through cross breeding.
However, they did not know which genes controlled which traits, leaving much of the effort to lengthy guesswork.
The latest breakthroughs in molecular genetics promise to fast-track the process, eliminating much of the mystery, scientists involved in the project told AFP.
Better rice varieties can now be expected to be developed and passed on to farmers' hands in less than three years, compared with 12 without the guidance of DNA sequencing.
Genome sequencing involves decoding DNA, the hereditary material of all living cells and organisms. The process roughly compares with solving a giant jigsaw puzzle made up of billions of microscopic pieces.
A multinational team undertook the four-year project with the DNA decoding primarily in China by BGI, the world's biggest genome sequencing firm.
Leaf tissue from the samples, drawn mostly from IRRI's gene bank of 127,000 varieties were ground by McNally's team at its laboratory in Los Banos, near Manila's southern outskirts, before being shipped for sequencing.
A non-profit research outfit founded in 1960, IRRI works with governments to develop advanced varieties of the grain.
- Threats to rice -
Farmers and breeders will need the new DNA tools, which scientists take pains to say is not genetic modification, because of the increasingly stressful conditions for rice growing expected in the 21st Century.
While there will be many more millions to feed, there is expected to be less land available for planting as farms are converted for urban development, destroyed by rising sea levels or converted to other crops.
Rice-paddy destroying floods, drought and storms are also expected to worsen with climate change. Meanwhile, pests and diseases that evolve to resist herbicides and pesticides will be more difficult to kill.
And fresh water, vital for growing rice, is expected to become an increasingly scarce commodity in many parts of the world.
As scientists develop the tools necessary to harness the full advantages of the rice genome database, the hope is that new varieties can be developed to combat all those problems.
"Essentially, you will be able to design what properties you want in rice, in terms of the drought resistance, resistance to diseases, high yields, and others," said Russian bioanalytics expert and IRRI team member Nickolai Alexandrov.
- Food revolution -
Scientists behind the project hope it will lead to a second "green revolution".
The first began in the 1960s as the development of higher-yielding varieties of wheat and rice was credited with preventing massive global food shortages around the world.
That giant leap to producing more food involved the cross-breeding of unrelated varieties to produce new ones that grew faster and produced higher yields, mainly by being able to respond better to fertiliser.
But the massive gains of the earlier efforts, which earnt US geneticist Norman Borlaug the Nobel Peace Prize in 1970, have since reached a plateau.
Although the DNA breakthrough has generated much optimism, IRRI scientists caution it is not a magic bullet for all rice-growing problems, and believe that genetically modifying is also necessary.
They also warn that governments will still need to implement the right policies, such as in regards to land and water use.
One of the key priorities of IRRI is to pack more nutrients into rice, transforming it into a tool to fight ailments linked to inadequate diets in poor countries as well as lifestyle diseases in wealthier countries.
"We're interested to understand the nutritional value.... we're looking into the enrichment of micronutrients," Nese Sreenivasulu, the Indian head of the IRRI's grain quality and nutrition centre told AFP.
Nese believes Type-2 diabetes, which afflicts hundreds of millions of people, can be checked by breeding for particular varieties of rice which when cooked will release sugar into the bloodstream more slowly.
IRRI scientists are also hoping to breed rice varieties with a higher component of zinc, which prevents stunting and deaths from diarohea in rice-eating Southeast Asia.

