Archaeologists working in two Italian caves have discovered some of the earliest known examples of ancient humans using an adhesive on their stone tools -- an important technological advance called "hafting."
The new study, which included CU Boulder's Paola Villa, shows that Neanderthals living in Europe from about 55 to 40 thousand years ago traveled away from their caves to collect resin from pine trees. They then used that sticky substance to glue stone tools to handles made out of wood or bone.
The findings add to a growing body of evidence that suggests that these cousins of Homo sapiens were more clever than some have made them out to be.
"We continue to find evidence that the Neanderthals were not inferior primitives but were quite capable of doing things that have traditionally only been attributed to modern humans," said Villa, corresponding author of the new study and an adjoint curator at the CU Museum of Natural History.
That insight, she added, came from a chance discovery from Grotta del Fossellone and Grotta di Sant'Agostino, a pair of caves near the beaches of what is now Italy's west coast.
Those caves were home to Neanderthals who lived in Europe during the Middle Paleolithic period, thousands of years before Homo sapiens set foot on the continent. Archaeologists have uncovered more than 1,000 stone tools from the two sites, including pieces of flint that measured not much more than an inch or two from end to end.
In a recent study of the tools, Villa and her colleagues noticed a strange residue on just a handful of the flints -- bits of what appeared to be organic material.
"Sometimes that material is just inorganic sediment, and sometimes it's the traces of the adhesive used to keep the tool in its socket" Villa said.
To find out, study lead author Ilaria Degano at the University of Pisa conducted a chemical analysis of 10 flints using a technique called gas chromatography/mass spectrometry. The tests showed that the stone tools had been coated with resin from local pine trees. In one case, that resin had also been mixed with beeswax.
Villa explained that the Italian Neanderthals didn't just resort to their bare hands to use stone tools. In at least some cases, they also attached those tools to handles to give them better purchase as they sharpened wooden spears or performed other tasks like butchering or scraping leather.
"You need stone tools to cut branches off of trees and make them into a point," Villa said.
The find isn't the oldest known example of hafting by Neanderthals in Europe -- two flakes discovered in the Campitello Quarry in central Italy predate it. But it does suggest that this technique was more common than previously believed.
The existence of hafting also provides more evidence that Neanderthals, like their smaller human relatives, were able to build a fire whenever they wanted one, Villa said -- something that scientists have long debated. She said that pine resin dries when exposed to air. As a result, Neanderthals needed to warm it over a small fired to make an effective glue.
"This is one of several proofs that strongly indicate that Neanderthals were capable of making fire whenever they needed it," Villa said.
In other words, enjoying the glow of a warm campfire isn't just for Homo sapiens.
Read more at Science Daily
Jun 28, 2019
A new normal: Study explains universal pattern in fossil record
Throughout life's history on earth, biological diversity has gone through ebbs and flows -- periods of rapid evolution and of dramatic extinctions. We know this, at least in part, through the fossil record of marine invertebrates left behind since the Cambrian period. Remarkably, extreme events of diversification and extinction happen more frequently than a typical, Gaussian, distribution would predict. Instead of the typical bell-shaped curve, the fossil record shows a fat-tailed distribution, with extreme, outlier, events occurring with higher-than-expected probability.
While scientists have long known about this unusual pattern in the fossil record, they have struggled to explain it. Many random processes that occur over a long time with large sample sizes, from processes that produce school grades to height among a population, converge on the common Gaussian distribution. "It's a very reasonable default expectation," says Santa Fe Institute Omidyar Fellow Andy Rominger. So why doesn't the fossil record display this common pattern?
In a new paper published in Science Advances, Rominger and colleagues Miguel Fuentes (San Sebastián University, Chile) and Pablo Marquet (Pontifical Catholic University of Chile) have taken a new approach to tackling this question. Instead of trying to only describe fluctuations in biodiversity across all types of organisms, they also look at fluctuations within clades, or groups of organisms that share a common ancestral lineage.
"Within a lineage of closely related organisms, there should be a conserved evolutionary dynamic. Between different lineages, that dynamic can change," says Rominger. That is, within clades, related organisms tend to find an effective adaptive strategy and never stray too far. But between these clade-specific fitness peaks are valleys of metaphorically uninhabited space. "It turns out, just invoking that simple idea, with some very simple mathematics, described the patterns in the fossil record very well."
