New Delhi: Amphibians are the most threatened vertebrate class, a new study that assessed the extinction risk of 8,011 amphibian species using the International Union for Conservation of Nature (IUCN) Red List of Threatened Species criteria has found.
The IUCN Red List is a critical indicator of the health of Earth’s biodiversity.
According to the peer-reviewed study published in the journal Nature last week, 40.7 percent of amphibians (vertebrates that inhabit both aquatic and terrestrial habitats) are facing extinction due to factors including climate change effects, habitat loss, etc.
Among authors of the study are researchers from around the world including from India, the US, China, Brazil, the UK, Indonesia, Haiti, Sri Lanka, Russia, Belgium, Japan, Spain, Turkey and Australia.
The study further reveals a significant shift in the foremost factor driving the amphibian extinction since 2004 — the first time a global assessment was conducted.
In 2004, disease, over-exploitation, and habitat loss were the main threats to amphibians.
But according to the study, climate change effects emerged as the ‘most common primary driver of status deteriorations’ in the nearly two decades since, and now affect 39 percent of amphibian species, compared to merely 1 percent in the period between 1980 and 2004.
“This is of particular concern because it often exacerbates other threats, such as land-use change, fire or disease,” write authors of the study. The findings, therefore, lay greater emphasis on the importance of exploring and enacting conservation measures that specifically tackle the impacts of climate change on amphibian species. Read more.
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JuMBOs: Planet-like objects
NASA’s James Webb Space Telescope has discovered new types of celestial objects in the Orion Nebula that had never been spotted before.
The 48 planet-like objects are similar to Jupiter in mass, but are not stars or planets.
They are called special kinds of planetary-mass objects (PMOs) since they have been found floating freely in pairs, bound by gravity. A paper in its preprint stage, submitted to the journal Nature for peer-review, discusses these findings.
Nebulas are regions in space where gas and dust come together sometimes under the pressure of gravity to form stars. They’re also called star nurseries.
The Orion Nebula is well-known and it’s the closest to Earth where massive stars were formed relatively recently. Scientists estimate the earliest stars in Orion were formed 300,000 years ago, which is very young in astronomical terms.
Astronomers Samuel Pearson and Mark J. McCaughrean studied the short-wavelength image of the Orion Nebula, and spotted the Trapezium cluster within. The Trapezium cluster is a huge cluster of stars discovered by Galileo Galilei. The astronomers also found certain objects drifting independently through space in gravitationally-bound pairs.
The study calls these pairs of PMOs Jupiter-mass binary objects or JuMBOs. They are very rare and surprising, because they are too small to ignite nuclear fusion like stars, and they do not orbit stars like planets. What’s more important is that they can help astronomers understand the origins of planets and stars in our solar system.
While other PMOs have been discovered before, as outlined by the research paper, the binary objects are “highly unexpected”, especially ones that are so close to the mass of Jupiter. Read more
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3-D printing brain tissues
In a remarkable breakthrough, researchers have engineered simplified versions of brain tissues by 3-D printing. These tissues resemble the human cerebral cortex, the part of the brain that handles complex thinking and neural connections.
The researchers used a novel droplet printing technology to make these tissues, which could have numerous applications in neuroscience and medicine.
The peer-reviewed study published in the journal Nature by scientists from the University of Oxford last week, added that this also opens up exciting possibilities for understanding brain development, testing drugs, and even personalised implantation treatments.
The cerebral cortex is the part of the brain responsible for higher cognition and intricate neural circuits. However, replicating its intricate structure in the lab has proven extremely challenging. Traditional tissue engineering methods have fallen short in creating such complex neural networks.
In this case, researchers used human-induced pluripotent stem cells, which can turn into any type of cell in the body. They then converted these cells into different kinds of neurons that are found in the layers of the cerebral cortex. Then, they used a special printer to arrange these neurons into a two-layered tissue, similar to the real cortex.
What’s fascinating is that the printed tissues showed the right signs, like specific biological markers, and formed a network of connections just like real brain cells do. They also integrated well with the mouse brain tissue when implanted.
This achievement marks a significant step forward in tissue engineering and neuroscience, offering new avenues for understanding and potentially treating brain-related disorders. Read more
‘Well-watered corridor for hunter-gatherers’
A new study has found evidence of an important route for early humans as they out-migrated from the African continent.
This was the conclusion of a research paper by scientists from University of Southampton (UK) and Shantou University (China), along with scientists in Jordan and Australia who conducted fieldwork in the Jordan Rift Valley, where they found ancient hand tools called ‘flakes’, which they dated to about 84,000 years ago using luminescence dating.
The study sheds light on the debate about how early humans left Africa and spread to other continents. In their paper, researchers have proposed two main routes that early humans may have used for this out-migration: the southern route and the northern route.
The southern route involved crossing the Bab-el-Mandeb strait into the southern regions of Arabia, possibly during glacial periods when sea levels were lower.
The northern route, on the other hand, involved passing through the Sinai Peninsula, the southern Levant, and then Arabia. This route was thought to be more likely during a period in history called the Marine Isotope Stage 5, which lasted between 129,000 to 71,000 years ago and was defined by high global mean temperatures.
The study published in the journal Science Advances last week shows that the northern route had a “well-watered corridor” that made it easier for hunter-gatherers to travel through what is now a desert area in the Levant. The route directed hunter-gatherers through Jordan into western Asia and northern Arabia.
This finding is consistent with previous evidence for the northern route, including human footprints and stone tools found in the Nefud Desert in Saudi Arabia, which date back to approximately between 120,000 and 85,000 years ago. Read more.
(Edited by Richa Mishra)
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