Tuesday, February 9, 2016

New dinosaur species offers evolutionary clues

Reuters

By Jim Drury
Paleontologists say a 201-million-year-old dinosaur fossil found two years ago on a Welsh beach could offer vital clues to understanding the evolution from the late Triassic to the early Jurassic Period.
    Dracoraptor hanigani has been classified as a new species. It's one of the oldest Jurassic dinosaurs ever found, and among the most complete specimens from the time period.
    The early Jurassic period is crucial in the evolutionary history of dinosaurs. It followed an extinction event in the late Triassic era that wiped out more than half the species on Earth and may have created the subsequent global dominance of the dinosaurs, led by the likes of Tyrannosaurus rex and Velociraptor.
    According to Cindy Howells, palaeontology curator at the National Museum of Wales where the fossil is on display, "it's an important find in the early Jurassic because at that time dinosaurs were just starting to diversify. They'd only just evolved, but the continents were in such a position it was favorable, the warm climate, and this is just when we were getting that evolution of different types of dinosaurs meat-eaters were just starting out on the journey they made toward the Velociraptor and Tyrannosaurus that we have in the Cretaceous period. So this little dinosaur is (one of) the very first along the line that led to the Velociraptor."    
    Species which successfully crossed over into the Jurassic age are believed by experts to hold clues to the diversification of dinosaurs into the many species that existed in the middle Jurassic period, some of which are the ancestors of birds.
    Dracoraptor translates loosely as "dragon thief", while hanigani namechecks Rob and Nick Hanigan, the two fossil-hunting brothers who found the remains at Lavernock Point near the Welsh capital Cardiff.
    Forty percent of the animal was preserved, including its skull, claws, teeth and foot bones. Due to the body's symmetry this has enabled the virtual recreation of 80 percent of the Dracoraptor.
    "Because we've got so much of it we can fill in quite a lot of gaps in the evolution of this period and we can use it to compare with other dinosaurs that we've got in America and around the world and the comparison of its anatomy helps us understand how these dinosaurs moved, what they ate, how they lived."
    The creature was relatively small, around two meters long from head to tail. A poster in the museum shows it to be many times smaller than the Tyrannosaurus rex, although paleontologists believe it to be a juvenile of indistinct age. Dracoraptor had short arms and large hands.
    "This dinosaur was very small," said Howells. "It was an agile, meat eating creature with sharp teeth, sharp claws, able to move swiftly and grab its prey. We don't quite know what it would have eaten, but possibly small reptiles, small mammals, and possibly other dinosaurs as well. It was a bit like a medium sized dog, very slender, very long-tailed to help it balance as it moved."
    Dating the creature was possible because the remains were found above the layers containing Triassic conodont fossils. Geochemical analysis of carbon isotopes can also be used to establish the Jurassic age of these rocks.
    "We know this dinosaur is (was born) 200 million years ago, to within half a million years or so," said Howells. "The rocks down here we've been studying for quite a long time now and we can do direct comparisons with the ages of rocks in Austria, which is where the transition between the Triassic and the Jurassic boundaries is precisely located." 
    She added: "This dinosaur is really significant because we have very few meat-eating dinosaurs, (or) these Theropod dinosaurs from the very beginning of the Jurassic. This was a time just after a big extinction event had happened and the dinosaurs were just starting to diversify and expand in their range, so this is one of the first complete skeletons that we have from that age."
    Paul Barrett, of the Natural History Museum in London, told New Scientist the dracoraptor is "one of the best preserved meat-eating dinosaurs from the early part of the Jurassic Period - not only in Europe, but globally." Barrett believes its discovery will be crucial in unlocking understanding how dinosaurs evolved in the wake of the major extinctions.

Friday, February 5, 2016

Mystery invaders conquered Europe at the end of last ice age

https://www.newscientist.com

DNA was taken from ancient human bones, like this skull, from the Dolnte Vestonice burial site in the Czech Republic


DNA was taken from ancient human bones, like this skull, 
from the Dolnte Vestonice burial site in the Czech Republic

L. Lang
Europe went through a major population upheaval about 14,500 years ago, at the end of the last ice age, according to DNA from the bones of hunter-gatherers.
Ancient DNA studies published in the last five years have transformed what we know about the early peopling of Europe. The picture they paint is one in which successive waves of immigration wash over the continent, bringing in new people, new genes and new technologies.
These studies helped confirm that Europe’s early hunter-gatherers – who arrived about 40,000 years ago – were largely replaced by farmers arriving from the Middle East about 8000 years ago. These farmers then saw an influx of pastoralists from the Eurasian steppe about 4500 years ago, meaning modern Europe was shaped by three major population turnover events.