These simple mathematics are tools that Fuentes, in 2009, used to describe another system with an unusual fat-tailed distribution: the stock market. By using superstatistics -- an approach from thermodynamics to describe turbulent flow -- Fuentes could accurately describe the hard-to-predict dramatic crashes and explosions in value.
"In biology, we see these crashes and explosions too, in terms of biodiversity," says Rominger. "We wondered if Fuentes' elegant approach could also describe the evolutionary dynamics we see in the fossil record."
Read more at Science Daily
While scientists have long known about this unusual pattern in the fossil record, they have struggled to explain it. Many random processes that occur over a long time with large sample sizes, from processes that produce school grades to height among a population, converge on the common Gaussian distribution. "It's a very reasonable default expectation," says Santa Fe Institute Omidyar Fellow Andy Rominger. So why doesn't the fossil record display this common pattern?
In a new paper published in Science Advances, Rominger and colleagues Miguel Fuentes (San Sebastián University, Chile) and Pablo Marquet (Pontifical Catholic University of Chile) have taken a new approach to tackling this question. Instead of trying to only describe fluctuations in biodiversity across all types of organisms, they also look at fluctuations within clades, or groups of organisms that share a common ancestral lineage.
"Within a lineage of closely related organisms, there should be a conserved evolutionary dynamic. Between different lineages, that dynamic can change," says Rominger. That is, within clades, related organisms tend to find an effective adaptive strategy and never stray too far. But between these clade-specific fitness peaks are valleys of metaphorically uninhabited space. "It turns out, just invoking that simple idea, with some very simple mathematics, described the patterns in the fossil record very well."
These simple mathematics are tools that Fuentes, in 2009, used to describe another system with an unusual fat-tailed distribution: the stock market. By using superstatistics -- an approach from thermodynamics to describe turbulent flow -- Fuentes could accurately describe the hard-to-predict dramatic crashes and explosions in value.
"In biology, we see these crashes and explosions too, in terms of biodiversity," says Rominger. "We wondered if Fuentes' elegant approach could also describe the evolutionary dynamics we see in the fossil record."
Read more at Science Daily
People's motivations bias how they gather information
A new study suggests people stop gathering evidence earlier when the data supports their desired conclusion than when it supports the conclusion they wish was false. Filip Gesiarz, Donal Cahill and Tali Sharot of University College London, U.K. report in PLOS Computational Biology.
Previous studies had already provided some clues that people gather less information before reaching desirable beliefs. For example, people are more likely to seek a second medical opinion when the first diagnosis is grave. However, certain design limitations of those studies prevented a definitive conclusion and the reasons behind this bias was previously unknown. By fitting people's behavior to a mathematical model Gesiarz and colleagues were able to identify the reasons for this bias.
"Our research suggests that people start with an assumption that their favored conclusion is more likely true and weight each piece of evidence supporting it more than evidence opposing it. Because of that, people will find no need to gather additional information that could have revealed their conclusion to be false. They will stop the investigation as soon as the jury tilts in their favor" said Gesiarz.
In this new study 84 volunteers played an online categorization game in which they could gather as much evidence as they wanted to help them make judgements and were paid according to how accurate they were. In addition, if the evidence pointed to a certain category they would get bonus points and if it pointed to another category they would lose points. So while there was reason to wish the evidence pointed to a specific judgement, the only way for volunteers to maximize rewards was to provide accurate responses. Despite this, they found that the volunteers stopped gathering data earlier when it supported the conclusion they wished was true than when it supported the undesirable conclusion.
"Today, a limitless amount of information is available at the click of a mouse," Sharot says. "However, because people are likely to conduct less through searches when the first few hits provide desirable information, this wealth of data will not necessarily translate to more accurate beliefs."
Next, the authors hope to determine what factors make certain individuals more likely to have a bias in how they gather information than others. For instance, they are curious whether children might show the same bias revealed in this study, or whether people with depression, which is associated with motivation problems, have different data-gathering patterns.
