Connect with us

Science

Yukon gold miner unearths a mummified Ice Age wolf pup – Ars Technica

Published

 on


Enlarge / The puppy’s remains are dried out but mostly intact thanks to being buried in permafrost.

This Ice Age wolf puppy doesn’t look much like a fearsome predator, what with her tiny puppy teeth and soft little ears. According to her DNA, however, the mummified puppy, named Zhùr, came from a population that’s among the ancestors of all modern wolves. Canada’s permafrost freeze-dried her remains shortly after her death around 57,000 years ago.

“She’s the most complete wolf mummy that’s ever been found. She’s basically 100 percent intact—all that’s missing are her eyes,” said Des Moines University paleontologist Julie Meachen.

Puppy surprise

In July 2016, miner Neil Loveless of Favron Enterprises was searching for gold in Alaska’s famed Klondike gold fields. He was water-blasting the frozen mud along the banks of Last Chance Creek. It’s a process called “hydraulic thawing,” meant to thaw and soften the frozen permafrost so miners can search for gold in the streambed deposits, an approach called placer mining. But Loveless found something far stranger and even more interesting than Klondike gold: a frozen, mummified wolf puppy.

“We thank [Loveless] for his keen eye spotting Zhùr as she was melting out of the permafrost, ensuring she was kept safe in a freezer, and then reporting the discovery to Yukon Paleontology,” wrote Meachen and her colleagues in a recent paper in the journal Current Biology. Studying Pleistocene wildlife in the Yukon means working with gold-mining companies, whose workers might be the first to spot something like Zhùr. Scientists like Meachen also work very closely with the people who have called this region home for thousands of years, like the Tr’ondëk Hwëch’in First Nation.

Members of the group gave the puppy her name, Zhùr, which means “wolf” in the Hän language. Zhùr is a culturally significant find for the Tr’ondëk Hwëch’in, but they were also interested in how much the frozen puppy could teach us about Pleistocene wolves. The First Nation agreed to display the mummy at the Yukon Beringia Interpretive Center in Whitehorse, where she has been cleaned, conserved, and studied.

“We are grateful for the partnership with Tr’ondëk Hwëch’in in our shared role in protecting and preserving heritage resources in the Klondike,” wrote Meachen and her colleagues.

Taking tiny samples from a few of Zhùr’s incredibly well-preserved hair follicles, Meachen and her colleagues radiocarbon dated the frozen puppy and studied the chemical isotopes in her body, which offered clues about what she ate and the climate in which she lived. They also sequenced her mitochondrial DNA, the genetic material passed down directly from mother to offspring.

The ancestors of modern wolves

Zhùr probably lived around 57,000 years ago, but it took three different dating methods to figure that out.

Radiocarbon dating could only tell Meachen and her colleagues that the mummy was older than 50,000 years. The puppy’s genome suggested that she’d lived sometime between 75,000 and 56,000 years ago, based on the rate at which wolf DNA collects mutations over time. And the oxygen isotopes in her body suggested that she had lived during the relatively warm period of Marine Isotope Stage 3, when warmer conditions led to smaller ratios of the isotope oxygen-18 in marine sediment cores—and in Zhùr’s body. MIS 3 spanned a period 57,000 to 29,000 years ago.

All of those possible dates overlapped at one point: 57,000 to 56,000 years ago. At the time, sea levels were much lower than today, and a region of dry land called Beringia connected Siberia and Canada. Animals moved freely back and forth between the continents, which is why Pleistocene wolves unearthed across Eurasia and North America are all so closely related. Zhùr’s mitochondrial DNA fit right into that group of closely related animals, or clade, with a common ancestor that lived between 86,000 and 67,500 years ago.

Zhùr and her clade are the ancestors of every wolf in the world (except possibly the high-altitude Himalayan wolves, which have apparently been doing their own thing for hundreds of thousands of years, according to a study earlier in 2020).

But because mitochondrial DNA gets passed down directly from mother to puppy, Meachen and her colleagues could tell that Zhùr wasn’t a direct ancestor of the wolves that roam the Klondike today. Sometime in the last 56,000 years or so, the Klondike wolf population died out or left the area, and another group of wolves—one less closely related to Zhùr—replaced it. At the moment, there’s not enough data to tell if the newcomers drove off, outcompeted, or just absorbed Zhùr’s relatives, but the puppy’s DNA hints at an interesting story yet to be explored.

