Science

Drastically falling insect numbers could cause ‘ecological Armageddon’ — study

Researchers in Germany have documented a dramatic decline in flying insects at dozens of nature reserves in the past three decades that they say could lead to an “ecological Armageddon,” and agricultural pesticides may be to blame, according to a new study published Wednesday.

While it is well documented that butterflies and bees have been disappearing in Europe and North America, the study published in PLOS ONE is the first to document that flying insects in general have decreased by more than three-quarters across Germany since 1989.

Researchers are concerned because insects are important pollinators and also a key part of the food chain, serving as meals for birds and other small creatures.

“The fact that flying insects are decreasing at such a high rate in such a large area is an even more alarming discovery,” said lead researcher Hans de Kroon of Radboud University.

“Insects make up about two-thirds of all life on Earth but there has been some kind of horrific decline,” said Prof Dave Goulson of Sussex University in the UK. “We appear to be making vast tracts of land inhospitable to most forms of life, and are currently on course for ecological Armageddon. If we lose the insects then everything is going to collapse.”

For the study, researchers used sticky traps to collect insects at 63 nature reserves, then measured the biomass, documenting changes over time. Over the past 27 years, they found an average decline of 76 percent, with the effects appearing worst in summer (82%).

“All these areas are protected and most of them are managed nature reserves. Yet, this dramatic decline has occurred,” said co-author Caspar Hallmann from Radboud University.

While the study did not pinpoint a reason for the drop, researchers said many nature reserves are encircled by farm fields, and that pesticides could be to blame.

“As entire ecosystems are dependent on insects for food and as pollinators, it places the decline of insect eating birds and mammals in a new context,” said de Kroon.

“We need to do less of the things that we know have a negative impact, such as the use of pesticides,” he added. “We also have to work hard at extending our nature reserves and decreasing the ratio of reserves that border agricultural areas.”

Advertisements

ALLIGATORS ARE FEASTING ON SHARKS IN AMERICA’S RIVERS AND ESTUARIES, SCIENTISTS DISCOVER

There is always a bigger fish, the old adage goes and if there isn’t, at the very least there is a bigger alligator, new research confirms.

Even when it comes to sharks—an infamous predator of the sea—as they risk becoming prey to the American alligator when they venture into freshwater, a study published in Southeastern Naturalist confirms.

The study of the stomach contents of 500 living alligators captured and examined by Kansas State University researcher James Nifong and IMSS wildlife biologist Russell Lowers unveiled four different species of sharks, including nurse sharks and stingrays.

The American alligator, also known as Alligator mississippiensis, and the various types of sharks usually swim in waters that rarely overlap as alligators are freshwater dwellers, while sharks top food chains in salt waters.

On the rare occasion where either species feels some wanderlust for the other’s ecosystem, the alligator is liable to swap its meal of crustaceans, snails, and smaller fish for more vicious prey.

gator-shark-smAmerican alligator preying on a nurse shark.U.S. FISH AND WILDLIFE SERVICE J.N. “DING” DARLING NATIONAL WILDLIFE REFUGE.

Sharks have been spotted slipping into freshwater areas on occasion. Equally, while alligators lack salt glands—a requirement if their body is to filter the saltwater they plan on surviving in—the species can suss out whenever saltwater becomes temporarily diluted, after heavy rainfall for example.

“Alligators seek out fresh water in high-salinity environments,” said Nifong in a statement. “When it rains really hard, they can actually sip fresh water off the surface of the saltwater. That can prolong the time they can stay in a saltwater environment.”

Alligators are not inherently the victor in an altercation with any shark, however. In fact, as the relationship between the two species becomes closer, what the dynamic between them looks like is more of mutual hunting or “reciprocal predation.” In other words, it is likely that once hungry and pitted in the same environment, it is a question of size that determines if the alligator eats the shark or vice versa.

“The frequency of one predator eating the other is really about size dynamic,” Nifong said “If a small shark swims by an alligator and the alligator feels like it can take the shark down, it will, but we also reviewed some old stories about larger sharks eating smaller alligators.”

Big and Brilliant: Complex Whale Behavior Tied to Brain Size

WASHINGTON (Reuters) – Cetaceans — whales and dolphins — are among the brainiest of beings. In terms of sheer brain size, the sperm whale is tops on Earth, with a brain six times larger than that of a person.

