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G24 INSTA NWT_Animals NWT_Biology Research SCI TECH

Study suggests narwhals and beluga whales experience menopause

A team of scientists discovered that narwhals and beluga whales experience menopause, which brings the total number of species known to experience the process to five. Humans aside, the species known to experience menopause all belong to the toothed whale parvorder.

“For menopause to make sense in evolutionary terms, a species needs both a reason to stop reproducing and a reason to live on afterwards,” said Sam Ellis of the University of Exeter, first author of the study. “In killer whales, the reason to stop comes because both male and female offspring stay with their mothers for life—so as a female ages, her group contains more and more of her children and grandchildren.”

“This increasing relatedness means that, if she keeps having young, they compete with her own direct descendants for resources such as food,” he added.

“The reason to continue living is that older females are of great benefit to their offspring and grand-offspring. For example, their knowledge of where to find food helps groups survive.”

More than four decades of intense study has documented the existence of menopause in killer whales.

“It’s hard to study human behaviour in the modern world because it’s so far removed from the conditions our ancestors lived in,” said Darren Croft, senior author of the study. “Looking at other species like these toothed whales can help us establish how this unusual reproductive strategy has evolved.”

Despite the fact that many individuals in various species fail to reproduce later in life, the team looked for evidence that suggested an “evolved strategy” where females had a post-reproductive lifespan.

The findings were published in Scientific Reports.

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Archaeology NWT_Biology SCI TECH

Experts say ‘alien’ mummy study was flawed, crossed ethical line

Experts are now saying that a 2013 paper by Stanford University immunologist Garry Nolan, which examined the Atacama Mummy, was both flawed and unethical. The study examined the mummy and determined that—contrary to rumors—it was not of extraterrestrial origin, and its strange features were the result of genetic mutations.

But the Chilean National Monuments Council quickly suggested that the mummy’s remains might have been obtained through grave robbing and illegal smuggling. Not only that, many scientists suggested the study was inappropriate.

Now, a new paper headed by a led by Sian Halcrow from the University of Otago, New Zealand claims that the research is riddled with misinterpretations and errors, and suggests there is “no evidence” of the skeletal anomalies described in the original paper.

“We are experts in developmental human anatomy and archaeology, and the mummy looks normal for a fetus around 15-16 weeks gestation,” said Kristina Killgrove, a co-author of the new study. “To the average person, I understand how Ata could look odd, but that’s because the average person doesn’t see developing fetuses or mummies.”

“Unfortunately, there was no scientific rationale to undertake genomic analyses of Ata because the skeleton is normal, the identified genetic mutations are possibly coincidental, and none of the genetic mutations are known to be strongly associated with skeletal pathology that would affect the skeleton at this young age,” Halcrow said.

“Given the fact that the mummified fetus was clearly human, the geneticists did not need to do further testing,” Killgrove said. “But more problematic than that was, once they did test and find it was human, they didn’t immediately stop and question the forensic or archaeological ethics.”

“Whether the fetus mummy was ancient or more recent, Chile requires permits for this sort of testing,” she added. “We believe that these geneticists should have involved a specialist in developmental skeletal biology from the beginning as they would not have made rookie mistakes. But we also want to use this as a cautionary tale going forward—genetics experts need to be informed about ancient and modern laws and ethics surrounding testing.”

The original paper was published in Genome Research.

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NWT_Animals NWT_Biology SCI TECH

Extinct cave bear DNA discovered in living bears

A new study discovered that approximately 0.9 to 2.4 percent of living brown bears’ DNA can be traced back to the extinct cave bears species, which died out approximately 24,000 years ago.

The discovery is the second time that scientists have discovered the DNA of extinct ice-age creatures in living relatives.

“By any standard definition, [cave bears] are extinct, but it doesn’t mean that their gene pool is erased, because they continue to live on in the genomes of these living animals,” said Axel Barlow, a postdoctoral researcher at the University of Potsdam and one of the lead authors of the study.

The data also suggests that some species interbreed regularly. For example, the DNA of Tibetan cattle and yak exhibit signs of interbreeding.

“The old-fashioned idea of a species [is that] it’s reproductively isolated from other species,” said Rasmus Nielsen, a geneticist at the University of California who wasn’t involved in the study. “This paper is a part of a series of papers that have been saying that worldview really is wrong.”

And since animal genomes are so massive, there’s plenty of room for variation in some genes. Just by chance alone, similar genes located in distantly related animals can appear similar, and identical genes in closely related animals can appear different.

“If we get an overabundance of genome positions where cave bears and brown bears are showing more similarity to each other than to polar bears, then something else must have happened,” Barlow said. “And that something is hybridization between the two species.”

The findings were published in Nature Ecology and Evolution.