Wolves eat fish, too

If Zhùr couldn’t tell Meachen and her colleagues exactly what happened to a whole population of Klondike wolves, she could at least tell quite a bit of her own story. Based on how her bones had developed, the puppy was about 7 weeks old when she died. Since modern wolves in the area usually give birth in early summer, that means Zhùr probably died in July or early August, around the same time Loveless washed her out of the permafrost 57,000 years later.

By then, Zhùr’s mother had probably weaned her pups from milk and started bringing them real food. Modern wolf puppies start eating solid food at around 5 or 6 weeks old. In Zhùr’s case, that seems to have included a lot of fish, according to the amount of the isotope nitrogen-15 in her body. Nitrogen isotopes offer clues about how far up the food chain an animal might have been and whether more of its food came from land or water.

Given all the fish, the puppy’s breath must have been atrocious. “Normally, when you think of wolves in the Ice Age, you think of them eating bison or musk oxen or other large animals on land,” said Meachen. “One thing that surprised us was that she was eating aquatic resources, particularly salmon.”

Modern wolves in the Alaskan interior have been known to chow down on fish, at least in seasons when they’re readily available. And Zhùr’s den wasn’t far from the Klondike River, where Chinook salmon spawn today. The fish swim up the Yukon River to the Klondike, where they would have been a veritable buffet for a mother wolf looking to feed her pups.

How to freeze-dry an Ice Age predator

Obviously things didn’t end well for Zhùr, or we wouldn’t have a ridiculously adorable canid ice mummy to study today. Her burial can offer a few clues about her untimely end and her uncannily good preservation over the intervening millennia. She must have died in just the right conditions and been buried quickly—a rare combination. “The animal has to die in a permafrost location, where the ground is frozen all the time, and they have to get buried very quickly, like any other fossilization process,” said Meachen.

Animals that get killed by predators don’t tend to form perfectly preserved ice mummies, and animals that die from sickness or exposure also don’t tend to get buried quickly enough to freeze and mummify. And isotopic analysis suggests the puppy was well-nourished, so whatever happened, she probably wasn’t sick and definitely wasn’t starving.

Meachen and her colleagues think Zhùr’s den collapsed, killing her instantly and burying the remains in the freezing ground. “We feel a bit better knowing the poor little girl didn’t suffer for too long,” said Meachen.

There’s another question that Zhùr will never be able to answer, however: why was she alone in the den? Wolf mothers usually have four to six puppies at a time, but only Zhùr was buried alongside Last Chance Creek; no sign of her mother or littermates has turned up. “It could be that she was an only pup, or the other wolves weren’t in the den during the collapse,” said Meachen. “Unfortunately, we’ll never know.”

A cautionary tail

Permafrost mummies of large mammals, like mammoths, bears, and even wolves, are rare finds for paleontologists. But smaller ones, like ground squirrels and ferrets, turn up more often in places like Siberia and the Yukon. Meachen and her colleagues speculate that animals who lived in burrows or dens, including wolf pups, may have had better odds of getting preserved in the permafrost, especially if they died in cave-ins.

Even large permafrost mummy finds are getting more common, though. A cave bear emerged from the Siberian permafrost earlier this year, and it’s one of several recent finds. “One small upside of climate change is that we’re going to find more of these mummies as permafrost melts,” said Meachen. “That’s a good way for science to reconstruct that time better, but it also shows us how much our planet is actually warming.”

Current Biology, 2020 DOI: 10.1016/j.cub.2020.11.011 (About DOIs).

Let’s block ads! (Why?)



Source link

Continue Reading

Science

Breathtaking NASA Image Shows a Magical ‘Sea of Dunes’ on Mars

Published

 on

On Thursday, NASA released a stunning photo of a sea of dunes on Mars.

It also shows wind-sculpted lines surrounding Mars’ frosty northern polar cap.

The section captured in the shot represents an area that is 31 kilometers (19 miles) wide, NASA said. The sea of dunes, however, actually covers an area as large as Texas.