And now, scientists have identified key differences among cetaceans linked to brain size. A study of 90 cetacean species published on Monday found that those with larger brains exhibit greater complexity in social structures and behaviors, with species like the killer whale and sperm whale leading the way.

“Dolphin and whale societies are at least as complex as what we have observed in primates,” said evolutionary biologist Susanne Shultz of the University of Manchester in Britain.

“They are extremely playful, they learn from each other,have complex communication. One problem for understanding justhow smart they are is how difficult it is to observe them and to understand their marine world. Therefore, we have only a glimpse of what they are capable of.”The researchers created a comprehensive database of brain size, social structures and cultural behaviors across cetacean species. The group of species with the largest brain size relative to body size was the large whale-like dolphins such as the killer whale, the similar-looking false killer whale and the pilot whale, Shultz said.

“Killer whales have cultural food preferences, have matriarchs that lead and teach other group members, and cooperatively hunt,” Shultz said.

In terms of intra-species food preferences, certain killerwhale populations, also known as orcas, prefer salmon whereas others prefer seals or other whales or sharks depending on their group’s culture.Other big-brained cetaceans also demonstrate sophisticated behaviors.

Mother sperm whales organize babysitting duties using other members of their pod to protect their young while they hunt for food down deep. The distinctive vocalizations sperm whales use to communicate sometimes differ depending upon where they live, much like regional dialects in human language.

Bottlenose dolphins use sea sponges as tools to protect their beaks while foraging for food, and live in structured communities.

Some of the largest cetaceans — filter-feeding baleen whales like the blue whale, fin whale and humpback whale that eat tiny crustaceans called krill rather than fish or squid — were on the low end of relative brain size. They live fairly solitary lives, coming together only for breeding seasons and near rich food sources.

The research was published in the journal Nature Ecology & Evolution.

What Filthy Old Birds Can Tell Us About Air Pollution

By analyzing sooty birds housed in museum collections, scientists have been able to track patterns of US air pollution over the last 135 years. As the new study shows, air at the turn of the 20th century was even dirtier than we thought—a finding that will now be used to improve our climate models.

Horned larks, in addition to their dazzling yellow chins, feature a white underside that, unfortunately for them, is really good at absorbing tiny bits of black carbon; free-floating atmospheric soot clings to their feathers like dust to a feather duster. Today, most of these songbirds are able to maintain their bright, white appearance, but at the turn of the 20th century, horned larks were a miserable dark grey, particularly in areas where coal was king.

New research published in Proceedings of the National Academy of Sciencesshows that, by tracking the degree of sootiness in these birds over time, scientists can build a historical record of atmospheric soot. In this case, scientists from the Field Museum in Chicago and the University of Chicago compared the amount of soot on 1,347 birds kept in Rust Belt museum collections to track environmental pollution over the past 135 years (Rust Belt cities tracked in the study included Detroit, Chicago, Pittsburgh, etc.).

“The soot on these birds’ feathers allowed us to trace the amount of black carbon in the air over time, and we found that the air at the turn of the century was even more polluted than scientists previously thought,” said Shane DuBay, a co-author of the new study, in a statement. “If you look at Chicago today, the skies are blue. But when you look at pictures of Beijing and Dehli, you get a sense for what US cities like Chicago and Pittsburgh were once like. Using museum collections, we were able to reconstruct that history.”

Image: Carl Fuldner and Shane DuBay, The University of Chicago and The Field Museum

Atmospheric black carbon is still a serious public health and environmental concern. Produced by burning coal, it’s a major contributor to human-instigated climate change. Scientists need accurate environmental data to track historical changes in air pollution over time, and crucially, to build increasingly accurate models for future climate scenarios. Unfortunately, however, modern environmental sampling didn’t start until the 1950s, so there’s a big gap in the scientific literature. This latest study is an effort to fill in some of this missing data.

As this new study reveals, that missing data is embedded within the feathers of birds kept in natural history collections. Ornithologists at the Field Museum and elsewhere are well aware that specimens from the early 1900s are darker than expected, with atmospheric soot considered the likely culprit.

For the study, co-author Carl Fuldner developed a photographic technique that allowed him to measure the amount of reflected light bouncing off the birds (fewer reflections means more soot has been absorbed by the feathers). Fuldner and DuBay analyzed five different species of birds with this technique, all of which lived and bred in the Manufacturing Belt of the United States.

