Modern lizards unchanged from ancient forebears preserved in amber

Lizards preserved in amber show little change in 20 million years. [Credit: Ettore Morone]

Lizards preserved in amber show little change in 20 million years. [Credit: Ettore Morone]

Scientists have been amazed to find that a group of lizards, preserved in amber for 20 million years, are identical to modern ones.

"These fossils were really surprising because of how much detail they contained, allowing us to see how these lizards would have looked in real life," the study's lead author Dr Emma Sherratt of the University of New England in Australia, told reporters.

The anolis lizards from the island of Hispaniola were preserved in remarkable detail, even down to their colour.

"Most of ours had full skeletons, and details of the skin were impressed on the amber, providing very detailed images of tiny scales on the body and on the sticky toe pads," she told the ABC.

"You could have taken a lizard today, embedded it resin and it would have looked like one of these creatures. That's how realistic and modern they look."

DNA studies show that the 400 species of anolis lizards across the islands of the Caribbean began colonising the region about 40 million years ago, and quickly adapted to most habitats, with their body shapes, leg length, and the scales on their toe pads adapting to suit each niche.

Using x-ray microcomputer tomography to produce three dimensional reconstructions of the fossils inside their amber cocoons, the researchers showed that the diversity of lizards that resulted 20 million years ago is the same seen today.

"Given we see the same range of morphological features this means the community of lizards has remained unchanged all this time," says Sherratt.

The research was reported in Proceedings of the National Academy of Sciences.



Curiosity rover puzzles over unusual Martian bedrock

A rock fragment dubbed "Lamoose" has unusually high concentrations of silica. The high silica was first detected in the area by the Chemistry & Camera (ChemCam) laser spectrometer. This rock was targeted for follow-up study by the MAHLI and the arm-mounted Alpha Particle X-ray Spectrometer (APXS). (click to expand) [Credits: NASA/JPL-Caltech/MSSS]


NASA's Curiosity Mars rover has found bedrock with surprisingly high levels of silica, something it has not before found in its three years on the red Planet's surface.

Silica, containing silicon and oxygen, is commonly found on Earth as quartz.

This area of the discovery lies on lower Mount Sharp.

"One never knows what to expect on Mars, but the ... target was interesting enough to go back and investigate," said Roger Wiens, the principal investigator of the ChemCam instrument, which detects chemical compositions in nearby terrain. 

A rock outcrop dubbed "Missoula," near Marias Pass on Mars, is seen in this image mosaic taken by the Mars Hand Lens Imager on NASA's Curiosity rover. Pale mudstone (bottom of outcrop) meets coarser sandstone (top) in this geological contact zone, which has piqued the interest of Mars scientists. [Credits: NASA/JPL-Caltech/MSSS]

Before the silica discovery, Curiosity was studying an outcrop where a pale mudstone meets darker sandstone.

"We found an outcrop named Missoula where the two rock types came together, but it was quite small and close to the ground. We used the robotic arm to capture a dog's-eye view with the MAHLI (Mars Hand Lens Imager) camera, getting our nose right in there," said Ashwin Vasavada, the mission's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

NASA orbiter prepares to greet new Mars lander at Red Planet

An artist's concept shows NASA's Mars Reconnaissance Orbiter mission over Mars [Credits: NASA/JPL-Caltech]

NASA's Mars Reconnaissance Orbiter (MRO) will today start preparations for the arrival of the next Mars lander, InSight, next year.

A planned 77-second firing of six intermediate-size thrusters later today will adjust the orbit timing of the spacecraft so it will be in position to receive radio transmissions from InSight as the newcomer descends through the Martian atmosphere and touches down on 28 September 2016. 

"Without making this orbit change manoeuvre, Mars Reconnaissance Orbiter would be unable to hear from InSight during the landing, but this will put us in the right place at the right time," said MRO Project Manager Dan Johnston of NASA's Jet Propulsion Laboratory, Pasadena, California.