The photo is a false color image, meaning that the colors are representative of temperatures. Blue represents cooler climes, and the shades of yellow mark out “sun-warmed dunes,” the US space agency wrote.

Sea of dark dunes surrounds Mars’ northern polar cap.(NASA/JPL-Caltech/ASU)

The photo is made of a combination of images captured by the Thermal Emission Imaging System instrument on the Mars Odyssey orbiter, NASA wrote.

Captured during the period from December 2002 to November 2004, the breathtaking images have been released to mark the 20th anniversary of Odyssey.

The Mars Odyssey orbiter is a robotic spacecraft circling Mars that uses a thermal imager to detect evidence of water and ice on the planet.

It was launched in 2001, making it the longest-working Mars spacecraft in history.

Source:- ScienceAlert

Source link

Continue Reading

Science

Humans actually hunted large animals and ate mostly meat for 2 millions years: study – CTV News

Published

 on


TORONTO —
Despite a widespread belief that humans owe their evolution to the dietary flexibility in eating both meat and vegetables, researchers in Israel suggest that early humans were actually apex predators who hunted large animals for two million years before they sought vegetables to supplement their diet.

In a study recently published in the American Journal of Physical Anthropology, academics from Tel Aviv University in Israel and the University of Minho in Portugal examined modern biology to determine if stone-age humans were specialized carnivores or generalist omnivores.

“So far, attempts to reconstruct the diet of Stone-Age humans were mostly based on comparisons to 20th century hunter-gatherer societies,” one of the study’s authors, Miki Ben-Dor, a researcher at Tel Aviv University, said in a press release.

“This comparison is futile, however, because two million years ago hunter-gatherer societies could hunt and consume elephants and other large animals – while today’s hunter gatherers do not have access to such bounty.”

Instead, the researchers looked at approximately 400 previous scientific studies on human anatomy and physiology as well as archeological evidence from the Pleistocene period, or “Ice Age” period, which began about 2.6 million years ago, and lasted until 11,700 years ago.

“We decided to use other methods to reconstruct the diet of Stone-Age humans: to examine the memory preserved in our own bodies, our metabolism, genetics and physical build,” Ben-Dor said.

“Human behaviour changes rapidly, but evolution is slow. The body remembers.”

They discovered 25 lines of evidence from the studied papers on human biology that seem to show that earlier Homo sapiens were apex predators at the top of the food chain.

For example, the academics explained that humans have a high acidity in their stomachs when compared to omnivores or even other predators, which is important for consuming animal products.

“Strong acidity provides protection from harmful bacteria found in meat, and prehistoric humans, hunting large animals whose meat sufficed for days or even weeks, often consumed old meat containing large quantities of bacteria, and thus needed to maintain a high level of acidity,” Ben-Dor said.

Another piece of evidence, according to the study, is the structure of human fat cells.

“In the bodies of omnivores, fat is stored in a relatively small number of large fat cells, while in predators, including humans, it’s the other way around: we have a much larger number of smaller fat cells,” Ben-Dor said.

HUNTING EXPERTS

In addition to the evidence they collected by studying human biology, the researchers said archeological evidence from the Pleistocene period supports their theory.

In one example, the study’s authors examined stable isotopes in the bones of prehistoric humans as well as their hunting practices and concluded these early humans specialized in hunting large and medium-sized animals with high fat content.

“Comparing humans to large social predators of today, all of whom hunt large animals and obtain more than 70% of their energy from animal sources, reinforced the conclusion that humans specialized in hunting large animals and were in fact hypercarnivores,” the academics noted.

Ben-Dor said Stone-Age humans’ expertise in hunting large animals played a major role in the extinction of certain large animals, such as mammoths, mastodons, and giant sloths.

“Most probably, like in current-day predators, hunting itself was a focal human activity throughout most of human evolution. Other archeological evidence – like the fact that specialized tools for obtaining and processing vegetable foods only appeared in the later stages of human evolution – also supports the centrality of large animals in the human diet, throughout most of human history,” he said.

This is not to say, however, that humans during this period didn’t eat any plants. Ben-Dor said they also consumed plants, but they weren’t a major component of their diet until the end of the era when the decline of animal food sources led humans to increase their vegetable intake.