From Science Daily
Previous studies had already provided some clues that people gather less information before reaching desirable beliefs. For example, people are more likely to seek a second medical opinion when the first diagnosis is grave. However, certain design limitations of those studies prevented a definitive conclusion and the reasons behind this bias was previously unknown. By fitting people's behavior to a mathematical model Gesiarz and colleagues were able to identify the reasons for this bias.
"Our research suggests that people start with an assumption that their favored conclusion is more likely true and weight each piece of evidence supporting it more than evidence opposing it. Because of that, people will find no need to gather additional information that could have revealed their conclusion to be false. They will stop the investigation as soon as the jury tilts in their favor" said Gesiarz.
In this new study 84 volunteers played an online categorization game in which they could gather as much evidence as they wanted to help them make judgements and were paid according to how accurate they were. In addition, if the evidence pointed to a certain category they would get bonus points and if it pointed to another category they would lose points. So while there was reason to wish the evidence pointed to a specific judgement, the only way for volunteers to maximize rewards was to provide accurate responses. Despite this, they found that the volunteers stopped gathering data earlier when it supported the conclusion they wished was true than when it supported the undesirable conclusion.
"Today, a limitless amount of information is available at the click of a mouse," Sharot says. "However, because people are likely to conduct less through searches when the first few hits provide desirable information, this wealth of data will not necessarily translate to more accurate beliefs."
Next, the authors hope to determine what factors make certain individuals more likely to have a bias in how they gather information than others. For instance, they are curious whether children might show the same bias revealed in this study, or whether people with depression, which is associated with motivation problems, have different data-gathering patterns.
From Science Daily
Some corals can survive in acidified ocean conditions, but have lower density skeletons
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| Coral reef. |
The study took advantage of the unusual seawater chemistry found naturally at sites along the Caribbean coastline of Mexico's Yucatan Peninsula, where water discharging from submarine springs has lower pH than the surrounding seawater, with reduced availability of the carbonate ions corals need to build their calcium carbonate skeletons.
In a two-year field experiment, the international team of researchers transplanted genetically identical fragments of three species of corals to a site affected by the springs and to a nearby control site not influenced by the springs, and then monitored the survival, growth rates, and other physiological traits of the transplants. They reported their findings in a paper published June 26 in Proceedings of the Royal Society B.
"The good news is the corals can survive and deposit calcium carbonate, but the density of their skeletons is reduced, which means the framework of the reef would be less robust and might be more susceptible to storm damage and bioerosion," said Adina Paytan, a research professor at UCSC's Institute of Marine Sciences and corresponding author of the paper.
Of the three species tested, the one that performed best in the low-pH conditions was Siderastrea siderea, commonly known as massive starlet coral, a slow-growing species that forms large dome-shaped structures. Another slow-growing dome-shaped species, Porites astreoides (mustard hill coral), did almost as well, although its survival rate was 20 percent lower. Both of these species outperformed the fast-growing branching coral Porites porites (finger coral).
Coauthor Donald Potts, professor of ecology and evolutionary biology at UC Santa Cruz, said the transplanted species are all widespread throughout the Caribbean. "The slow-growing, dome-shaped corals tend to be more tolerant of extreme conditions, and they are important in building up the permanent structure of the reef," he said. "We found that they have the potential for persistence in acidified conditions."
Corals will have to cope with more than ocean acidification, however. The increasing carbon dioxide level in the atmosphere is also driving climate change, resulting in warmer ocean temperatures and rising sea levels. Unusually warm temperatures can disrupt the symbiosis between coral polyps and the algae that live in them, leading to coral bleaching. And rapidly rising sea levels could leave slow-growing corals at depths where they would die from insufficient sunlight.
Nevertheless, Potts noted that several species of Caribbean corals have long fossil records showing that they have persisted through major changes in Earth's history. "These are species with a history of survival and tolerance," he said.
He added that both S. siderea and P. astreoides had higher chlorophyll concentrations at the low-pH site, indicating that their algal symbionts were responding positively and potentially increasing the energy resources available to the corals for resisting stress.
Both of the slow-growing species that did well under acidified conditions have internal fertilization and brood their larvae, so that their offspring have the potential to settle immediately in the same area, Potts said. "This means there is potential for local genetic adaptation over successive generations to changing environmental conditions," he said.