Waves of immigration

The latest study suggests things were even more complicated. About 14,500 years ago, when Europe was emerging from the last ice age, the hunter-gatherers who had endured the chilly conditions were largely replaced by a different population of hunter-gatherers.
Exactly where this new population came from is still unclear, but it seems likely that they came from warmer areas further south. “The main hypothesis would be glacial refugia in south-eastern Europe,” says Johannes Krause at the Max Planck Institute for the Science of Human History in Jena, Germany, who led the analysis.
As conditions improved, it was these southern hunter-gatherers who took advantage and migrated into central and northern Europe, he says – meaning there was a genetic discontinuity with the hunter-gatherer populations that had lived there earlier.


2nd_107773
Martin Frouz
His team analysed mitochondrial DNA extracted from 55 ancient Europeans, the oldest of whom lived 35,000 years ago – during the Pleistocene – and the youngest just 7000 years ago, during the Holocene. Previous studies focused largely on the Holocene, looking at human remains from the last 10,000 years.
“This is the first glimpse at Pleistocene population dynamics in Europe,” says Krause. “Little has been done on this older material, mostly due to lower abundance of material and lesser preservation due to age.”
“The population turnover after 14,500 years ago was completely unexpected,” says Iosif Lazaridis at the Harvard Medical School in Boston. “It seems that the hunter-gatherers of Europe braved the worst of the ice age during the last glacial maximum but were then replaced when the ice age had begun to subside.”

Europe’s unusual history

The picture is not yet clear, however, as the study only looked at mitochondrial DNA sequences, rather than the longer nuclear DNA of other studies. “Mitochondrial DNA tells only part of the story of a population,” says Lazaridis. It is important to try to extract nuclear sequences from the Pleistocene-aged skeletons to find out more about this earlier population turnover, he says.
The work also may solve a long-standing mystery of why a certain genetic signature is missing in people of European ancestry. All people today are members of one of a relatively small number of distinct groups based on their mitochondrial DNA, which is passed down the maternal line. The distribution of people in each group gives us a sense of how humans spread across the world in prehistory.
It always seemed that Europe had a very unusual history of colonisation because one major haplogroup – the M clade – is almost entirely missing, despite being very common across Asia and even found in Native Americans. Instead, another major haplogroup – the N clade – is most common.
“Some authors had argued that the M and N haplogroups represented two different dispersal events from Africa,” says Toomas Kivisild at the University of Cambridge.
But Krause and his colleagues found that the M clade might actually have been common in Europe before the population turnover 14,500 years ago: three of the 18 most ancient humans they studied belonged to the M clade.
This suggests that the initial colonisation of Europe and Asia may have involved the same ancient population – and that the M group was actually lost in Europe much later, perhaps connected in some way to the mystery upheavals 14,500 years ago.
Journal reference: Current Biology, DOI: 10.1016/j.cub.2016.01.037
Read more: The three ancestral tribes that founded Western civilisation

 http://arstechnica.com/

Scientific Method / Science & Exploration


There was a massive population crash in Europe over 14,500 years ago

New evidence shows a whole group of Europeans vanished, replaced by people of unknown origins.