The researchers then plotted the amount of reflective light to the year in which the birds were collected (between 1880 and 2015), while also looking into the social history of urban air pollution.

“We were surprised by the precision we were able to achieve,” said DuBay in the statement. “The soot on the birds closely tracks the use of coal over time. During the Great Depression, there’s a sharp drop in black carbon on the birds because coal consumption dropped—once we saw that, it clicked.”

In addition, scientists documented an increase in bird sootiness during the Second World War, when wartime manufacturing drove up coal use, and a quick drop off after the war when people in the Rust Belt began to heat their homes with natural gas instead of coal.

“The fact that the more recent birds are cleaner doesn’t mean we’re in the clear,” DuBay cautions. “While the US releases far less black carbon into the atmosphere than we used to, we continue to pump less-conspicuous pollutants into our atmosphere—those pollutants just aren’t as visible as soot. Plus, many people around the world still experience soot-choked air in their cities.”

This study, in addition to revising our historical climate models, demonstrates the importance of maintaining museum collections. Data can often be found in the places where we least suspect. It also shows that a return to coal is probably not a good idea.

There’s enough wind energy over the oceans to power human civilization, scientists say

New research published on Monday finds there is so much wind energy potential over oceans that it could theoretically be used to generate “civilization scale power” — assuming, that is, that we are willing to cover enormous stretches of the sea with turbines, and can come up with ways to install and maintain them in often extreme ocean environments.

It’s very unlikely that we would ever build out open ocean turbines on anything like that scale — indeed, doing so could even alter the planet’s climate, the research finds. But the more modest message is that wind energy over the open oceans has large potential — reinforcing the idea that floating wind farms, over very deep waters, could be the next major step for wind energy technology.

“I would look at this as kind of a greenlight for that industry from a geophysical point of view,” said Ken Caldeira of the Carnegie Institution for Science in Stanford, Calif. The study, in the Proceedings of the National Academy of Sciences, was led by Carnegie researcher Anna Possner, who worked in collaboration with Caldeira.

The study takes, as its outset, prior research that has found that there’s probably an upper  limit to the amount of energy that can be generated by a wind farm that’s located on land. The limit arises both because natural and human structures on land create friction that slows down the wind speed, but also because each individual wind turbine extracts some of the energy of the wind and transforms it into power that we can use — leaving less wind energy for other turbines to collect.

“If each turbine removes something like half the energy flowing through it, by the time you get to the second row, you’ve only got a quarter of the energy, and so on,” explained Caldeira.

The ocean is different. First, wind speeds can be as much as 70 percent higher than on land. But a bigger deal is what you might call wind replenishment. The new research found that over the mid-latitude oceans, storms regularly transfer powerful wind energy down to the surface from higher altitudes, meaning that the upper limit here for how much energy you can capture with turbines is considerably higher.

“Over land, the turbines are just sort of scraping the kinetic energy out of the lowest part of the atmosphere, whereas over the ocean, it’s depleting the kinetic energy out of most of the troposphere, or the lower part of the atmosphere,” said Caldeira.

The study compares a theoretical wind farm of nearly 2 million square kilometers located either over the U.S. (centered on Kansas) or in the open Atlantic. And it finds that covering much of the central U.S. with wind farms would still be insufficient to power the U.S. and China, which would require a generating capacity of some 7 terawatts annually (a terawatt is equivalent to a trillion watts).

But the North Atlantic could theoretically power those two countries and then some. The potential energy that can be extracted over the ocean, given the same area, is “at least three times as high.”

It would take an even larger, 3 million square kilometer wind installation over the ocean to provide humanity’s current power needs, or 18 terawatts, the study found. That’s an area even larger than Greenland.

Hence, the study concludes that “on an annual mean basis, the wind power available in the North Atlantic could be sufficient to power the world.”

But it’s critical to emphasize that these are purely theoretical calculations. They are thwarted by many practical factors, including the fact that the winds aren’t equally strong in all seasons, and that the technologies to capture their energy at such a scale, much less transfer it to shore, do not currently exist.

Oh, and then there’s another large problem: Modeling simulations performed in the study suggest that extracting this much wind energy from nature would have planetary-scale effects, including cooling down parts of the Arctic by as much as 13 degrees Celsius.