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NWT_Biology SCI TECH

Eating early dinners could reduce cancer risk, study says

A new study reveals links between the time of evening that people eat their dinner and their risk of developing numerous cancers, such as prostate and breast cancer—both of which are two of the biggest killers in women and men.

The findings shed light on the cancer risks outside of what is common knowledge, such sun exposure and tobacco use.

“Modern life involves mistimed sleeping and eating patterns that in experimental studies are associated with adverse health effects,” the researchers said. “We assessed whether timing of meals is associated with breast and prostate cancer risk taking into account lifestyle and chronotype, a characteristic correlating with preference for morning or evening activity.”

Most of the research focuses on the amount of time that passes between a person’s last meal and their bedtime. People who eat prior to 9 pm. or a couple of hours before sleeping lower their risk of developing cancer. Specifically, the study suggests that these people decrease their cancer risk by 20% compared to people who eat dinner after 10 p.m. or right before going to bed.

The study examined the eating and sleeping habits of thousands of people. The data suggests that early dinners are beneficial for decreasing common types of cancer, although the exact reason for this connection is still not known.

For now, the team believes that circadian rhythm, which refers to patterns of sleep and daily activity that humans have exhibited over thousands of years, plays a strong role.

The findings were published in the International Journal of Cancer.

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HEALTH NWT_Biology Research SCI TECH

Researchers discover way to turn any blood type to universal O

A team of Canadian researchers might have discovered a way to turn any blood type to the universal O, which would eliminate the need for compatibility between blood donors and recipients.

Human blood has four types: AB, A, B, and O. They are distinguished by tiny sugar molecules located on the surface of red blood cells. When types are incompatible, the body initiates a dangerous immune reaction against the cells of the foreign blood.

“In the lab, we tossed around various ideas about where there might be bacteria that would degrade blood,” said biochemist Stephen Withers. “One thinks of things like the leech gut or the mosquito gut, but those are probably a little hard to access.”

The team examined around 20,000 different DNA samples to determine the best enzyme to cut off blood cell antigens necessary for the process.

“This work is very promising,” said Dana Devine, chief scientist at Canadian Blood Services. “The type of blood donated will likely never be exactly matched to the demand for specific blood groups, but this new technology offers an opportunity to create a ‘workaround’ for the disproportionate demand for O blood by turning the excess inventory of other blood groups into group O.”

“It can cleave approximately 30 times more quickly from the previous best candidate that was published a while back, when we did a side-by-side comparison of the two,” Withers said.

He believes that the success of his projects hinges on new techniques in metagenomics that were not available to previous researchers.

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NWT_Animals NWT_Biology SCI TECH

Scientists solve mystery behind bird egg shape

A team of scientists just discovered why guillemot eggs have their strangle shape—a centuries-old mystery that has stumped biologists for hundreds of years.

A previous theory suggested that the egg’s pointed shape evolved to aid its arc-like rolling motion in order to prevent it from rolling off of a cliff while being incubated on a cliff ledge. Now, a new study reveals that the shape actually evolved to keep the egg in place and prevent it from rolling away at all.

“Guillemots are one of the most fascinating species of birds that we have in the UK, however they are often overshadowed by their neighbour, the puffin,” said Tim Birkhead of the University of Sheffield. “This is mostly because people love the way puffins look, but in terms of behaviour, guillemots are much more interesting for nature enthusiasts to watch.”

“Apart from looking cute, Puffins don’t really do much at the colony,” he added. “In contrast, watching guillemots is like watching nature’s very own soap opera: a never-ending mix of marital affection, infidelity and strife. And, in terms of keeping a health check on the oceans, you can’t beat guillemots since we can survey their numbers, survival and breeding success more easily accurately than almost any other seabird.”

The groundbreaking study dispels the old belief that the pointed eggs evolved to promote an arc-like rolling motion and highlights the fascinating nature of guillemot eggs, which are considered to be one of the most beautiful eggs in the world.

The findings were published in The Auk.

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NWT_Biology Physics Research SCI TECH

Scientists discover first evidence of matter-matter coupling

A new study from Rice University scientists revealed the first evidence of Dicke cooperativity in a matter-matter system. The findings could help evolve our understanding of quantum magnetism and spintronics.

The team used a magnetic field to induce cooperativity among spins within a crystalline compound created primarily from erbium and iron.

“This is an emerging subject in condensed matter physics,” Kono said. “There’s a long history in atomic and molecular physics of looking for the phenomenon of ultrastrong cooperative coupling. In our case, we’d already found a way to make light and condensed matter interact and hybridize, but what we’re reporting here is more exotic.”

Dicke cooperativity occurs when incoming radiation causes a group of atomic dipoles to couple, much like gears within a motor that don’t touch.

“Dicke was an unusually productive physicist,” Kono said. “He had many high-impact papers and accomplishments in almost all areas of physics. The particular Dicke phenomenon that’s relevant to our work is related to superradiance, which he introduced in 1954. The idea is that if you have a collection of atoms, or spins, they can work together in light-matter interaction to make spontaneous emission coherent. This was a very strange idea.”