Europe wasn't a very hospitable place fifteen millennia ago. The westernmost landmass of the Eurasian continent had endured a long ice age, with glaciers stretching across northern Europe and into the region we now call Germany. But suddenly, about 14,500 years ago, things started to warm up quickly. The glaciers melted so fast around the globe that they caused sea levels to rise 52 feet in just 500 years. Meanwhile, the environment was in chaos, with wildlife trying vainly to adjust to the rapid fluctuations in temperature. Humans weren't immune to the changes, either.
A new, comprehensive analysis of ancient European DNA published today in Current Biology magazine by an international group of researchers reveals that this period also witnessed a dramatic shift in the human populations of Europe. Bloodlines of hunter-gatherers that had flourished for thousands of years disappeared, replaced with a new group of hunter-gatherers of unknown origin.
Researchers discovered this catastrophic population meltdown by sequencing the mitochondrial DNA of 35 people who lived throughout Europe between 35 and 7 thousand years ago. Mitochondrial DNA is a tiny amount of genetic material that's inherited virtually unchanged via the maternal line, and thus it serves as a good proxy for relatedness over time. Two people from the same maternal stock share almost the same mitochondrial DNA, even if separated by thousands of years, because this kind of DNA evolves very slowly.
It's long been known that two such related groups, called M clade and N clade, poured out of Africa and across the Eurasian continent about 55 thousand years ago. Some of these people wandered so far that they even made it to Australia, eventually. And yet something rather odd happened to the people of Europe. Only members of the N clade survived into the present day, while Asia, Australia, and the Americas are full of the offspring of both N and M. Until the new study in Current Biology, scientists believed that the most likely explanation was that roughly 45 thousand years ago, Europe was colonized solely by the N clade, while both clades settled elsewhere around the world.
But thanks to sequencing the mitochondrial DNA in those 35 ancient people, the researchers uncovered something previously unknown. There were, in fact, people from the M clade alive in Europe as recently as 25 thousand years ago. But something happened to wipe them out during the cold, dry glacial maximum that gripped the world between 25 and 14.5 thousand years ago.

Enlarge / In this image, you can see the clades of the people
 who the team sequenced, and how they fared over time. The
 R and U clades are all descended from the N clade. Note that
 M is present until 25 thousand years ago, when the ice age begins.
Current Biology
There are obvious reasons why Europeans might have suffered a population bottleneck during the ice age, or the Last Glacial Maximum. Food was scarce, and once-fecund habitats became unlivable. Groups that once roamed the wide-open fields of Europe retreated into small refuges, separated by walls of ice or frozen drought wastelends created when glaciation locks up atmospheric water. The researchers believe that the M clade, whose members were found far to the north, may have slowly died out during that period. After the glaciers retreated, the survivors were replaced by a new N-related population from elsewhere on the continent.
Write the researchers:
The potential impact of climatic events on the demography, and thus the genetic diversity of early Europeans, has previously been difficult to quantify, but it likely had consequences for the relative components of ancient ancestry in modern-day populations. Our demographic modeling reveals a dynamic history of hunter-gatherers, including a previously unknown major population shift during the Late Glacial interstadial (the BøllingAllerød, 14.5 ka). Under our best-fitting model, the small initial founder population of Europe slowly grows up until 25 ka and survives with smaller size in LGM [Last Glacial Maximum] climatic refugia (25–19.5 ka) before re-expanding as the ice sheets retract. Although this model supports population continuity from pre- to post-LGM, the genetic bottleneck is consistent with the apparent loss of hg M in the post-LGM. Globally, the early warming phases of the Late Glacial are strongly associated with substantial demographic changes, including extinctions of several megafaunal species and the first expansion of modern humans into the Americas. In European hunter-gatherers, our model best explains this period of upheaval as a replacement of the post-LGM maternal population by one from another source.
Essentially, an entire genetic line in Europe was wiped out by climate change. You might say that today's European population still bears the scars of an ancient ice age in its mitochondrial DNA.
Current Biology, 2016. DOI: 10.1016/j.cub.2016.01.037.

Why Did Ancient Europeans Just Disappear 14,500 Years Ago?

LiveScience.com
Why Did Ancient Europeans Just Disappear 14,500 Years Ago? 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 The skull of a man who lived between 36,200 
and 38,700 years ago in Kostenki in western Russia.
 
