Warming seas threaten to turn coral reefs from kaleidoscopes of color into bleached fields of rubble. To stop this degradation, some scientists are exploring a surprising salve: probiotics.
Dosing corals with a mix of beneficial bacteria staved off death in a heat wave simulated in an aquarium, researchers report August 13 in Science Advances. In comparison, nearly half of corals given a benign saline solution instead did not survive those same conditions. The research offers a proof of concept that probiotics could help some corals survive heat stress.
“The results are incredibly promising,” says Blake Ushijima, a microbiologist at the University of North Carolina Wilmington who wasn’t involved in the research. The work lends legitimacy to using probiotics as coral medicine, he says, “but we’re just scratching the surface. We don’t understand how a lot of these beneficial microbes work.”
Corals are not singular entities, but coalitions of cooperative players. Center stage are the photosynthetic algae that harness the power of the sun, providing energy to their animal host, the coral polyp. Scores of bacteria live in the coral too, many supporting their host by cycling nutrients or fighting pathogens. Collectively referred to as the coral “holobiont,” corals and their microbial partners form the bedrock of one of the most biodiverse ecosystems on the planet.
Source: Science News
Prehistoric cave paintings in Spain show early Neanderthals were artists
Neanderthals may have been closer to our species of prehistoric modern human than previously believed after cave paintings found in Spain proved they had a fondness for creating art, one of the authors of a new scientific report said on Sunday.
Red ochre pigment discovered on stalagmites in the Caves of Ardales, near Malaga in southern Spain, were created by Neanderthals about 65,000 years ago, making them possibly the first artists on earth, according to the study published in the Proceedings of the National Academy of Sciences (PNAS) journal.
Modern humans were not inhabiting the world at the time cave images were made.
The new findings add to increasing evidence that Neanderthals, whose lineage became extinct about 40,000 years ago, were not the unsophisticated relatives of Homo sapiens they been long been portrayed as.
Pigments were made in the caves at different times up to 15,000 and 20,000 years apart, the study found, and dispel an earlier suggestion that they were the result of a natural oxide flow rather than being man-made.
Joao Zilhao, one of the authors of the PNAS study, said dating techniques showed that ochre had been spat by Neanderthals onto the stalagmites, possibly as part of a ritual.
“The importance is that it changes our attitude towards Neanderthals. They were closer to humans. Recent research has shown they liked objects, they mated with humans and now we can show that they painted caves like us,” he said.Wall paintings made by prehistoric modern humans, such as those found in the Chauvet-Pont d’Arc cave of France, are more than 30,000 years old.
Source: India Today
Time To Visit The Neighbour
On 14 September 2020, a new planet was added to the list of potentially habitable worlds in the Solar System: Venus. Phosphine, a toxic gas made up of one phosphorus and three hydrogen atoms, commonly produced by organic life forms but otherwise difficult to make on rocky planets, was discovered in the middle layer of the Venus atmosphere. This raises the tantalising possibility that something is alive on our planetary neighbour. With this discovery, Venus joins the exalted ranks of Mars and the icy moons Enceladus and Europa among planetary bodies where life may once have existed, or perhaps might even still do so today.
I’m a planetary scientist and something of a Venus evangelical. This discovery is one of the most exciting made about Venus in a very long time – and opens up a new set of possibilities for further exploration in search of life in the Solar System.
First, it’s critical to point out that this detection does not mean that astronomers have found alien life in the clouds of Venus. Far from it, in fact.
Although the discovery team identified phosphine at Venus with two different telescopes, helping to confirm the initial detection, phosphine gas can result from several processes that are unrelated to life, such as lightning, meteor impacts or even volcanic activity.
However, the quantity of phosphine detected in the Venusian clouds seems to be far greater than those processes are capable of generating, allowing the team to rule out numerous inorganic possibilities. But our understanding of the chemistry of Venus’ atmosphere is sorely lacking – only a handful of missions have plunged through the inhospitable, carbon dioxide-dominated atmosphere to take samples among the global layer of sulfuric acid clouds.
So we planetary scientists are faced with two possibilities – either there is some sort of life in the Venus clouds, generating phosphine, or there is unexplained and unexpected chemistry taking place there. How do we find out which it is?
First and foremost, we need more information about the abundance of phosphine in the Venus atmosphere, and we can learn something about this from Earth. Just as the discovery team did, existing telescopes capable of detecting phosphine around Venus can be used for followup observations, to both definitively confirm the initial finding and figure out if the amount of phosphine in the atmosphere changes with time. In parallel, there is now a huge opportunity to carry out lab work to better understand the types of chemical reactions that might be possible on Venus – for which we have very limited information at present.
Once more unto the breach
But measurements on and from Earth can take us only so far. To really get to the heart of this mystery, we need to go back to Venus. Spacecraft equipped with spectrometers that can detect phosphine from orbit could be dispatched to the second planet with the express purpose of characterising where, and how much, of this gas is there. Because spacecraft can survive for many years in Venus’ orbit, we could obtain continuous observations with a dedicated orbiter over a much longer period than with telescopes on Earth.
But even orbital data can’t tell us the whole story. To fully get a handle on what’s happening at Venus, we must actually get into the atmosphere.
And that’s where aerial platforms come in. Capable of operating above much of the acidic cloud layer – where the temperature and pressure are almost Earth-like – for potentially months at a time, balloons or flying wings could take detailed atmospheric composition measurements there. These craft could even carry the kinds of instruments being developed to look for life on Europa. At that point, humanity might finally be able to definitively tell if we share our Solar System with Venusian life.
A new dawn for Venus exploration?
Thirty-one years have elapsed since the United States last sent a dedicated mission to Venus. That could soon change as Nasa considers two of four missions in the late 2020s targeting Venus. One, called Veritas, would carry a powerful radar to peer through the thick clouds and return unprecedented high-resolution images of the surface. The other, DaVinci+, would plunge through the atmosphere, sampling the air as it descended, perhaps even able to sniff any phosphine present. Nasa plans to pick at least one mission in April 2021.
I have argued before for a return to Venus and will continue to do so. Even without this latest scientific discovery, Venus is a compelling exploration target, with tantalising evidence that the planet once had oceans and perhaps even suffered a hellish fate at the hands of its own volcanic eruptions.
But with the detection of a potential biomarker in Venus’ atmosphere, we now have yet another major reason to return to the world that ancient Greek astronomers called phosphorus — a name for Venus that, it turns out, is wonderfully prescient.
The writer is associate professor of planetary science, North Carolina State University, US. This article first appeared on www.theconversation.com
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