The authors also noted that the differences among coral species in survival and calcification under acidified conditions could be useful information for reef restoration efforts and perhaps even for efforts to genetically modify corals to give them greater stress tolerance.
Paytan said she remains "cautiously optimistic," despite the many threats facing coral reefs worldwide.
"These corals are more robust than we thought," she said. "They have the potential to persist with ocean acidification, but it costs them energy to cope with it, so we have to do all we can to reduce other stressors, such as nutrient pollution and sedimentation."
Read more at Science Daily
Jun 27, 2019
Some extinct crocs were vegetarians
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| American alligator. |
"The most interesting thing we discovered was how frequently it seems extinct crocodyliforms ate plants," said Keegan Melstrom, a doctoral student at the University of Utah. "Our study indicates that complexly-shaped teeth, which we infer to indicate herbivory, appear in the extinct relatives of crocodiles at least three times and maybe as many as six."
All living crocodylians possess a similar general body shape and ecology to match their lifestyle as semiaquatic generalist carnivores, which includes relatively simple, conical teeth. It was clear from the start of the study that extinct species showed a different pattern, including species with many specializations not seen today. One such specialization is a feature known as heterodonty: regionalized differences in tooth size or shape.
"Carnivores possess simple teeth whereas herbivores have much more complex teeth," Melstrom explained. "Omnivores, organisms that eat both plant and animal material, fall somewhere in between. Part of my earlier research showed that this pattern holds in living reptiles that have teeth, such as crocodylians and lizards. So these results told us that the basic pattern between diet and teeth is found in both mammals and reptiles, despite very different tooth shapes, and is applicable to extinct reptiles."
To infer what those extinct crocodyliforms most likely ate, Melstrom and his graduate advisor, chief curator Randall Irmis, compared the tooth complexity of extinct crocodyliforms to those of living animals using a method originally developed for use in living mammals. Overall, they measured 146 teeth from 16 different species of extinct crocodyliforms.
Using a combination of quantitative dental measurements and other morphological features, the researchers reconstructed the diets of those extinct crocodyliforms. The results show that those animals had a wider range of dental complexities and presumed dietary ecologies than had been appreciated previously.
Plant-eating crocodyliforms appeared early in the evolutionary history of the group, the researchers conclude, shortly after the end-Triassic mass extinction, and persisted until the end-Cretaceous mass extinction that killed off all dinosaurs except birds. Their analysis suggests that herbivory arose independently a minimum of three times, and possibly six times, in Mesozoic crocodyliforms.
"Our work demonstrates that extinct crocodyliforms had an incredibly varied diet," Melstrom said. "Some were similar to living crocodylians and were primarily carnivorous, others were omnivores and still others likely specialized in plants. The herbivores lived on different continents at different times, some alongside mammals and mammal relatives, and others did not. This suggests that an herbivorous crocodyliform was successful in a variety of environments!"
Melstrom says they are continuing to reconstruct the diets of extinct crocodyliforms, including in fossilized species that are missing teeth. He also wants to understand why the extinct relatives of crocodiles diversified so radically after one mass extinction but not another, and whether dietary ecology could have played a role.
Read more at Science Daily
Honeybees infect wild bumblebees through shared flowers
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| Honeybee on flower. |
Several of the viruses associated with bumblebees' trouble are moving from managed bees in apiaries to nearby populations of wild bumblebees -- "and we show this spillover is likely occurring through flowers that both kinds of bees share," says Samantha Alger, a scientist at the University of Vermont who led the new research.
"Many wild pollinators are in trouble and this finding could help us protect bumblebees," she says. "This has implications for how we manage domestic bees and where we locate them."
The first-of-its-kind study was published June 26 in the journal PLOS ONE.
Virus Hunters
Around the globe, the importance of wild pollinators has been gaining attention as diseases and declines in managed honeybees threaten key crops. Less well understood is that many of the threats to honeybees (Apis mellifera) -- including land degradation, certain pesticides, and diseases -- also threaten native bees, such as the rusty patched bumblebee, recently listed under the Endangered Species Act; it has declined by nearly 90% but was once an excellent pollinator of cranberries, plums, apples and other agricultural plants.