Eventually, the researchers said humans had no choice but to domesticate both plants and animals and become farmers.

Ran Barkai, one of the study’s authors and a professor at Tel Aviv University, said their findings have modern-day implications.

“For many people today, the Paleolithic diet is a critical issue, not only with regard to the past, but also concerning the present and future. It is hard to convince a devout vegetarian that his/her ancestors were not vegetarians, and people tend to confuse personal beliefs with scientific reality,” he said. 

Let’s block ads! (Why?)



Source link

Continue Reading

Science

Marimaca Copper: First Drill Hole Intersects Broad Zone of Sulphide Copper Mineralization at Marimaca – Junior Mining Network

Published

 on


VANCOUVER, British Columbia, April 07, 2021 (GLOBE NEWSWIRE) — Marimaca Copper Corp. (“Marimaca Copper” or the “Company”) (TSX: MARI) is pleased to announce the assay results of the first drill hole of a five-hole program targeting extensions of sulphide mineralization below the Company’s flagship Marimaca Oxide Deposit (“MOD”). Drilling encountered a broad zone of chalcopyrite and minor chalcocite, indicating potential for economic sulphide mineralization.

Highlights

  • Drill hole MAR-125 intersected 116m (expected approximate true width) at an average grade of 0.51% CuT from 162m, including two higher grade zones of:
    • 20m with an average grade of 0.77% CuT from 162m; and
    • 42m with an average grade of 0.92% CuT from 236m.
  • Intersection represents a significantly broader zone of mineralization than anticipated from earlier, nearby, sulphide drilling intersections
  • First drill hole of an initial five-hole campaign to test for extensions of mineralization at depth
    • First hole designed to extend mineralization closer to sulphide zones identified in historical drilling
    • Remaining four holes designed to test the limits of mineralization with step outs of approximately 300m at depth and between 400m and 700m along strike to the north and south of the first hole
  • Sulphide drilling to be completed shortly, with assay results on remaining holes expected by the end of April 2021
  • In response to escalating COVID situation in Chile, the Company has initiated a break in drilling which is not expected to impact the original target of testing all identified targets by the end of 1H 2021.

Sergio Rivera, VP Exploration of Marimaca Copper, commented:

“The results of the first hole of this initial campaign are extremely pleasing, exceeding both the widths and grades we had projected for this zone based on earlier drilling completed nearby. The broad intercept of chalcopyrite mineralization shows good continuity downhole, with potentially economic grades, especially at the bottom of the intercept.

“The drilling has also provided additional geological information, which we are using to refine our understanding of the controls of mineralization and to inform future drillhole locations, targeting mineralized extensions at depth and along strike.

“The next four holes are significant step outs from the known mineralized zones outside of the Mineral Resource Estimate area and are designed to test the limits of the mineralized body, both at depth and along strike. The second hole will be collared approximately 350m to the east of MAR-125, targeting mineralization up to 300m below the current deepest mineralization. The third, fourth and fifth holes will be located between 400m and 700m to the north and south of MAR-125, aiming to test for extensions along strike.

“This first hole has provided encouragement that there is potential for economically interesting sulphide mineralization at Marimaca, while the next four drill holes are designed to better delineate the tonnage potential of this.”

Discussion of Campaign Objectives and Results

The current five-hole drilling campaign at the Marimaca Copper Project is designed to test for extensions to mineralization below the MOD. Based on the structural controls of the mineralization, the results of previous geophysical campaigns and earlier drilling, which extended beyond the current Mineral Resource Estimate (“MRE”) area, the Company believes there is the potential for extensions of the mineralized body at depth across the full strike length of the MOD. All drill holes will be drilled at an azimuth of 270o and at -60o, roughly perpendicular to the north-south striking, easterly dipping mineralizing structures. Intercepts should, therefore, be relatively close to the true width of the mineralization.

