New Delhi: A new study has revealed a fascinating aspect of prehistory — the interactions between Neanderthals and cave lions in the Middle Paleolithic era, which spanned from 250,000 to 30,000 years ago. The findings overturn previous beliefs about how early humans dealt with large predators.
The study, which was published in the journal Nature on 12 October, focussed on archaeological sites in Germany.
Eurasian cave lions were an ancient species of predators, thought to be bigger than modern lions. They are believed to have disappeared about 12,000 years ago.
The researchers from Germany found a 48,000-year-old cave lion skeleton in Siegsdorf, which had clear signs of being killed by early humans.
They analysed a punctured wound in one of the lion’s ribs and concluded that it was caused by a Neanderthal using a wooden spear, making it the oldest known case of a human killing a large predator.
The researchers also discovered lion bones at Einhornhöhle that dated back to an astonishing 190,000 years ago. These findings suggest that Neanderthals were using cave lion skin, showing their ingenuity and adaptability. Read more.
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How female frogs ‘play dead’ to dodge mating
Researchers in Germany in a new study have shed light on the sexual dynamics in frogs. They observed how males and females may employ differing reproductive strategies, and concluded that female frogs often ‘fake their own death’ to avoid unwanted mating.
The study published in Royal Society Open Science on 11 October focussed on the European common frog, Rana temporaria.
In some species of frogs, a pattern is seen where mating events expose females to higher risk. Many males try to get a female, and the latter seems unable to reject unwanted partners.
But this new research identifies three distinct female mate avoidance behaviours — ‘rotation,’ ‘release call(s),’ and tonic immobility, akin to feigning death.
Also, these strategies are linked to the size of the female, with smaller frogs demonstrating a greater ability to escape unwanted male advances.
Tonic immobility as a tactic to deter mating or fend off male harassment has been observed in only a handful of species, and this study reveals it in the context of European common frogs for the first time. Read more.
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How hot is too hot?
New research by scientists from Pennsylvania State University shows that humans are more vulnerable to heat stress than previously thought and tropical countries face higher risks from global warming.
A paper published in the Proceedings of the National Academy of Sciences on 9 October found that humans can tolerate less heat than previously assumed.
The conventional wisdom was that a “wet-bulb temperature (Tw) of 35 °C” was the maximum limit for the human body to cope with extreme heat. Wet-bulb temperature is a measure of the humidity in the air. This limit was often called the human adaptability or survivability limit.
However, the paper challenges this limit and claims that experiments show that even lower temperatures can affect our ability to control body heat with serious health consequences. The paper suggests that the new wet-bulb temperature should be 30.6 °C.
To estimate future risks, researchers used this revised limit with advanced climate models, the results of which are alarming.
The paper suggests that humans are more prone to dangerous moist heat stress than previously thought — especially if global warming goes beyond 2°C above pre-industrial levels.
At 3°C of warming, the risk increases sharply, especially in regions like the Middle East, the Indus River Valley, eastern China, sub-Saharan Africa, and the US Midwest, which could face intense heat stress.
These findings imply that future heat extremes will be worse than historical experiences, exceeding current coping strategies. Read more.
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Climate change threatens beer flavour
Water stress and climate change may affect the taste of hoppy beer— one of the most popular drinks in the world — a new study has found.
Hops — the flowers of the hop plant — are the key ingredient that gives beer its distinctive flavour. These fragrant cones add not only bitterness but also essential oils and polyphenols. The demand for high-quality hops has increased significantly due to the recent trends in craft beer, which focus more on aroma and flavour.
However, a new study by Czech scientists published in Nature on 10 October warns of the perils that climate change poses to hop production — especially in regions ideal for cultivating these essential beer ingredients
The scientists studied European hops from 1970 to 2050, using real-world weather data and climate projections. They found that as temperatures increase by 1.4°C and rainfall decreases by 24mm, hop production in important regions such as Germany, the Czech Republic, and Slovenia face unprecedented challenges.
By 2050, the researchers believe that hop yield is expected to fall by 4 to 18 percent and alpha content (which is responsible for the bitterness in beer) is expected to decrease by 20-31 percent.
These findings highlight the urgent need for adaptation measures to protect the booming global brewery sector from the looming threat of climate change. Read more.
(Edited by Richa Mishra)
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