The research team -- three scientists from the University of Vermont and one from the University of Florida -- explored 19 sites across Vermont. They discovered that two well-know RNA viruses found in honeybees -- deformed wing virus and black queen cell virus -- were higher in bumblebees collected less than 300 meters from commercial beehives. The scientists also discovered that active infections of the deformed wing virus were higher near these commercial apiaries but no deformed wing virus was found in the bumblebees they collected where foraging honeybees and apiaries were absent.
Most impressive, the team detected viruses on 19% of the flowers they sampled from sites near apiaries. "I thought this was going to be like looking for a needle in a haystack. What are the chances that you're going to pick a flower and find a bee virus on it?" says Alger. "Finding this many was surprising." In contrast, the scientists didn't detect any bee viruses on flowers sampled more than one kilometer from commercial beehives.
The UVM scientists -- including Alger and co-author Alex Burnham, a doctoral student -- and other bee experts have for some years suspected that RNA viruses might move from honeybees to bumblebees through shared flowers. But -- with the exception of one small study in a single apiary -- the degree to which these viruses can be "horizontally transmitted," the scientists write, with flowers as the bridge, has not been examined until now.
Taken together, these results strongly suggest that "viruses in managed honeybees are spilling over to wild bumblebee populations and that flowers are an important route," says Alison Brody, a professor in UVM's Department of Biology, and senior author on the new PLOS study. "Careful monitoring and treating of diseased honeybee colonies could protect wild bees from these viruses as well as other pathogens or parasites."
Just Like Chicken?
Alger -- an expert beekeeper and researcher in UVM's Department of Plant & Soil Science and Gund Institute for Environment -- is deeply concerned about the long-distance transport of large numbers of honeybees for commercial pollination. "Big operators put hives on flatbed trucks and move them to California to pollinate almonds and then onto Texas for another crop," she says -- carrying their diseases wherever they go. And between bouts of work on monoculture farm fields, commercial bees are often taken to more pristine natural habitats "to rest and recover, where there is diverse, better forage," says Alger.
"This research suggests that we might want to keep apiaries outside of areas where there are vulnerable pollinator species, like the rusty patched bumblebees," Alger says, "especially because we have so much more to learn about what these viruses are actually doing to bumblebees."
Read more at Science Daily
Thunderbolts of lightning, gamma rays exciting
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| Lightning storm |
In the city of Kanazawa, Ishikawa Prefecture, in central Japan, Wada and colleagues work with local schools and businesses to install radiation monitors onto buildings. These radiation monitors are not there due to some worry about local radiation levels, though. They form a network, the purpose of which is to detect radiation coming from the sky. It may surprise some, but it's been known for around 30 years that thunderstorms can bring with them gamma-ray activity.
"Forever, people have seen lightning and heard thunder. These were the ways we could experience this power of nature," said Wada. "With the discovery of electromagnetism, scientists learned to see lightning with radio receivers. But now we can observe lightning in gamma rays -- ionizing radiation. It's like having four eyes to study the phenomena."
There are two known kinds of gamma-ray phenomena associated with thunderclouds: gamma-ray glows, weak emissions which last about a minute, and short-lived terrestrial gamma-ray flashes (TGFs), which occur as lightning strikes and are much more intense than gamma-ray glows. Both occur in regions of thunderclouds sandwiched between layers of varying charge. The charged regions accelerate electrons to near the speed of light. At these speeds, referred to as relativistic, electrons that stray very close to the nuclei of nitrogen atoms in the air slow down a little and emit a telltale gamma ray. This is called bremsstrahlung radiation.
"During a winter thunderstorm in Kanazawa, our monitors detected a simultaneous TGF and lightning strike. This is fairly common, but interestingly we also saw a gamma-ray glow in the same area at the same time," continued Wada. "Furthermore, the glow abruptly disappeared when the lightning struck. We can say conclusively the events are intimately connected and this is the first time this connection has been observed."
The mechanism underlying lightning discharge is highly sought after and this research may offer previously unknown insights. Wada and team intend to further their investigation to explore the possibility that gamma-ray glows don't just precede lightning strikes, but may in fact cause them. Radiation levels of the gamma-ray flashes are quite low, approximately a tenth the level one may receive from a typical medical X-ray.
