Category: NWT_Animals

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Archaeology NWT_Animals SCI

Baby snake from dinosaur age found frozen in amber

For the first time ever, scientists discovered an ancient snake embryo contained in 105-million-year-old amber. The discovery reveals important information on the evolution of modern snakes.

“This snake is linked to ancient snakes from Argentina, Africa, India and Australia,” said paleontologist Michael Caldwell, lead author of the study and professor in the Department of Biological Sciences. “It is an important—and until now, missing—component of understanding snake evolution from southern continents, that is Gondwana, in the mid-Mesozoic.”

Caldwell and his team, which includes researchers from China, Australia, and the United States, tracked the migration of the ancient Gondwanan snakes all the way back to 180 million years ago when they were transported by tectonic movements created by continents and their parts.

The team also gained information from the amber fragment that encased the specimen.

“It is clear that this little snake was living in a forested environment with numerous insects and plants, as these are preserved in the clast,” Caldwell said. “Not only do we have the first baby snake, we also have the first definitive evidence of a fossil snake living in a forest.”

The team used computerized tomography (CT) scans to study the ancient snake and compare it with the children of modern snakes, shedding light on the embryology and development of the ancient specimen.

“All of these data refine our understanding of early snake evolution, as 100-million year-old snakes are known from only 20 or so relatively complete fossil snake species,” Caldwell said. “There is a great deal of new information preserved in this new fossilized baby snake.”

The findings were published in Science Advances.

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NWT_Animals Research SCI

New model identifies main factors that shaped evolution

A new computer simulation takes into account the numerous factors that drive evolutionary extinction and adaptation. The study outlining the model attempts to bring us closer to understanding the complex interactions between climate change and topography, and how these interactions affect the biodiversity and evolutionary histories of species in their natural ecosystems.

“We had hoped to be able to model in the simulation the most fundamental processes that shape the geography of life on Earth,” said Robert Colwell, who led the research with Brazilian colleague Thiago F. Rangel in collaboration with Neil Edwards and Philip Holden in the United Kingdom.

To create their model, the team looked to South America, which is the most biologically diverse continent on the planet. And since the Andes mountain range started developing 25 million years ago, it created an extremely varied landscape that gave rise to a plethora of biodiversity, making it a perfect area to study the evolution and ecology of biodiversity.

“The Andes are the longest mountain range on Earth, and the only trans-tropical one,” Rangel said. “They sit right beside the Amazon, the planet’s largest tropical rainforest and river basin. This is the reason South America has such exuberant biodiversity.”

“Our results demonstrate how intimately the evolution of life depends on the changing physical environment,” said Neil Edwards of The Open University modelling team.

The model comes at a time of unprecedented climate change, highlighting the unique and dynamic power of climate change and the many ways it shapes the evolution of life on Earth.

“The current pace of human driven climate change is much, much faster than anything in our model, but the same processes are happening in terms of species’ range shifts today,” Colwell said.

The findings were published in Science.

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Archaeology NWT_Animals SCI

Scientists suggest that winged reptiles existed before dinosaurs

Researchers just discovered a new species of pterosaur, which is the family of prehistoric flying reptiles that includes the pterodactyl. Interestingly, the specimen is approximately 210 million years old, which pre-dates its relatives by 65 million years.

The bones of the new species, named Caelestiventus hanseni, were preserved in desert oasis remains. They suggest that the species thrived on Earth prior to the evolution of dinosaurs.

The pterosaurs are the oldest flying vertebrates and a close relative of Dimorphodon. And since they were the first to evolve powered flight, their bird-like skeletons are often delicate and in a crushed state.

“Most of them are heavily distorted; literally like roadkill,” said lead author Brooks Britt, from Brigham Young University in Utah.

“The bones are so delicate, you can’t take them all the way out of the rock because they would just fall apart,” he added.

The team created a digital profile of the skull using a computed tomography (CT) scan and then printed a 3D model, which revealed a complex set of teeth.

“This one site we’ve pulled out 18,000 bones from an area the size of a good sized living room,” Britt said. “And there’s only one pterosaur.”

Although the specimen hadn’t reached adulthood, it had a wingspan of one-and-a-half meters.

“It was probably the biggest of its day,’ Britt said. “Among its peers, we have no evidence that any rival came close to that.”

The team plans to continue conducting research on the fossil in order to better understand what it ate and how it lived.

The findings were published in Nature Ecology & Evolution.

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Archaeology NWT_Animals SCI

British workers discover 140-million-year-old dinosaur footprints

British workers at Purbeck quarry in Swanage along the Jurassic Coast just discovered a set of 140-million-year-old dinosaur footprints that are believed to originate from a herd of massive sauropods that roamed the landscape years ago.

Sauropods are the first successful herbivorous dinosaurs and lived as long as 120 years. Researchers believe they likely resided along Britain’s south coast from the late Triassic through to the late Cretaceous periods

Interestingly, the site was the location of a similar discovery of 52 dinosaur prints back in 1997.

