ريتشارد دوكنز's Blog, page 581
January 21, 2016
Sea Slugs Stock Up On Toxic Chemicals From The Sponges They Eat
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Chromodoris magnifica. Eva McClure
Sea slugs, also called nudibranchs or butterflies of the ocean, ingest toxic chemicals from the sponges they eat and store away the single most noxious compound to use against their predators later on. By preventing certain cellular processes, latrunculin A is highly toxic to fish, fungus, and even some cancer cell lines. The findings are published in PLOS ONE this week.
201-Million-Year-Old “Dragon Thief” Dinosaur Represents Major Evolutionary Step
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An artist's rendering of Dracoraptor hanigani, named after Wales' national animal, the dragon, and its two discoverers. Bob Nicholls
One of the oldest ever Jurassic dinosaurs has been discovered after it fell out of a cliff at Lavernock Point in South Wales, back in 2014. Now described in the journal PLOS ONE, this 201-million-year-old dinosaur fills in a key moment in dinosaur evolution.
Cyanobacteria Toxin May Cause Dementia
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A blue-green algae outbreak in Lake Taihu, China, may contribute to neurodegeneration in people living nearby. Jixin YU/Shutterstock
A chemical produced by blue-green algae has been found to cause biological markers associated with Alzheimer's disease in vervet monkeys. The discovery strengthens a suspicion that the toxin β-N-methylamino-L-alanine (BMAA) is contributing to the dementia crisis. In better news, the same study added to evidence for the amino acid L-serine's protective potential.
The Semen Of Honeybees Has Antimicrobial Properties That Could Help Protect The Hive
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Very little is known about the immune system of bees, and how they fight infection. Photografiero/Shutterstock
Honey has been shown to have anti-microbial properties, but it turns out that this might not be the only fluid that bees produce with pathogen-killing abilities. It seems that the semen of honeybees contains antibodies that help defend the insects from a potentially deadly sexually transmitted disease, and that the males might be passing this protection on to the queens when they mate.
2015 Was The Hottest Year Since Records Began By An Enormous Margin
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The warming of the planet is occurring at an increasingly rapid rate. NASA
Climatologists have been predicting it for the last few months, but with all the data now analyzed, it’s official: 2015 was the hottest year since records began in 1850. The news comes after three of the world’s major organizations have concluded their independent analysis of their climate data and unanimously drew the same conclusion.
Classic Fairy Tales May Be Thousands Of Years Old, Research Shows
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Researchers may have finally come up with a concrete date for "once upon a time." glenda/Shutterstock
As kids, many of us receive our first introduction to popular culture through fairy tales, with classic stories like Little Red Riding Hood, Jack and the Beanstalk, and the Three Little Pigs all captivating us throughout our younger years.
January 20, 2016
Volcano Role in Dino Death Gets Mercury Boost
Sixty-five million years ago, a six-mile-wide asteroid crashed into what’s now Mexico. The impact upended Earth’s climate, driving up to three-quarters of all species extinct, including the dinosaurs. That’s been the accepted explanation for mass extinction—for the last few decades, anyway.
But while scientists still think the asteroid dealt dinos and their contemporaries a serious blow, some have started to wonder if there wasn’t another culprit. Around the same time, huge quantities of lava were bubbling out of present-day India, forming what scientists call a large igneous province.
“This is large and huge volumes of lava flow, erupted in very short time. Short time at our geological scale.” Eric Font, a geoscientist at the University of Lisbon in Portugal. “So imagine a small country like France or Portugal, covered by lavas. So a large igneous province is a huge eruption—huge amount of continental flood basalt and volcanic gases.”
The gases Font refers to include carbon dioxide, sulfuric acid and other toxic compounds, which could have caused a host of problems for plants and animals—like climate change, acid rain and ocean acidification. That’s why in recent years researchers have debated whether the eruptions, which created rock formations known as the Deccan Traps, may have also played a role in causing the mass extinction.
Now Font has found more compelling evidence that that the eruptions had an impact on life. He and his colleagues identified a spike in mercury, which is produced by volcanoes, in ancient ocean sediments from southern France that span the extinction event. The spike coincides with layers of corroded shells and other indicators of environmental changes, suggesting the Deccan eruptions may have been to blame. The results were published in the journal Geology. [Eric Font et al, Mercury anomaly, Deccan volcanism, and the end-Cretaceous mass extinction]
Font’s study also raises the possibility that some of the death and destruction may have been due to mercury poisoning, of both the land and the sea. “It’s extremely toxic and it has a long residence time in the atmosphere. So, it allows mercury to travel around the world easily. It can lead to global scale perturbation.”
However, Font says the question isn’t settled yet. “Now, where we stand is: what is the contribution of the Deccan, what is the contribution of the impact.” Whatever the answer turns out to be, one thing is certain: 65 million years ago was a tough time to be a dinosaur.
—Julia Rosen
(The above text is a transcript of this podcast)
Map For Reading Faces Identified In The Human Brain
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The neurons that recognize different facial features are spread out in a similar pattern to the physical distribution of these features on an actual face. Maridav/Shutterstock
The ability to recognize faces is an important social skill, enabling us to distinguish our friends from our enemies while at the same time facilitating non-verbal communication in the form of facial expressions. Yet while most of us simply take this ability for granted, the reality is it wouldn’t be possible at all without the appropriate neurological infrastructure.
Origin Of York’s Roman “Gladiators” Traced
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The skull of one of the bodies found in York, thought to have possibly been a Roman gladiator. York Archaeological Trust
In what was then a far northern outpost of the Roman Empire, young men in England were fighting to the death for the entertainment of others. Just before, or after, their death the young men’s heads were cut off and the bodies buried on the outskirts of what would become the city of York.
Why Is Chocolate So Bad For Dogs?
Photo credit:
Ksenia Raykova/Shutterstock
It’s every dog owner's nightmare: entering the room to find a floor covered in candy wrappers and a overheated, panting dog with an explosive stomach.
But, while it’s fairly common knowledge that dogs and chocolate don’t mix, you probably don’t know much about the reason behind it. The American Chemical Society’s YouTube channel Reactions has recently released a video all about the science of dogs and their biological discord with chocolate.
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