The orbiter will record InSight's transmissions for later playback to Earth as a record of each event during the critical minutes of InSight's arrival at Mars, just as MRO did for the landings of NASA's Curiosity Mars rover three years ago, and NASA's Phoenix Mars lander in 2008.

InSight will examine the deep interior of Mars for clues about the formation and early evolution of all rocky planets, including Earth.

NASA images from one of the world's hottest volcano regions

[Credit: NASA]

A photograph, taken by an astronaut onboard the International Space Station, highlights the Kamchatka Peninsula in far eastern Russia, one of the most active volcanic regions on Earth.

The three largest volcanoes visible at image centre are Kliuchevskoy, Bezymianny, and Ushkovsky (see below for annotated image).

Klyuchevskoy is the most active volcano, with geologic, historical, and observational data indicating no major quiet periods since the volcano formed approximately 6,000 years ago. A thin ash and steam plume extends to the east-southeast from the summit of Klyuchevskoy, typical of activity reported at the volcano from early May 2015, when the photo was taken. The flanks of Klyuchevskoy are also covered with dark ash deposits, in contrast to the snow-covered flanks of both Bezymianny and Ushkovsky.

The Kamchatka Peninsula has more than 300 identified volcanoes, with 29 considered active, as well as hot springs, and geysers as a result of subduction of the Pacific oceanic plate beneath the overriding Eurasia continental plate.

The NASA Earth Observatory has more information.

[Credit: NASA]

Leading scientists urge a ban on killer robots

[Credit: Colin Anderson/Getty Images]

[Credit: Colin Anderson/Getty Images]

More than 1,000 of the leading researchers in artificial intelligence (AI) and robotics have published an open letter calling for a ban on offensive autonomous weapons, so-called “killer robots”.

SpaceX and Tesla CEO Elon Musk, physicist Stephen Hawking, Apple co-founder Steve Wozniak and Skype co-founder Jaan Talinn have joined forces to warn of a new arms race.

"If any major military power pushes ahead with AI weapon development, a global arms race is virtually inevitable, and the endpoint of this technological trajectory is obvious: autonomous weapons will become the Kalashnikovs of tomorrow," the letter warns.

Musk, Hawking and Wozniak have all warned about the dangers of AI, with Musk saying it was artificial intelligence is our biggest existential threat. Bill Gates joined the chorus of concern recently, saying he didn't understand why some people are happy with the develop of AI.

Toby Walsh, one of the signatories to the letter, writing for The Conversation, said that the time to acts against weaponising AI systems was now.

"We can get it right at this early stage," he writes, "or we can stand idly by and witness the birth of a new era of warfare. Frankly, that’s not something many scientists in this field want to see."

You can read the Cosmos special issue on the rise of robots and AI here.

The following is the entire text of the open letter:

Autonomous weapons select and engage targets without human intervention. They might include, for example, armed quadcopters that can search for and eliminate people meeting certain pre-defined criteria, but do not include cruise missiles or remotely piloted drones for which humans make all targeting decisions. Artificial Intelligence (AI) technology has reached a point where the deployment of such systems is – practically if not legally – feasible within years, not decades, and the stakes are high: autonomous weapons have been described as the third revolution in warfare, after gunpowder and nuclear arms.
Many arguments have been made for and against autonomous weapons, for example that replacing human soldiers by machines is good by reducing casualties for the owner but bad by thereby lowering the threshold for going to battle. The key question for humanity today is whether to start a global AI arms race or to prevent it from starting. If any major military power pushes ahead with AI weapon development, a global arms race is virtually inevitable, and the endpoint of this technological trajectory is obvious: autonomous weapons will become the Kalashnikovs of tomorrow. Unlike nuclear weapons, they require no costly or hard-to-obtain raw materials, so they will become ubiquitous and cheap for all significant military powers to mass-produce. It will only be a matter of time until they appear on the black market and in the hands of terrorists, dictators wishing to better control their populace, warlords wishing to perpetrate ethnic cleansing, etc. Autonomous weapons are ideal for tasks such as assassinations, destabilizing nations, subduing populations and selectively killing a particular ethnic group. We therefore believe that a military AI arms race would not be beneficial for humanity. There are many ways in which AI can make battlefields safer for humans, especially civilians, without creating new tools for killing people.
Just as most chemists and biologists have no interest in building chemical or biological weapons, most AI researchers have no interest in building AI weapons — and do not want others to tarnish their field by doing so, potentially creating a major public backlash against AI that curtails its future societal benefits. Indeed, chemists and biologists have broadly supported international agreements that have successfully prohibited chemical and biological weapons, just as most physicists supported the treaties banning space-based nuclear weapons and blinding laser weapons.
In summary, we believe that AI has great potential to benefit humanity in many ways, and that the goal of the field should be to do so. Starting a military AI arms race is a bad idea, and should be prevented by a ban on offensive autonomous weapons beyond meaningful human control.

Two images of Pluto reveal more of dwarf planet's composition

[Credit: NASA/JHUAPL/SwRI]

[Credit: NASA/JHUAPL/SwRI]

The latest images released by NASA of Pluto, taken from the New Horizons spacecraft, provide two interesting views of the planet.

The first image (above top) uses enhanced colour to display differences in the composition and texture of Pluto’s surface.

It paints a new and surprising portrait of the dwarf planet. The “heart of the heart,” Sputnik Planum, is suggestive of a source region of ices. The two bluish-white “lobes” that extend to the southwest and northeast of the “heart” may represent exotic ices being transported away from Sputnik Planum. 

The second image, (above, bottom) shows the dwarf planet in true colour.

The images are the result of combining four images from New Horizons’ Long Range Reconnaissance Imager (LORRI) with colour data from the Ralph instrument. The images, taken when the spacecraft was 450,000 kilometres away from the planet.

We have seen the view before – it was taken on 13 July just before New Horizons' closest approach on 14 July – but this image is twice as sharp, showing features as small as 2.2 kilometres wide.

Note, the lower right edge of Pluto in this view currently lacks high-resolution colour coverage.

Evidence of plant cultivation 11,000 years earlier than known agriculture

Dr. Dani Nadel, Head of the Department of Archaeology, at the University of Haifa summarises the excavations at Ohalo II, a uniquely well-preserved 23,000 year-old fisher-hunter-gatherer's camp on the shore of the Sea of Galilee. 

The site of a 23,000-year-old camp of hunter gatherers on the shores of the Sea of Gallilee in Israel suggest that wheat was being cultivated there 11,000 years earlier than previous evidence of organised agriculture.

Archaeologists, botanists, and ecologists from Bar-Ilan University, Haifa University, Tel Aviv University, and Harvard University published the findings this week in the journal PLOS One.

They base their conclusions on a higher-than-usual presence at the site of domestic-type, rather than wild-type, wheat and barley; a high concentration of proto-weeds - plants of the type known to flourish in fields planted with domesticated crops; and an analysis of the tools found at the site that reveals blades used for cutting and harvesting cereal plants.

The site, known as Ohalo II, nine kilometres south of the modern city of Tiberias, was discovered in 1989 when the level of the lake plummeted.

It was then excavated for six seasons, exposing six brush hut dwellings, a human grave, copious and well-preserved remains of both animal and plant foods, beads from the Mediterranean Sea, as well as evidence of flint tool manufacture and use.

According to the study's lead researcher, Ehud Weiss of Bar-Ilan University, the study represents the earliest example of small-scale cultivation found anywhere in the world.

"The plant remains from the site were unusually well-preserved because of being charred and then covered by sediment and water which sealed them in low-oxygen conditions," Weiss explains.