“The footprints are like giant saucer-shaped depressions which are up to three-foot in diameter but only half an inch deep,” said Matthew Bennett from Bournemouth University, who guided the extraction. “They belonged to the Sauropods which were very large dinosaurs the size of double-decker buses and very gregarious, travelling in groups.”

The team used special equipment called DigTrace to create three-dimensional documentation of the tracks.

“This technology is now being used by the police to help track criminals via their footprints, but we can also use it to record and preserve rare footprints like these,” Bennett said.

“The beauty of capturing the tracks in 3D is that they can be analysed digitally and even printed in the future, with no need to hold up the quarrying for long,” he added.

Bennett said now that the footprints have been extracted intact, the team will focus on readying them for a museum display.

“I’ve spent my life travelling the world to look for fossil footprints so it is nice to find some on our doorstep,’ he said.

The quarry was shut down for 10 days to make way for the excavation.

“It became apparent that we had come across something of historical interest, so working closely with the National Trust and Professor Matthew Bennett of Bournemouth University, we were able to move forward in the best way without stopping progress in the quarry itself,” said David Moodie from Lewis Quarries.”

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NWT_Animals Research SCI

Bacteria go extinct at higher rates than we thought, study says

A new study suggests that bacteria go extinct at fairly high rates, which contradicts the common scientific view that microbe taxa rarely die off due to their large population sizes.

The team behind the study used large-scale DNA sequencing and analysis to produce the first-ever evolutionary tree that covers a large chunk of the bacteria present on the Earth over the last billion years.

“Bacteria rarely fossilize, so we know very little about how the microbial landscape has evolved over time,” said Stilianos Louca, a researcher with University of British Columbia’s Biodiversity Research Centre. “Sequencing and math helped us fill in the bacterial family tree, map how they’ve diversified over time, and uncover their extinctions.”

Louca and his team believe that between 1.4 and 1.9 million lineages of bacteria are present on Earth, and claim that there have been 45,000 to 95,000 extinctions in the last million years alone.

“While modern bacterial diversity is undoubtedly high, it’s only a tiny snapshot of the diversity that evolution has generated over Earth’s history,” he said.

“This study wouldn’t have been possible 10 years ago,” said Michael Doebeli of UBC and senior author on the paper. “Today’s availability of massive sequencing data and powerful computational resources allowed us to perform the complex mathematical analysis.”

The team hopes to next focus on how to determine the evolution of the physiological properties of bacteria over time. Not only that, they want to see if their ecological diversity increases in a similar manner as their taxonomic diversity. Should this be true, even simple ancient bacteria could still have the potential to develop new methods of survival.

The findings were published in Nature Ecology & Evolution.

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NWT_Animals Research SCI

Homo sapiens created ecological niche to break away from other hominins

A new review of palaeoenvironmental and archaeological data from the hominin dispersals in the Middle and Late Pleistocene suggests that Homo sapiens underwent unique adaptations and environments compared to previous hominins, which could be the reason that we are the last surviving hominin on the planet.

The study suggests that humans have been able to occupy such diverse environmental settings due to what is referred to as a new ecological niche called the “generalist specialist.”

“A traditional ecological dichotomy exists between ‘generalists’, who can make use of a variety of different resources and inhabit a variety of environmental conditions, and ‘specialists’, who have a limited diet and narrow environmental tolerance,” said Patrick Roberts, lead author of the paper.

“However, Homo sapiens furnish evidence for ‘specialist’ populations, such as mountain rainforest foragers or palaeoarctic mammoth hunters, existing within what is traditionally defined as a ‘generalist’ species,'” he added.

Not only that, but there is an increasing amount of evidence for hominin interbreeding, which the team suggests is a sign that researchers should begin to focus on the connection between fossils and their environment.

“While we often get excited by the discovery of new fossils or genomes, perhaps we need to think about the behavioural implications of these discoveries in more detail, and pay more attention to what these new finds tell us about new the passing of ecological thresholds,” said Brian Stewart, co-author of the study.

“As with other definitions of human origins, problems of preservation also make it difficult to pinpoint the origins of humans as an ecological pioneer,” Roberts concluded. “However, an ecological perspective on the origins and nature of our species potentially illuminates the unique path of Homo sapiens as it rapidly came to dominate the Earth’s diverse continents and environments.”

The findings were published in Nature Human Behavior.

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NWT_Animals Research SCI

Study examines link between pollution and wildelife behavior

Scientists from the University of Portsmouth have created novel scientific tests that could help us better understand the connection between wildlife behavior and pollution. This unique field of behavioral toxicology has become a focus in environmental sciences, with many new studies suggesting that exposure to chemicals can change animal behavior.

The team examined tiny shrimp-like crustaceans called amphipods and found that shape and tank size can affect the time they spend next to a wall, exploratory behaviors, and swimming speed.

“These results are really important for us and the scientific community in determining the correct experimental design,” said Alex Ford, senior author on the study. “If scientists don’t give the organisms the space to behave they might not detect the impacts of chemical pollution.”

“Environmental toxicologists around the world often use similar processes but not always for the same species for their pollution testing,” he added. “This could lead to two groups of scientists getting very different results if their study organism are not the same species.”