"Our finding marks a milestone in lightning research and we will soon double our number of radiation sensors from 23 to about 40 or 50. With more sensors, we could greatly improve predictive models," explained Wada. "It's hard to say right now, but with sufficient sensor data, we may be able to predict lightning strikes within about 10 minutes of them happening and within around 2 kilometers of where they happen. I'm excited to be part of this ongoing research."
Further investigations will likely still take place in Kanazawa as the area has rare and ideal meteorological conditions for this kind of work. Most radiation observations in storms come from airborne or mountain-based stations as thunderclouds are generally very high up. But winter storms in Kanazawa bring thunderclouds surprisingly close to the ground, ideal for study with the low-cost portable monitors developed by the research team.
The researchers created these unique portable radiation monitors in part with technology derived from space-based satellite observatories designed for astrophysics experiments. This is appropriate as the data from this kind of research could be useful for those who research astrophysics and in particular solar physics in the context of particle acceleration. But there is a more down-to-earth offshoot as well.
"Paleontologists who study life from the last 50,000 years or so use a technique called carbon-14 dating to determine the age of a sample. The technique relies on knowledge of the levels of two kinds of carbon, carbon-12 and carbon-14," said Wada. "It's commonly thought carbon-14 is created by cosmic rays at a roughly constant rate, hence the predictive power of the technique. But there's a suggestion thunderstorms may alter the ratio of carbon-12 to carbon-14, which may slightly change the accuracy of or calibration required for carbon-14 dating to work."
Read more at Science Daily
ALMA pinpoints the formation site of planet around nearest young star
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| Planetary disk around star. |
The young star TW Hydrae, located194 light-years away in the constellation Hydra, is the closest star around which planets may be forming. Its surrounding dust disk is the best target to study the process of planet formation.
Previous ALMA observations revealed that the disk is composed of concentric rings. Now, new higher sensitivity ALMA observations revealed a previously unknown small clump in the planet forming disk. The clump is elongated along the direction of the disk rotation, with a width approximately equal to the distance between the Sun and the Earth, and a length of about four-and-a-half times that.
"The true nature of the clump is still not clear," says Takashi Tsukagoshi at the National Astronomical Observatory of Japan and the lead author of the research paper. "It could be a 'circumplanetary' disk feeding a Neptune-sized infant planet. Or it might be that swirling gas is raking up the dust particles."
Planets form in disks of gas and dust around young stars. Micrometer-sized dust particles stick together to grow to larger grains, rocks, and finally a planet. Theoretical studies predict that an infant planet is surrounded by a 'circumplanetary' disk, a small structure within the larger dust disk around the star. The planet collects material through this circumplanetary disk. It is important to find such a circumplanetary disk to understand the final stage of planet growth.
Cold dust and gas in the disks around young stars are difficult to see in visible light, but they emit radio waves. With its high sensitivity and resolution for such radio waves, ALMA is one of the most powerful instruments to study the genesis of planets.
However, the brightness and elongated shape of the structure revealed by ALMA don't exactly match theoretical predictions for circumplanetary disks. It might be a gas vortex, which are also expected to form here and there around a young star. Finding only a single dust clump at this time is also contrary to theoretical studies. So the research team could not reach a definitive answer on the nature of the dusty clump.
Read more at Science Daily
Jun 26, 2019
Cyanide compounds discovered in meteorites may hold clues to the origin of life
Cyanide and carbon monoxide are both deadly poisons to humans, but compounds containing iron, cyanide, and carbon monoxide discovered in carbon-rich meteorites by a team of scientists at Boise State University and NASA may have helped power life on early Earth. The extraterrestrial compounds found in meteorites resemble the active site of hydrogenases, which are enzymes that provide energy to bacteria and archaea by breaking down hydrogen gas (H2). Their results suggest that these compounds were also present on early Earth, before life began, during a period of time when Earth was constantly bombarded by meteorites and the atmosphere was likely more hydrogen-rich.