The first drill hole (MAR-125) encountered a broad zone of dominantly chalcopyrite mineralization with some pyrite and minor chalcocite over a down hole width (expected to be equivalent to approximate true width) of 116m with an average grade of 0.51% CuT. This includes two zones of higher-grade mineralization including 20m with an average grade of 0.77% CuT and 42m with an average grade of 0.92% CuT at the end of the mineralized intercept. The hole was collared to test mineralization approximately 100m to the east of the earlier hole ATR-82, which intersected 44m of sulphide copper mineralization with an average grade of 1.05% CuT, and 200m and 300m east of holes ATR-93 and ATR-94 respectively, which both intersected mineralization with true widths of around 40m with average grades above 1.0% CuT. MAR-125 has demonstrated an extension to this higher-grade mineralization and provides further areas to target for follow up drilling.

MAR-125 is located in the center of the current MRE area, proximal to a zone of relatively high-grade sulphide mineralization intercepted in several drill holes over widths of between 30m and 50m. The remaining four drill holes have been located to test the limits of the mineralization by stepping out significantly at depth and along strike beyond the current MRE area. The collar of the second hole, MAS-03, is located approximately 100m to the south and 350m to the east of MAR-125 and is aimed to intersect mineralization approximately 300m below MAR-125. MAS-02 and MAS-04, located approximately 400m and 700m, respectively, south of MAR-125, and are planned as significant step outs along strike, targeting the conductivity high noted in the IP survey completed across the MOD

Figure 2

Sampling and Assay Protocol

True widths cannot be determined with the information available at this time. Marimaca Copper RC holes were sampled on a 2-metre continuous basis, with dry samples riffle split on site and one quarter sent to the Andes Analytical Assay preparation laboratory in Calama and the pulps then sent to the same company laboratory in Santiago for assaying. A second quarter was stored on site for reference. Samples were prepared using the following standard protocol: drying; crushing to better than 85% passing -10#; homogenizing; splitting; pulverizing a 500-700g subsample to 95% passing -150#; and a 125g split of this sent for assaying. All samples were assayed for CuT (total copper), CuS (acid soluble copper) by AAS. A full QA/QC program, involving insertion of appropriate blanks, standards and duplicates was employed with acceptable results. Pulps and sample rejects are stored by Marimaca Copper for future reference.

Qualified Person

The technical information in this news release, including the information that relates to geology, drilling and mineralization was prepared under the supervision of, or has been reviewed by Sergio Rivera, Vice President of Exploration, Marimaca Copper Corp, a geologist with more than 36 years of experience and a member of the Colegio de Geólogos de Chile and of the Institute of Mining Engineers of Chile, and who is the Qualified Person for the purposes of NI 43-101 responsible for the design and execution of the drilling program.

Mr. Rivera confirms that he has visited the Marimaca Project on numerous occasions, is responsible for the information contained in this news release and consents to its publication.

Contact Information
For further information please visit www.marimaca.com or contact:

Tavistock
+44 (0) 207 920 3150
Jos Simson/Emily Moss 
This email address is being protected from spambots. You need JavaScript enabled to view it. 

Forward Looking Statements

This news release includes certain “forward-looking statements” under applicable Canadian securities legislation. These statements relate to future events or the Company’s future performance, business prospects or opportunities. Forward-looking statements include, but are not limited to, the impact of a rebranding of the Company, the future development and exploration potential of the Marimaca Project. Actual future results may differ materially. There can be no assurance that such statements will prove to be accurate, and actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements reflect the beliefs, opinions and projections on the date the statements are made and are based upon a number of assumptions and estimates that, while considered reasonable by Marimaca Copper, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Many factors, both known and unknown, could cause actual results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements and the parties have made assumptions and estimates based on or related to many of these factors. Such factors include, without limitation: risks related to share price and market conditions, the inherent risks involved in the mining, exploration and development of mineral properties, the uncertainties involved in interpreting drilling results and other geological data, fluctuating metal prices, the possibility of project delays or cost overruns or unanticipated excessive operating costs and expenses, uncertainties related to the necessity of financing, the availability of and costs of financing needed in the future as well as those factors disclosed in the Company’s documents filed from time to time with the securities regulators in the Provinces of British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland and Labrador. Accordingly, readers should not place undue reliance on forward-looking statements. Marimaca Copper undertakes no obligation to update publicly or otherwise revise any forward-looking statements contained herein whether as a result of new information or future events or otherwise, except as may be required by law.


Let’s block ads! (Why?)



Source link

Continue Reading

Trending