Some of Europe's earliest inhabitants mysteriously vanished toward the end of the last ice age and were largely replaced by others, a new genetic analysis finds.
The finds come from an analysis of dozens of ancient fossil remains collected across Europe.
The genetic turnover was likely the result of a rapidly changing climate, which the earlier inhabitants of Europe couldn't adapt to quickly enough, said the study's co-author, Cosimo Posth, an archaeogenetics doctoral candidate at the University of Tübingen in Germany.
 [Top 10 Mysteries of the First Humans]
The temperature change around that time was "enormous compared to the climactic changes that are happening in our century," Posth told Live Science. "You have to imagine that also the environment changed pretty drastically."
A twisted family tree
Europe has a long and tangled genetic legacy. Genetic studies have revealed that the first modern humans who poured out of Africa, somewhere between 40,000 and 70,000 years ago, soon got busy mating with local Neanderthals. At the beginning of the agricultural revolution, between 10,000 and 12,000 years ago, farmers from the Middle East swept across Europe, gradually replacing the native hunter-gatherers. Around 5,000 years ago, nomadic horsemen called the Yamnaya emerged from the steppes of Ukraine and intermingled with the native population. In addition, another lost group of ancient Europeans mysteriously vanished about 4,500 years ago, a 2013 study in the journal Nature Communications found.
But relatively little was known about human occupation of Europe between the first out-of-Africa event and the end of the last ice age, around 11,000 years ago. During some of that time, the vast Weichselian Ice Sheet covered much of northern Europe, while glaciers in the Pyrenees and the Alps blocked east-west passage across the continent.
Lost lineages
To get a better picture of Europe's genetic legacy during this cold snap, Posth and his colleagues analyzed mitochondrial DNA — genetic material passed on from mother to daughter — from the remains of 55 different human fossils between 35,000 and 7,000 years old, coming from across the continent, from Spain to Russia. Based on mutations, or changes in this mitochondrial DNA, geneticists have identified large genetic populations, or super-haplogroups, that share distant common ancestors.
"Basically all modern humans outside of Africa, from Europe to the tip of South America, they belong to these two super-haplogroups that are M or N," Posth said. Nowadays, everyone of European descent has the N mitochondrial haplotype, while the M subtype is common throughout Asia and Australasia.
The team found that in ancient people, the M haplogroup predominated until about 14,500 years ago, when it mysteriously and suddenly vanished. The M haplotype carried by the ancient Europeans, which no longer exists in Europe today, shared a common ancestor with modern-day M-haplotype carriers around 50,000 years ago.
The genetic analysis also revealed that Europeans, Asians and Australasians may descend from a group of humans who emerged from Africa and rapidly dispersed throughout the continent no earlier than 55,000 years ago, the researchers reported Feb. 4 in the journal Current Biology.
Time of upheaval
The team suspects this upheaval may have been caused by wild climate swings.
At the peak of the ice age, around 19,000 to 22,000 years ago, people hunkered down in climactic "refugia," or ice-free regions of Europe, such as modern-day Spain, the Balkans and southern Italy, Posth said. While holdouts survived in a few places farther north, their populations shrank dramatically.
Then around 14,500 years ago, the temperature spiked significantly, the tundra gave way to forest and many iconic beasts, such as woolly mammoths and saber-toothed tigers, disappeared from Eurasia, he said.
For whatever reason, the already small populations belonging to the M haplogroup were not able to survive these changes in their habitat, and a new population, carrying the N subtype, replaced the M-group ice-age holdout, the researchers speculate.
Exactly where these replacements came from is still a mystery. But one possibility is that the newer generation of Europeans hailed from southern European refugia that were connected to the rest of Europe once the ice receded, Posth speculated. Emigrants from southern Europe would also have been better adapted to the warming conditions in central Europe, he added.

 




















 

 

 

 


Cavemen From 400,000 Years Ago Ate Better Meals Than You Do

Mic

Neanderthal chefs had a fine-dining streak.
Tel Aviv University archaeologists discovered burn-marked 400,000-year-old tortoise shells and bones in Israel's Qesem Cave, a site that was occupied by humans hundreds of thousands of years ago. The team, lead by archaeologist Ran Barkai, published a paper indicating the shells were cut open in a way consistent with "cooking in the shell, defleshing and direct percussion to access the visceral content," which is the academic-paper way to say, "cut 'em and cook 'em."
But tortoises aren't big enough to support an entire diet, unless Ug and Gork were spending the whole day shucking tortoise shells and talking about life. Therefore, Barkai deduced, they must have been part of a larger meal, along with what prehistoric dental records show to be plenty of vegetables too.
"Now we know they ate tortoises in a rather sophisticated way," Barkai said, according to CBC News. "It would have been a supplement — an appetizer, dessert or a side dish — to the meat and fat from large animals."