"When most people think of cyanide, they think of spy movies -- a guy swallowing a pill, foaming at the mouth and dying, but cyanide was probably an essential compound for building molecules necessary for life," explained Dr. Karen Smith, senior research scientist at Boise State University, Boise, Idaho. Cyanide, a carbon atom bound to a nitrogen atom, is thought to be crucial for the origin of life, as it is involved in the non-biological synthesis of organic compounds like amino acids and nucleobases, which are the building blocks of proteins and nucleic acids used by all known forms of life.
Smith is lead author of a paper on this research published June 25 in Nature Communications. Smith, along with Boise State assistant professor Mike Callahan, a co-author on the paper, developed new analytical methods to extract and measure ancient traces of cyanide in meteorites. They found that the meteorites containing cyanide belong to a group of carbon-rich meteorites called CM chondrites. Other types of meteorites tested, including a Martian meteorite, contained no cyanide.
"Data collected by NASA's OSIRIS-REx spacecraft of asteroid Bennu indicate that it is related to CM chondrites," said co-author Jason Dworkin of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "OSIRIS-REx will deliver a sample from Bennu to study on Earth in 2023. We will search for these very compounds to try to connect Bennu to known meteorites and to understand the potential delivery of prebiotic compounds such as cyanide, which may have helped start life on the early Earth or other bodies in the solar system."
Cyanide has been found in meteorites before. However, in the new work, Smith and Callahan were surprised to discover that cyanide, along with carbon monoxide (CO), were binding with iron to form stable compounds in the meteorites. They identified two different iron cyano-carbonyl complexes in the meteorites using high-resolution liquid chromatography-mass spectrometry. "One of the most interesting observations from our study is that these iron cyano-carbonyl complexes resemble portions of the active sites of hydrogenases, which have a very distinct structure," Callahan said.
Hydrogenases are present in almost all modern bacteria and archaea and are widely believed to be ancient in origin. Hydrogenases are large proteins, but the active site -- the region where chemical reactions take place -- happens to be a much smaller metal-organic compound contained within the protein, according to Callahan. It is this compound that resembles the cyanide-bearing compounds the team discovered in meteorites.
An enduring mystery regarding the origin of life is how biology could have arisen from non-biological chemical processes. The similarities between the active sites in hydrogenase enzymes and the cyanide compounds the team found in meteorites suggests that non-biological processes in the parent asteroids of meteorites and on ancient Earth could have made molecules useful to emerging life.
Read more at Science Daily
"When most people think of cyanide, they think of spy movies -- a guy swallowing a pill, foaming at the mouth and dying, but cyanide was probably an essential compound for building molecules necessary for life," explained Dr. Karen Smith, senior research scientist at Boise State University, Boise, Idaho. Cyanide, a carbon atom bound to a nitrogen atom, is thought to be crucial for the origin of life, as it is involved in the non-biological synthesis of organic compounds like amino acids and nucleobases, which are the building blocks of proteins and nucleic acids used by all known forms of life.
Smith is lead author of a paper on this research published June 25 in Nature Communications. Smith, along with Boise State assistant professor Mike Callahan, a co-author on the paper, developed new analytical methods to extract and measure ancient traces of cyanide in meteorites. They found that the meteorites containing cyanide belong to a group of carbon-rich meteorites called CM chondrites. Other types of meteorites tested, including a Martian meteorite, contained no cyanide.
"Data collected by NASA's OSIRIS-REx spacecraft of asteroid Bennu indicate that it is related to CM chondrites," said co-author Jason Dworkin of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "OSIRIS-REx will deliver a sample from Bennu to study on Earth in 2023. We will search for these very compounds to try to connect Bennu to known meteorites and to understand the potential delivery of prebiotic compounds such as cyanide, which may have helped start life on the early Earth or other bodies in the solar system."
Cyanide has been found in meteorites before. However, in the new work, Smith and Callahan were surprised to discover that cyanide, along with carbon monoxide (CO), were binding with iron to form stable compounds in the meteorites. They identified two different iron cyano-carbonyl complexes in the meteorites using high-resolution liquid chromatography-mass spectrometry. "One of the most interesting observations from our study is that these iron cyano-carbonyl complexes resemble portions of the active sites of hydrogenases, which have a very distinct structure," Callahan said.