“Trying to get civilization scale power out of wind is a bit asking for trouble,” Caldeira said. But he said the climate effect would be smaller if the amount of energy being tapped was reduced down from these extremely high numbers, and if the wind farms were more spaced out across the globe.

“I think it lends itself to the idea that we’re going to want to use a portfolio of technologies, and not rely on this only,” said Caldeira.

Energy gurus have long said that among renewable sources, solar energy has the greatest potential to scale up and generate terawatt-scale power, enough to satisfy large parts of human energy demand. Caldeira doesn’t dispute that. But his study suggests that at least if open ocean wind becomes accessible someday, it may have considerable potential too.

Alexander Slocum, an MIT mechanical engineering professor who has focused on offshore wind and its potential, and who was not involved in the research, said he considered the paper a “very good study” and that it didn’t seem biased.

“The conclusion implied by the paper that open ocean wind energy farms can provide most of our energy needs is also supported history: as a technology gets becomes constrained (e.g., horse drawn carriages) or monopolized (OPEC), a motivation arises to look around for alternatives,” Slocum continued by email. “The automobile did it to horses, the U.S. did it to OPEC with fracking, and now renewables are doing it to the hydrocarbon industry.”

“The authors do acknowledge that considerable technical challenges come into play in actually harvesting energy from these far off-shore sites, but I appreciate their focus on the magnitude of the resource,” added Julie Lundquist, a wind energy researcher at the University of Colorado, Boulder. “I hope this work will stimulate further interest in deep water wind energy.”

Underscoring the theoretical nature of the calculations, Lundquist added by email that “current and foreseeable wind turbine deployments both on- and off-shore are much smaller than would be required to reach the atmospheric energy limitations that this work and others are concerned with.”

The research points to a kind of third act for wind energy. On land, turbines are very well established and more are being installed every year. Offshore, meanwhile, coastal areas are now also seeing more and more turbine installations, but still in relatively shallow waters.

But to get out over the open ocean, where the sea is often well over a mile deep, is expected to require yet another technology — likely a floating turbine that extends above the water and sits atop some kind of very large submerged floating structure, accompanied by cables that anchor the entire turbine to the seafloor.

Experimentation with the technology is already happening: Statoil is moving to build a large floating wind farm off the coast of Scotland, which will be located in waters around 100 meters deep and have 15 megawatts (million watts) of electricity generating capacity. The turbines are 253 meters tall, but 78 meters of that length refers to the floating part below the sea surface.

“The things that we’re describing are likely not going to be economic today, but once you have an industry that’s starting in that direction, should provide incentive for that industry to develop,” said Caldeira.

This Horrible Stick Bug Is No Longer Extinct, Sorry

A tiny island sits almost four hundred miles from the Eastern coast of Australia. Upon that island once lived a large population of giant stick insects—six inch-long “land lobsters” dwelling in trees—the Dryococelus australis. But a hundred years ago, mankind came along, bringing pests, black rats, with them. The bugs went extinct at the hands of the rats.

But climbers at nearby Balls Pyramid, a jagged crag jutting straight out of the water, spotted a fresh D. australis carcass on a climb during the 1960s. Another survey of Balls Pyramid in 2001 found a few specimens alive on a tree, and a 2002 survey found even more. But the bugs on Balls and those on Lord Howe look completely different, leading scientists to wonder: had they truly found the extinct species once again, or had they stumbled upon completely different animal?

Image: Mikheyev et al, Curr Bio (2017)

The differences between the old and new specimens are obvious, though. The older, supposedly extinct bugs were thicker, with thicker rear legs (C) and differently-shaped cerci, the pair of appendages at their rear (B). Researchers had other reasons to believe that they were looking at a new species, too. It wouldn’t be the first time different species evolved to look the same. Or maybe the two bugs could have once been the same species but were separated by distance for so long that evolution caused them to diverge.

Balls Pyramid (Image: Jon Clark /Wikimedia Commons)

These days, figuring out if two animals are the same requires an understanding of their genomes—the specifics of their DNA code. Stick bugs are an especially challenging species to sequence as they have enormous genomes, with several billion base pairs (the DNA letters), according to the new paper published in Current Biology. But after analyzing both specimens from museums and specimens from Balls Island, the researchers had their answer. The DNA differed by less than one percent, “suggesting that the two populations most likely diverged after the origin of this species and not long enough ago for speciation to have taken place.” The Balls Island bugs were Lord Howe Tree Lobsters.