“The interaction we’re talking about is really atomistic,” Kono concluded. “We show two types of spin interacting in a single material. That’s a quantum mechanical interaction, rather than the classical mechanics we see in light-matter coupling. This opens new possibilities for not only understanding but also controlling and predicting novel phases of condensed matter.”

The findings were published in Science.

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NWT_Biology Research SCI TECH

Evolution might favor ‘survival of the laziest,’ study says

A new study of fossil and extant gastropods and bivalves from the Atlantic Ocean suggests that individual, species, and communities of species can use laziness as a survival strategy.

The study examined 299 species from approximately 5 million years through the mid-Pliocene to the present. In particular, it examined the metabolic rates of the species and found that higher metabolic rates were predictive of the likelihood of extinction.

“We wondered, ‘Could you look at the probability of extinction of a species based on energy uptake by an organism?'” said Luke Strotz, lead author of the paper. “We found a difference for mollusk species that have gone extinct over the past 5 million years and ones that are still around today. Those that have gone extinct tend to have higher metabolic rates than those that are still living. Those that have lower energy maintenance requirements seem more likely to survive than those organisms with higher metabolic rates.”

Continued research will determine just how much metabolic rate influences the extinction rates of other species of animals.

“We see these results as generalizable to other groups, at least within the marine realm,” Strotz said. “Some of the next steps are to expand it out to other clades, to see if the result is consistent with some things we know about other groups.”

“There is a question as to whether this is just a mollusk phenomenon?” he continued. “There’s some justification, given the size of this data set, and the long amount of time it covers, that it’s generalizable. But you need to look—can it apply to vertebrates? Can it apply on land?”

The findings were published in the Proceedings of the Royal Society B.

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Archaeology NWT_Biology SCI TECH

Human prehistoric ancestors mated with each other, study says

A new study reveals an inter-species prehistoric human ancestor with a Denisovan father and Neanderthal mother. The unique lovechild was named Denisova and was at least 13 years old when she died of unknown causes.

“There was earlier evidence of interbreeding between different hominin, or early human, groups,” said Vivian Slon, lead author of the study. “But this is the first time that we have found a direct, first-generation offspring.”

The team analyzed the remains of a bone fragment discovered in 2012 by Russian archaeologists, which revealed chromosomes that were half Denisovan and half Neanderthal. Both of these early human species split apart approximately 400,000 to 500,000 years ago.

“I initially thought that they must have screwed up in the lab,” said senior author Svante Paabo.

Less than two dozen human genomes from before 40,000 years ago have been sequenced. Not only that, but the chances of discovering a half-and-half hybrid is already very small.

“The very fact that we found this individual of mixed Neanderthal and Denisovan origins suggests that they interbred much more often than we thought,” Slon said.

“They must have quite commonly had kids together, otherwise we wouldn’t have been this lucky,” Paablo agreed.

“Part of the story of these groups is that they may simply have been absorbed by modern populations,” he added. “The modern humans were more numerous, and the other species might have been incorporated.”

The study highlights the possibility that Denisovans and Neanderthals might have mated more if not for the fact that the former typically settled in Europe.

The findings were published in Nature.

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Archaeology NWT_Biology Research SCI TECH

Laziness likely helped kill off Homo erectus, study says

A new study examining archaeological research suggests that the extinct species of primitive humans, Homo erectus, met their end in part because they were “lazy.”

The conclusion stems from an archaeological excavation of an ancient population of the species in the Arabian Peninsula that lived during the Early Stone Age. The data suggests that they used “least-effort strategies” to create tools and gather resources.

In combination with an inability to adapt to an evolving climate, this “laziness” most likely played a role in the species’ extinction.

“They really don’t seem to have been pushing themselves,” said Ceri Shipton, lead author of the study from The Australian National University (ANU).

“I don’t get the sense they were explorers looking over the horizon,” he said. “They didn’t have that same sense of wonder that we have.”

Shipton says this was clear from the way that the species created their tools and gathered resources.

“To make their stone tools they would use whatever rocks they could find lying around their camp, which were mostly of comparatively low quality to what later stone tool makers used,” he said. “At the site we looked at there was a big rocky outcrop of quality stone just a short distance away up a small hill.

“But rather than walk up the hill they would just use whatever bits had rolled down and were lying at the bottom,” he added. “When we looked at the rocky outcrop there were no signs of any activity, no artefacts and no quarrying of the stone.”

“They knew it was there, but because they had enough adequate resources they seem to have thought, ‘why bother?'”.

Conversely, other stone tool makers in later time periods, including Neanderthals and early Homo sapiens, climbed mountains to find the best quality stones and carried them over long distances.

The findings were published in PLOS One.