Tag: Environmental Science

Fire-Ravaged Kangaroo Island?

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“The bushfire crisis on Kangaroo Island is heart-breaking,” Professor Higgins-Desbiolles says, “and for a holiday destination that relies on tourism, the summer-holiday fires could not have come at a worse time.

Credit: Gary Jenkins
Fire on Kangaroo Island
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Kangaroo Island is one of South Australia’s most iconic tourism destinations, but as fires continue to rage across the once pristine environment, many holidaymakers are questioning whether to keep or cancel their travel plans.

While tourism authorities are calling for people to continue to visit Kangaroo Island, sustainable tourism expert, UniSA’s Dr Freya Higgins-Desbiolles says the situation is far more complex than boosting tourist numbers.

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“The bushfire crisis on Kangaroo Island is heart-breaking,” Professor Higgins-Desbiolles says, “and for a holiday destination that relies on tourism, the summer-holiday fires could not have come at a worse time.

“Kangaroo Island is a tourism dependent economy, and while tourism operators and authorities are calling for people to keep visiting Kangaroo Island, the fires are not yet out, CFS volunteers and defence personal are still being deployed, and infrastructure like the water treatment facilities are damaged.

“Additionally, critical services like the Kangaroo Island ferry are needed to transport emergency service personnel and equipment. I just think it’s too soon at this moment.”

Dr Higgins-Desbiolles says while it’s strategically important to plan the recovery of Kangaroo Island’s tourism businesses and primary producers, immediate tourist visits may not be the answer.

“While it is still be possible to visit Kangaroo Island at this time, it may not be the most viable or ethical decision under the current circumstances,” Dr Higgins-Desbiolles says.

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“For those of us who love Kangaroo Island and want to see its economy recover and thrive, the advice for the short term is provide donations if you can, buy Kangaroo Island produce and products, and when the time is right, book your holidays there and plan to consciously direct your spending to support the local economy.

“This is an incredibly emotional and confronting time for the 4500-plus residents of Kangaroo Island who are still reeling from the devastation and loss form the fires. They’re only just beginning a long road to recovery.

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“For those with later bookings on KI, please don’t cancel those just yet. If the local authorities give the greenlight, your holiday bookings may be just what helps Islanders get back on their feet.

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 “The grassroots campaign – #gowithemptyeskies – perhaps says it best: ‘When these fires have stopped, and the towns impacted are safe and trying to regain some sense of ‘normal’….plan a road trip. Go with empty eskies, empty cars and low fuel…(and) buy from their shops…empty eskies make, more of a difference that you could ever imagine.”

“It’s a small step, but one to which we can all safely contribute beyond the devastation of the fires.”

Inbreeding, Small Populations, and Demographic Fluctuations Alone Could Have Led to Neanderthal Extinction

Credit: Petr Kratochvil (CC0)
Neanderthal man

Neanderthal extinction could have occurred without environmental pressure or competition with modern humans

Small populations, inbreeding, and random demographic fluctuations could have been enough to cause Neanderthal extinction, according to a study published November 27, 2019 in the open-access journal PLOS ONE by Krist Vaesen from Eindhoven University of Technology, the Netherlands, and colleagues.

Paleoanthropologists agree that Neanderthals disappeared around 40,000 years ago—about the same time that anatomically modern humans began migrating into the Near East and Europe. However, the role modern humans played in Neanderthal extinction is disputed. In this study, the authors used population modelling to explore whether Neanderthal populations could have vanished without external factors such as competition from modern humans.

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Using data from extant hunter-gatherer populations as parameters, the authors developed population models for simulated Neanderthal populations of various initial sizes (50, 100, 500, 1,000, or 5,000 individuals). They then simulated for their model populations the effects of inbreeding, Allee effects (where reduced population size negatively impacts individuals’ fitness), and annual random demographic fluctuations in births, deaths, and the sex ratio, to see if these factors could bring about an extinction event over a 10,000-year period.