Cavemen From 400,000 Years Ago Ate Better Meals Than You Do
Source: Giphy
Around this time, we know Neanderthals made wooden spears to hunt and kill large animals, in some cases horses. The tortoise discovery is a eureka moment in Barkai's ongoing research into how hominids filled the gaps in diet when there was nothing huge to kill.
But there's an unfortunate twist: Thanks to Barkai's findings, we now know early man occasionally had a meat appetizer before the meat main course, which is a bummer, because it only reinforces believers in the questionable paleo diet, which has people eat little else but seeds and meat to mimic paleolithic man.

40 million years before butterflies existed, this creature evolved with strikingly similar looks

 https://www.washingtonpost.com/

Speaking of Science
Before butterflies, there were Kalligrammatid lacewings — winged insects that took butterfly-like form at least 40 million years before the modern bugs first came on the scene. But the remarkably butterflyesque species Oregramma illecebrosa, described in a study published Wednesday in Proceedings of the Royal Society B, isn't a butterfly ancestor: Other members of its lineage went on to become entirely different sorts of insects. Instead, this striking similarity is a case of convergent evolution — the same shapes, patterns and perhaps even behaviors came about twice, totally independently.
The findings come thanks to some especially well-preserved fossils found in northeastern China, which allowed researchers to study the ancient insects more closely than ever before.
"They've been known for about 100 years, but in the 1960s there were some specimens that made people say, gosh, these really look like butterflies," Smithsonian paleoecologist Conrad Labandeira, lead author on the study, told The Washington Post. "But we knew they were unrelated. That's where it stood for some 55 years."
But once Labandeira and his team — an international collaboration of scientists — got a hold of the Chinese fossils, things got much more interesting. The resemblance is so strong that even experts were fooled at a distance: Labandeira recalls a colleague from the entomology department assuming the fossil on the table was a butterfly from 20 feet away.
"When I told him to come closer, and he looked again, his jaw dropped," Labandeira said.
One of the more remarkable similarities is superficial in nature: The spots seen on the Oregramma illecebrosa fossils are nearly identical to patterns found on owl butterflies today. These so-called eye spots mimic the peepers of a large bird, scaring off predators that might otherwise make a quick snack of a delicate butterfly.
It's thought that Oregramma illecebrosa last shared a common ancestor with modern butterflies more than 320 million years ago. The fact that two quite unrelated insects developed these markings millions of years apart from one another is a perfect example of convergent evolutionOregramma illecebrosa might not have shared space with owls, but plenty of big-eyed creatures — perhaps even dinosaurs, the prominent predators of the Jurassic period — could have served as inspiration for the markings. An Oregramma illecebrosa would have had a better chance of surviving dino dinnertime if it could pass itself off as a bigger animal, and over time — as faux-eyed insects continued to breed more successfully than those without the markings — the patterns would become more complex.
Then, millions of years later, an unrelated group of insects did the exact same thing. What worked well in the Jurassic still works well today.
But there are signs that these ancient bugs shared behavioral traits with modern butterflies, too: They had modified hairs on their legs for collecting pollen, just as modern butterflies do. And they even had long proboscises, which modern butterflies use to suck nectar from flowers — even though flowering plants didn't exist at the time. Instead, Oregramma illecebrosa and its ilk would have gathered dry and liquid pollen from primitive, non-flowering plants.
This is another case of convergent evolution, Labandeira explained. Other studies have found that multiple groups of insects had these long mouth-parts before flowers existed, so they must have evolved specifically to suck the liquids of plants that have long gone extinct. Then, when flowers became ecologically dominant, the whole system was reinvented.
"It’s kind of like a baseball team," Labandeira said. "The positions are the same, but the players are changed. It was a different world that these insects were evolving in. So they’re serving very similar roles, but they’re completely different."