"Due to this, it was possible to recover an extensive amount of information on the site and its inhabitants - which made this a uniquely preserved site, and therefore one of the best archaeological examples worldwide of hunter-gatherers' way of life. Here we see evidence of repeated sowing and harvesting of later domesticated cereals."

Some 150,000 plant remains show that the site's residents gathered more than 140 different plant species from the surrounding environment.

Among these, Weiss's team identified edible cereals - such as wild emmer, wild barley, and wild oats. These cereals were mixed with 13 species of "proto-weeds" - ancient ancestors of the current weeds known to flourish in cultivated, single-crop fields - indicating that they grew and were subsequently unintentionally gathered together.

A grinding slab set on a brush hut floor provided samples of microscopic cereal starch granules show that cereal grains were processed there.

More importantly the grains showed signs of being domesticated rather than wild.

"The ears of cereals like wheat and barley - in their wild form - are built from separate units that break off and are easily dispersed, allowing the seeds to reach the ground, germinate, and grow into a new plant without any human intervention," Weiss says.

"When humans cultivate these grains over a number of successive seasons, however, a change occurs. They develop a rough scar that locks the seed dispersal units together. Such plants cannot sow themselves. This is the hallmark of domesticated, rather than wild-type plants."

Four-legged snake sheds light on reptile's evolution

The legs on the Tetrapodophis amplectus fossil have led to a rethink about the evolution of some snakes. [Credit: Dave Martill, University of Portsmouth]

The legs on the Tetrapodophis amplectus fossil have led to a rethink about the evolution of some snakes. [Credit: Dave Martill, University of Portsmouth]

The discovery of a four-legged fossil of a snake suggests it may have evolved as a burrowing animal rather than a marine creature, scientists say.

The fossil, found in the Crato Formation in  northeastern Brazil, is of the newly discovered species Tetrapodophis amplectus. It lived during the Early Cretaceous 146 to 100 million years ago.

While the animal has many classic snake features, such as a short snout, long braincase, elongated body, scales, fanged teeth and a flexible jaw to swallow large prey, its four legs are a dramatic departure.

Scientists believe the limbs were not used for locomotion, however, and were instead used for grasping.

The authors of a study, reported in Science, base their assumption on the shorter exterior digits and lengthened second digit of the reptile's limbs.

Nevertheless, the fossil shows the typical vertebrae structure seen in modern-day snakes that allows for the extreme flexibility required to constrict prey.

But it lacks the long, laterally compressed tail typically found in aquatic animals, further suggesting that snakes did not evolve from marine ancestors. 

Dr Dave Martill, from the University of Portsmouth, found the fossil in a German museum collection.

"The fossil was part of a larger exhibition of fossils from the Cretaceous period. It was clear that no-one had appreciated its importance, but when I saw it I knew it was an incredibly significant specimen," he told reporters.

 

NASA Space Launch System on track for manned Mars mission

An artist's concept of the Space Launch System. [Credit: NASA/MSFC].

A final critical design review of NASA's Space Launch System has given it top marks, with everything on track for manned missions to the asteroid belt and Mars.

The SLS will be the most powerful rocket ever built and is designed to launch astronauts in the agency’s Orion spacecraft.

"Now that we've completed our review, we will brief NASA leadership, along with the independent review team, about the results and readiness to proceed to the next phase. After that step is complete, we'll move on to design certification," said Todd May, SLS program manager at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

"Critical design review represents a major commitment by the agency to human exploration, and through these reviews, we ensure the SLS design is on track to being a safe, sustainable and evolvable launch vehicle that will meet the agency's goals and missions.

"It's an exciting time for NASA and our nation as we prepare to go to places in deep space that we've never been before."