Better understanding the species is important as researchers hope to one day reintroduce it to its once-native habit. A rat killing program is scheduled to begin on Lord Howe Island in 2018 with the reintroduction to follow. If the genetic analysis had turned up a different species, then the researchers would be introducing a new species to the island, not reintroducing an old one. That’s a completely different story which could potentially lead to unforeseen ecological problems if the species is brought to a place it doesn’t belong.

All of this goes to show just how useful museum collections can be to science—knowledge gleaned from an old, dead bug could potentially save its entire species a hundred years later.

‘WHO IS A JEW?’ CAN NOW BE ANSWERED BY GENETIC TESTING

 

A new ruling in Jewish law permitting a specific genetic test to be used as proof of Jewish descent for certain Ashkenazi Jews is being promoted as a possible solution for potentially hundreds of thousands of Israeli citizens from the former Soviet Union (FSU) having difficulty proving their Jewish status.

The ruling comes from Rabbi Yosef Carmel, who is both co-head of the Eretz Hemdah Institute for Advanced Jewish Studies and a senior rabbinical judge on the private Eretz Hemdah rabbinical court in south Jerusalem.

The mass immigration of Jews from the FSU to Israel was widely seen as a welcome blessing for the country, but many of them have experienced difficulties proving their Jewish identity for marriage and other personal status requirements due to the suppression of religious activity by the former Soviet regime.

This has caused, and continues to cause, severe problems for these immigrants and their descendants, and threatens to become a wider social problem if ever-greater numbers of such people have their Jewish status rejected by the rabbinical courts and the Chief Rabbinate, as has been happening of late.

A new volume of responsa on matters of Jewish law, written at the Eretz Hemdah Institute under the direction and guidance of Carmel and Rabbi Moshe Ehrenreich, who also co-heads the institute, deals with a case in Munich, Germany, several years ago in which a woman sought to join a Jewish community and claimed to be Jewish.

She was asked for proof of her Jewish status, but much of her family had perished in the Holocaust and her living relatives would not help her since her maternal grandmother had survived and vowed not to have any further connection to the Jewish people. With no other way of proving her Jewish lineage, the woman took a mitochondrial DNA test and submitted it as evidence that she was indeed Jewish.

Carmel explained to The Jerusalem Post the scientific rationale behind the claim.

Mitochondrial DNA, the genetic material present in cellular bodies called mitochondria, is inherited exclusively from a person’s mother, and therefore genetic markers in this DNA can be traced back many generations to determine a person’s maternal ancestors with a high degree of certainty.

According to the rabbi, experts in Jewish genealogy and history have determined that fully 40% of all Ashkenazi Jews are descended from just four Jewish women who left the Middle East over 1,000 years ago and settled in Europe.

According to the scientific report commissioned by Eretz Hemdah for its ruling, there is a certainty of at least 90% and up to 99% that someone bearing specific genetic markers in their mitochondrial DNA is descended from one of these women.

The report was authored by Prof. Karl Skorecki, a prominent geneticist at the Technion-Israel Institute of Technology and Rambam Medical Center in Haifa, and Dr. Shai Tzur, a fellow geneticist from Rambam.

Carmel insists the genetic test cannot be used to revoke someone’s Jewish status – even if they were found not to have the relevant genetic markers – since only 40% of Ashkenazi Jews have them, and someone without them likely comes from the other 60% of the extended Ashkenazi Jewish family. He also avers that there is “no such thing as a Jewish gene,” explaining that the mitochondrial genetic test simply determines ancestry, not Jewishness.

But for the immigrants who belong to the 40% of Ashkenazi Jews descended from the four women, the test could be a breakthrough in their efforts to prove their Jewish status if they lack other forms of conventional proof, such as Soviet-era documentation and witnesses.

Carmel says that because the test relates very specifically to one group of people descended from four individuals, it cannot be abused in the future as a prerequisite for determining Jewish status.

“There would be no point at all in trying to search for a Jewish gene because it doesn’t exist,” he said in response to the question of whether other genetic tests could be sought for Jewish status affirmation in the future.