“For example, a chemical might have the capacity to alter a certain behaviour but if two closely related species have subtly different reactions to a stimulus (light for example) then this might mask the impacts of the pollutant.”

Matt Parker, co-author of the paper, believes that while least sentient organisms are typically examined due to scientific ethics, they can provide lots of valuable information that can lead to significant advancements in the field.

“This set of studies has highlighted behavioural diversity in two closely related invertebrate species, suggesting that these organisms may be useful for studying the basis of more complex behaviours, and the potential to study the effects of different drugs on behavioural responses,” he said.

The findings were published in PeerJ.

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HND_Disease NWT_Animals Research SCI

Scientists to genetically engineer mice to stop Lyme disease

Scientists want to take the radical evolutionary step of genetically engineering white-footed mice of Nantucket and Martha’s Vineyard to rid the islands of Lyme disease. The vile bacterial infection causes fatigue, fevers and rashes.

According to the Centers for Disease Control and prevention, Lyme disease can spread to the joints, nervous system and heart if left undetected. The people living on these bucolic summer retreats are eager to eradicate the scourge given the fact that as many as 40 percent of the population on just Nantucket have Lyme disease.“Here in the Northeast, our natural disaster is Lyme disease,” said Kevin Esvelt, who specializes in evolutionary and ecological engineering at MIT Media Lab.

Almost everyone associates deer with this illness, but transmission starts when an adolescent tick bites a white-footed mouse carrying the Lyme bacteria. If they can eliminate the bacteria from mice then it might solve the problem.

Esvelt’s goal is to do that by tinkering with their genetic code. He and his team want to heritably immunize the local white-footed mice.

Some mice develop immunity to Lyme naturally. However, they do not pass along that immunity to offspring without some assistance from science.

That is where Harvard immunologist Duane Wesemann enters the picture. Once he isolates the genetic code for Lyme immunity, he will be able to edit it into the genome of many more mice.

 

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NWT_Animals NWT_Environment SCI

Moth slumber parties are held in hollow trees, study says

Although moths are typically loners, scientist Andrei Sourakov found a unique population of the glassy black Idia species inside of a hollow tree. Afterwards, he found 100 of the same species congregated in another hollow tree, and their numbers eventually reached 400.

“That’s incredible,” he said as he filmed it. “So many moths!”

Each time, the moths oriented themselves at the top of the tree and out of light, keeping slightly away from each other. But they weren’t mating and larvae weren’t feeding nearby, suggesting that they were resting and waiting for night.

“This is completely new,” Sourakov said. “Nobody has recorded daily communal roosting behavior in moths. This appears to be a unique behavior in this species and an important part of its biology.”

Although he’s not exactly sure why the moths are grouping together, Sourakov believes it might be a “safety in numbers” strategy for defense.

“Large numbers of prey in a confined space presents a challenging environment for predators,” he said. “Spiders, for instance, would have to constantly repair their webs torn by these many moths. But most importantly, the percentage of lost prey is not significant enough to undermine the population. ‘Safety in numbers’ doesn’t mean everyone is safe, but the population is safe.”

Sourakov believes that the moths signal and plan to assemble using sex hormones.

“There are so many unknowns in nature,” he said. “Even the exact identity of this moth species is unclear and is waiting to be described. You don’t have to venture into exotic places to make discoveries. Just look in your backyard. Some moths are small, brown and might seem boring, but the impact that stories like this make on a perception of a place cannot be underestimated.”

The findings were published in the journal Tropical Lepidoptera Research.

Categories
Archaeology NWT_Animals SCI Science

Study uncovers mystery of ancient vegetarian cave bear diet

One of the two bears species that roamed Europe during the Late Pleistocene period was the extinct and mostly vegetarian Ursus spelaeus cave bear. And now, a new study sheds light on the evolution of cave bear diets and the vegetarian species’ unique morphology.

The study suggests that the the Deninger’s bear (Ursus deningeri), which is the direct ancestor of the vegetarian cave bear, had unique morphology in is mandible, teeth, and cranium, which is likely due to its consumption of vegetables.

“There is an ongoing discussion on the extent to which the classic cave bear was a vegetarian,” said Mikel Arlegi, doctoral candidate at the Universities of the Basque Country and Bordeaux and co-author of the study. “And, this is especially why the new information on the diet of its direct ancestor is so important, because it teaches us that a differentiation between the diet of cave bears and brown bears was already established by 500 thousand years ago and likely earlier.”

“The analyses showed that Deninger’s bear had very similarly shaped mandibles and skull to the classic cave bear”, said Anneke van Heteren, lead-author of the study and Head of the Mammalogy section at the Bavarian State Collection of Zoology. The findings imply that they were adapted to identical food types and were mostly vegetarian.

The team also found shape variations between the Deninger’s bears that lived on the Iberian Peninsula and those that lived in the rest of Europe, and have come up with numerous hypotheses to explain them.

“However, more fossils are necessary to test these three hypotheses,” said Asier Gómez-Olivencia, an Ikerbasque Researcher at the University of the Basque Country.

The findings were published in Historical Biology.