Hydrogenases are present in almost all modern bacteria and archaea and are widely believed to be ancient in origin. Hydrogenases are large proteins, but the active site -- the region where chemical reactions take place -- happens to be a much smaller metal-organic compound contained within the protein, according to Callahan. It is this compound that resembles the cyanide-bearing compounds the team discovered in meteorites.
An enduring mystery regarding the origin of life is how biology could have arisen from non-biological chemical processes. The similarities between the active sites in hydrogenase enzymes and the cyanide compounds the team found in meteorites suggests that non-biological processes in the parent asteroids of meteorites and on ancient Earth could have made molecules useful to emerging life.
Read more at Science Daily
Algorithm designed to map universe, solve mysteries
Cornell University researchers have developed an algorithm designed to visualize models of the universe in order to solve some of physics' greatest mysteries.
The algorithm was developed by applying scientific principles used to create models for understanding cell biology and physics to the challenges of cosmology and big data.
"Science works because things behave much more simply than they have any right to," said professor of physics James Sethna. "Very complicated things end up doing rather simple collective behavior."
Sethna is the senior author of "Visualizing Probabilistic Models With Intensive Principal Component Analysis," published in the Proceedings of the National Academy of Sciences.
The algorithm, designed by first author Katherine Quinn, allows researchers to image a large set of probabilities to look for patterns or other information that might be useful, and provides them with better intuition for understanding complex models and data.
"A person can't just sit down and do it," Quinn said. "We need better algorithms that can extract what we're interested in, without being told what to look for. We can't just say, 'Look for interesting universes.' This algorithm is a way of untangling information in a way that can reveal the interesting structure of the data."
Further complicating the researchers' task was the fact that the data consists of ranges of probabilities, rather than raw images or numbers.
Their solution takes advantage of different properties of probability distributions to visualize a collection of things that could happen. In addition to cosmology, their model has applications to machine learning and statistical physics, which also work in terms of predictions.
To test the algorithm, the researchers used data from the European Space Agency's Planck satellite, and studied it with co-author Michael Niemack, associate professor of physics. They applied the model data on the cosmic microwave background -- radiation left over from the universe's early days.
The model produced a map depicting possible characteristics of different universes, of which our own universe is one point.
This new method of visualizing the qualities of our universe highlights the hierarchical structure of the dark energy and dark matter dominated model that fits the cosmic microwave background data so well. These visualizations present a promising approach for optimizing cosmological measurements in the future, Niemack said.
Read more at Science Daily
The algorithm was developed by applying scientific principles used to create models for understanding cell biology and physics to the challenges of cosmology and big data.
"Science works because things behave much more simply than they have any right to," said professor of physics James Sethna. "Very complicated things end up doing rather simple collective behavior."
Sethna is the senior author of "Visualizing Probabilistic Models With Intensive Principal Component Analysis," published in the Proceedings of the National Academy of Sciences.
The algorithm, designed by first author Katherine Quinn, allows researchers to image a large set of probabilities to look for patterns or other information that might be useful, and provides them with better intuition for understanding complex models and data.
"A person can't just sit down and do it," Quinn said. "We need better algorithms that can extract what we're interested in, without being told what to look for. We can't just say, 'Look for interesting universes.' This algorithm is a way of untangling information in a way that can reveal the interesting structure of the data."
Further complicating the researchers' task was the fact that the data consists of ranges of probabilities, rather than raw images or numbers.
Their solution takes advantage of different properties of probability distributions to visualize a collection of things that could happen. In addition to cosmology, their model has applications to machine learning and statistical physics, which also work in terms of predictions.
To test the algorithm, the researchers used data from the European Space Agency's Planck satellite, and studied it with co-author Michael Niemack, associate professor of physics. They applied the model data on the cosmic microwave background -- radiation left over from the universe's early days.
The model produced a map depicting possible characteristics of different universes, of which our own universe is one point.
This new method of visualizing the qualities of our universe highlights the hierarchical structure of the dark energy and dark matter dominated model that fits the cosmic microwave background data so well. These visualizations present a promising approach for optimizing cosmological measurements in the future, Niemack said.
Read more at Science Daily
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