Carmel and Ehrenreich have submitted their responsa and the genetic study to the Chief Rabbinate in the hope that the test could be accepted as valid by the rabbinical courts as a way of proving the Jewish status of citizens who are otherwise unable to do so.

However, Rabbi Seth Farber, head of the ITIM religious services advisory organization, expressed concern that the test could constitute the beginning of a slippery slope to greater reliance on scientific methods to prove Jewishness, which he said runs counter to traditional Jewish law.

“In traditional Jewish communities, principles in Jewish law such as the presumption that a person or family is Jewish are what allowed Jews from the next neighborhood or shtetl to marry each other, and created a sense of community and kinship,” Farber said.

He added that using scientific means to determine Jewishness could lead rabbinical judges to reject less precise but totally valid tools in Jewish law to establish someone’s Jewish status.

He pointed to a recent decision by the Supreme Rabbinical Court and its president, Sephardi Chief Rabbi Yitzhak Yosef, overturning the ruling of a lower court that had rejected a man’s Jewish status following a Jewish status clarification investigation.

Yosef ruled, according to the principle of majority, that since 75% to 80% of people undergoing such investigations are found to be Jewish, the man in question could also be presumed to be Jewish.

Farber said that genetic tests could threaten the use of such decision-making tools by rabbinical judges.

Carmel said in response to these issues that “While we appreciate Rabbi Farber’s concerns, our experience is that there are indeed many people who are truly unsure of their Jewish status and certainly unable to provide sufficient proof to be accepted by many rabbinical courts, and thus we would not want to deprive them of this opportunity to prove their Jewish identity. The concern of a slippery slope in this case seems less valid, because the mtDNA testing only applies to one segment of Ashkenazi Jews, and thus even if one does not turn up positive in the testing, all other current paths of proving Jewish identity are still open before him or her.”

Earth Had Life From Its Infancy

The Torngat Mountains in northeastern Canada are full of life. Reindeer graze on lichen, polar bears prowl the coastlines, and great whales swim in the offshore waters. Scientists patrol the land, too, looking for the oldest rocks on the planet, which were formed almost 4 billion years ago, when the Earth was just an infant world.

Back then, the landscape would have been very different. The Earth was a hellish place that had only just acquired a firm crust. Its atmosphere was devoid of oxygen, and it was regularly pelted with asteroids. There were no reindeer, whales, polar bears, or lichen. But according to new research, there was life.

In a rock formation called the Saglek Block, Yuji Sano and Tsuyoshi Komiya from the University of Tokyo found crystals of the mineral graphite that contain a distinctive blend of carbon isotopes. That blend suggests that microbes were already around, living, surviving, and using carbon dioxide from the air to build their cells. If the two researchers are right—and claims about such ancient events are always controversial—then this Canadian graphite represents one of the earliest traces of life on Earth.

The Earth was formed around 4.54 billion years ago. If you condense that huge swath of prehistory into a single calendar year, then the 3.95-billion-year-old graphite that the Tokyo team analyzed was created in the third week of February. By contrast, the earliest fossils ever found are 3.7 billion years old; they were created in the second week of March.

Those fossils, from the Isua Belt in southwest Greenland, are stromatolites—layered structures created by communities of bacteria. And as I reported last year, their presence suggests that life already existed in a sophisticated form at the 3.7-billion-year mark, and so must have arisen much earlier. And indeed, scientists have found traces of biologically produced graphite throughout the region, in other Isua Belt rocks that are 3.8 billion years old, and in hydrothermal vents off the coast of Quebec that are at least a similar age, and possibly even older.

“The emerging picture from the ancient-rock record is that life was everywhere,” says Vickie Bennett from Australian National University, who was not involved in the latest study. “As far back as the rock record extends—that is, as far back as we can look for direct evidence of early life, we are finding it. Earth has been a biotic, life-sustaining planet since close to its beginning.”

This evidence hinges on a quirk of chemistry. Carbon comes in two stable isotopes—carbon-12, which is extremely common, and carbon-13, which is rarer and slightly heavier. When it comes to making life, carbon-12 is the more pliable building block. It’s more reactive than its heavier cousin, and so easier to transform into molecules like carbohydrates and proteins.