The population models show that inbreeding alone was unlikely to have led to extinction (this only occurred in the smallest model population). However, reproduction-related Allee effects where 25 percent or fewer Neanderthal females gave birth within a given year (as is common in extant hunter-gatherers) could have caused extinction in populations of up to 1,000 individuals. In conjunction with demographic fluctuations, Allee effects plus inbreeding could have caused extinction across all population sizes modelled within the 10,000 years allotted.

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The population models are limited by their parameters, which are based on modern human hunter-gatherers and exclude the impact of the Allee effect on survival rates. It’s also possible that modern humans could have impacted Neanderthal populations in ways which reinforced inbreeding and Allee effects, but are not reflected in the models. 

However, by showing demographic issues alone could have led to Neanderthal extinction, the authors note these models may serve as a “null hypothesis” for future competing theories—including the impact of modern humans on Neanderthals. 

The authors add: “Did Neanderthals disappear because of us? No, this study suggests. The species’ demise might have been due merely to a stroke of bad, demographic luck.” 

Paleontologists discover complete Saurornitholestes langstoni specimen

Illustration by Jan Sovak

Discovery provides valuable insight into evolution of theropod dinosaurs around the world

A small, feathered theropod dinosaur, Saurornitholestes langstoni was long thought to be so closely related to Velociraptor mongoliensis that some researchers called it Velociraptor langstoni — until now.

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The discovery of a nearly complete dromaeosaurid Saurornitholestes langstoni specimen is providing critical information for the evolution of theropod dinosaurs, according to new research by a University of Alberta paleontologist.

The 76-million-year-old species was long thought to be so closely related to Velociraptor from Mongolia that some researchers even called it Velociraptor langstoni–until now.

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The landmark discovery was made by world-renowned paleontologists Philip Currie and Clive Coy from the University of Alberta and David Evans, James and Louise Temerty Endowed Chair of Vertebrate Palaeontology at the Royal Ontario Museum. The research illustrates how Saurornitholestes differs from Velociraptor. Importantly, the research also identifies a unique tooth evolved for preening feathers and provides new evidence that the dromaeosaurid lineage from North America that includes Saurornitholestes is distinct from an Asian lineage that includes the famous Velociraptor.

“Palaeontology in general is a gigantic puzzle where most of the pieces are missing. The discovery and description of this specimen represents the recovery of many pieces of the puzzle,” said Currie, professor in the Department of Biological Sciences and Canada Research Chair in Dinosaur Paleobiology. “This ranks in the top discoveries of my career. It is pretty amazing.”

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Another piece of the puzzle

Saurornitholestes is a small, feathered carnivorous dinosaur within the dromaeosaurid family (also known as “raptors”) that was previously known from fragmentary remains. Discovered by Coy in Dinosaur Provincial Park in 2014, the new skeleton is remarkably complete and exquisitely preserved, with all the bones (except for the tail) preserved in life position. The new research, which focuses on the skull, shows that the North American form has a shorter and deeper skull than the Velociraptor. At the front of the skull’s mouth, the researchers also discovered a flat tooth with long ridges, which was likely used for preening feathers. The same tooth has since been identified in Velociraptor and other dromaeosaurids.

“Because of their small size and delicate bones, small meat-eating dinosaur skeletons are exceptionally rare in the fossil record. The new skeleton is by far the most complete and best-preserved raptor skeleton ever found in North America. It’s a scientific goldmine,” said Evans.

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The study also establishes a distinction between dromaeosaurids in North America and Asia. “The new anatomical information we have clearly shows that the North American dromaeosaurids are a separate lineage from the Asian dromaeosaurids, although they do have a common ancestor,” said Currie. “This changes our understanding of intercontinental movements of these animals and ultimately will help us understand their evolution.”

Future research will investigate the remainder of the skeleton as well as additional analyses on the relationships between dromaeosaurids.

The paper, “Cranial Anatomy of New Specimens of Saurornitholestes langstoni (Dinosauria, Theropoda, Dromaeosauridae) from the Dinosaur Park Formation (Campanian) of Alberta,” was published in The Anatomical Record (doi: 10.1002/ar.24241).