The critical design review is for the first of three configurations planned for SLS, referred to as SLS Block 1. It will stand 322 feet tall, provide 8.4 million pounds of thrust at liftoff, weigh 5.5 million pounds and carry 70 metric tons or 154,000 pounds of payload, equivalent to approximately 77 one-ton pickup trucks’ worth of cargo. Its first mission - Exploration Mission-1 - will launch an uncrewed Orion spacecraft to demonstrate the integrated system performance of the SLS rocket and Orion spacecraft before a crewed flight.

Kepler spies most Earth-like planet yet

This artist's concept depicts one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of star that is similar to our Sun. [Credits: NASA Ames/JPL-Caltech/T. Pyle].

 

Astronomers have found a close cousin of the Earth – a rocky planet circling its star in the "Goldilocks zone" where it is not too hot nor too cold to support liquid water, NASA says.

What's more the planet's star looks similar to our Sun, albeit at 6 billion years, a 1.5-billion-year older version.

The planet has been named Kepler 452b and is 1,400 light years away. It was detected by NASA's Kepler Space Telescope, which has been hunting for planets similar to the Earth since 2009.

Its similarity to Earth, combined with the age of the star, may give scientists some insights into what lies in store for our planet as an ageing Sun heats up a billion years from now, with massive heating leading to lakes and oceans evaporating. 

"If Kepler 452b is indeed a rocky planet, its location vis-a-vis its star could mean that it is just entering a runaway greenhouse phase of its climate history," said Doug Caldwell, a Search for Extraterrestrial Intelligence (SETI) Institute scientist working on the Kepler mission, told ABC news.

The Kepler mission launched in 2009 to search for exoplanets, which are planets outside our solar system, particularly those about the size of Earth or smaller.

NASA's latest catalogue of exoplanet candidates consists of 4,675 discovered by the telescope.

This size and scale of the Kepler-452 system compared alongside the Kepler-186 system and our solar system. Kepler-186 is a miniature solar system that would fit entirely inside the orbit of Mercury. The habitable zone of Kepler-186 is very small compared to that of Kepler-452 or the sun because it is a much smaller, cooler star. The size and extent of the habitable zone of Kepler-452 is nearly the same as that of the sun, but is slightly bigger because Kepler-452 is somewhat older, bigger and brighter. [Credits: NASA/JPL-CalTech/R. Hurt]

Kepler-452b is 60% larger in diameter than Earth. Scientists are yet to determine its mass and composition but previous research suggests that a planet its size should be rocky. Its orbit of 385 days is similar to an Earth-year. 

“We can think of Kepler-452b as an older, bigger cousin to Earth, providing an opportunity to understand and reflect upon Earth’s evolving environment," said Jon Jenkins, Kepler data analysis lead at NASA's Ames Research Center in Moffett Field, California, who led the team that discovered Kepler-452b.

"It’s awe-inspiring to consider that this planet has spent 6 billion years in the habitable zone of its star; longer than Earth. That’s substantial opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet.”

First images of nano particles that could be used to fight cancer

Scientists have developed a technique to capture 3D images of the structures of nanocrystals – tiny particles that could be used to fight cancer, collect renewable energy and mitigate pollution. 

Metallic nanoparticles are measured in nanometres (a nanometre is one millionth of a millimetre), so small they can't be seen, making it difficult to know how they work.

All that changes with the new technique explained in Science by Associate Professor Hans Elmlund from Monash University and his collaborators from Princeton, Boston and Harvard Universities.

The method is called “3D Structure Identification of Nanoparticles by Graphene Liquid Cell EM (SINGLE)” and it exceeds previous techniques by combining three recently developed components. 

The first is a graphene liquid cell, a bag one molecule thick that can hold liquid inside it while being exposed to the ultra high vacuum of the electron microscope column. The second is a direct electron detector, which is even more sensitive than traditional camera film and can be used to capture movies of the nanoparticles as they spin around in solution. Finally, a 3D modeling approach known as PRIME allows use of the movies to create three-dimensional computer models of individual nanoparticles. 

The video above shows the structure of two platinum nanoparticles, which have never been seen in such detail before.