So living organisms concentrate carbon-12 in their cells—and when they die, that signature persists. When scientists find graphite that’s especially enriched in carbon-12, relative to carbon-13, they can deduce that living things were around when that graphite was first formed. And that’s exactly what the Tokyo team found in the Saglek Block—grains of graphite, enriched in carbon-12, encased within 3.95-billion-year-old rock.

But are those graphite grains the same age? The rocks around them are metamorphic—they’ve been warped and transformed at extreme temperatures and pressures. During that process, and all the subsequent geological tumult that this region has experienced, it’s possible that much younger graphite somehow infiltrated the older rock, creating a false signal of early life.

To rule out that possibility, the Tokyo team looked at the structure of the graphite grains. The more orderly and crystalline those structures, the hotter the grains were when they formed. Based on that relationship, the team calculated the graphite was created at temperatures between 536 and 622 Celsius—a range that’s consistent with the temperatures at which the surrounding metamorphic rocks were transformed. This suggests that the graphite was already there when the rocks were heated and warped, and didn’t sneak in later. It was truly OG—original graphite.

There’s still room for doubt, though. Given how ancient these rocks are, and how much geological tumult they have experienced, it’s hard to fully exclude the possibility that the graphite got there later. Also, other processes that have nothing to do with living things could potentially change the ratio of carbon-12 and carbon-13. It’s concerning that the ratio varies a lot in the samples that the Tokyo team analyzed, says Andrew Knoll from Harvard University. But he also says that the team has been careful, and their combined evidence “makes a strong case that life existed on earth nearly 4 billion years ago.”

“The authors have done as many checks as they could for whether they are indeed analyzing 3.95-billion-year-old graphite rather than later contamination,” adds Elizabeth Bell, a geochemist from the University of California, Los Angeles. “They make a plausible case that the graphite is original.”

Bell herself found the oldest graphite that’s been measured to date. It lurked within a 4.1-billion-year-old zircon gemstone from Western Australia, and also contained a blend of isotopes that hinted at a biological origin. That discovery is also controversial, especially since the graphite was completely cut off from its source environment, making it hard to know the conditions in which it was formed.

Still, all of this evidence suggests Earth was home to life during its hellish infancy, and that such life abounded in a variety of habitats. Those pioneering organisms—bacteria, probably—haven’t left any fossils behind. But Sano and Komiya hope to find some clues about them by analyzing the Saglek Block rocks. The levels of nitrogen, iron, and sulfur in the rocks could reveal which energy sources those organisms exploited, and which environments they inhabited. They could tell us how life first lived.

NASA and Russia Partner Up for Crewed Deep-Space Missions

NASA and the Russian space agency Roscosmos have announced a new partnership for human exploration of the moon and deep space. Both agencies signed a joint statement on cooperation today (Sept. 27) at the 68th International Astronautical Congress in Adelaide, Australia.

The decision to partner with Russia on human missions to the moon and beyond came about as NASA continues to flesh out ideas for its “deep-space gateway” concept, a mission architecture designed to send astronauts into cislunar space — or lunar orbit — by the 2020s. Traveling to and from cislunar space will help NASA and its partners gain the knowledge and experience necessary to venture beyond the moon and into deep space.

A crewed mission to the moon and ultimately deep space would likely involve NASA’s gigantic new Space Launch System (SLS) rocket and the Orion space capsule. “This plan challenges our current capabilities in human spaceflight and will benefit from engagement by multiple countries and U.S. industry,” NASA officials said in a statement. [Photos: NASA’s Space Launch System for Deep Space Flights]

Roscosmos and NASA already work together with other space agencies around the world to run research projects aboard the International Space Station. Now the international partners will work together to build a miniature space station in lunar orbit – a type of infrastructure that could serve as a steppingstone for future crewed missions to Mars, NASA officials said.

In a separate statement, Roscosmos officials said the new partnership would “develop international technical standards … for the establishment of the station in the near-moon orbit.” According the Roscosmos, the partners also discussed the possibility of using a Russian superheavy rocket to complete construction of the orbital moon station.

“At the first stage, [the deep-space gateway] is supposed to use the American superheavy SLS in parallel with the domestic heavy rockets Proton-M and Angara-A5M,” Roscosmos officials said. “After the creation of the Russian superheavy rocket, it will also be used [for] the lunar orbital station.”

However, those plans are not concrete at this point, and NASA will continue to work with Roscosmos to research the best ways to transport astronauts to and from cislunar space.

“While the deep space gateway is still in concept formulation, NASA is pleased to see growing international interest in moving into cislunar space as the next step for advancing human space exploration,” Robert Lightfoot, NASA’s acting administrator, said in a statement.

“Statements such as this one signed with Roscosmos show the gateway concept as an enabler to the kind of exploration architecture that is affordable and sustainable,” Lightfoot added.

Meanwhile, NASA is also asking the private space industry to contribute to the deep-space gateway. The agency has already awarded contracts for deep-space habitat designs to Bigelow Airspace, Lockheed Martin, Orbital ATK and others.

Email Hanneke Weitering at hweitering@space.com or follow her @hannekescience. Follow us @SpacedotcomFacebook and Google+. Original article on Space.com.

Giant wombatlike creatures migrated across Australia 300,000 years ago

http://www.sciencemag.org/news/2017/09/giant-wombatlike-creatures-migrated-across-australia-300000-years-ago

 

About 300,000 years ago, herds of rhino-sized creatures migrated across the floodplains of east-central Australia, mimicking the treks that zebras and antelopes make across Africa’s Serengeti today. But these migrants weren’t majestic, long-limbed grazers. Instead they were car-sized relatives of today’s short and stocky wombat. Evoked by a new analysis of a fossil tooth of the long-extinct animal, called Diprotodon, the scenario would be the only known seasonal mass migration among marsupials and their close kin.

The team’s findings are “pretty convincing to me,” says Anthony Stuart, a vertebrate paleontologist at Durham University in the United Kingdom. “For the first time, someone has demonstrated that Diprotodon migrated seasonally.” Similar analyses of fossils of other members of the same ancient ecosystem may reveal that multiple species participated in the ancient migrations, scientists say.

Like many parts of the world during the most recent ice ages (the last of which ended about 12,000 years ago), Australia had its share of weird giant animals, including a supersized relative of the Komodo dragon, today’s largest land lizard. But most of the continent’s so-called megafauna were marsupials. The largest was Diprotodon, 1.8 meters tall, nearly 3000 kilograms in weight, and named for its dentition—roughly translated from Greek, Diprotodon means “two forward teeth.” That pair of teeth, like the incisors of modern-day rabbits, never stopped growing, says Gilbert Price, a vertebrate paleontologist at the University of Queensland in Brisbane, Australia. As they grew, they incorporated trace elements dissolved in the water that the creature drank, as well as carbon, oxygen, and other elements from the food it ate. Because the isotopic makeup of those elements varies from place to place, Diprotodon’s steadily growing teeth became, in essence, a chronicle of its movements, in layers akin to tree rings.

By providing your email address, you agree to send your email address to the publication. Information provided here is subject to Science’s Privacy Policy.

“You’ve heard of the old saying ‘You are what you eat?’” Price asks. “As it turns out, you are whereyou eat, too.”

He and his colleagues took dozens of small samples from a 30-centimeter-long Diprotodon incisor. Using radioactive dating techniques, the team found that the creature lived about 300,000 years ago. Samples drilled from evenly spaced sites along the tooth also revealed cyclic variations in isotope ratios, including strontium, carbon, and oxygen, suggesting that this animal migrated about 200 kilometers each year, Price and his colleagues report today in the Proceedings of the Royal Society B. As a comparison, annual mass migrations of animals across the Serengeti plains of Africa cover about 800 kilometers.

The regular variation in isotope ratios suggests that rather than wandering at random from site to site, Diprotodon made the same round trip each year, following seasonal shifts in vegetation and rainfall. It’s the first time any marsupial living or extinct has been shown to migrate regularly, the team notes.

Modern-day marsupials such as red kangaroos do roam to find ephemeral food sources, says Stephen Wroe, a paleo-ecologist at the University of New England in Armidale, Australia. But those rovings are random, not regular, as Price and his colleagues propose is the case for Diprotodon. “That’s what makes this team’s results so interesting, and it suggests that the climate in the region at the time was more predictable than it is now,” Wroe says.

The new analysis “is an elegant example of how to use the geochemistry of a fossil to infer the behavior and movement of an ancient creature,” says Henry Fricke, an isotope geochemist at Colorado College in Colorado Springs. “Where an animal died doesn’t necessarily tell you where it spent its time while alive.”