In this week’s Sunday Science: apes might have evolved upright far earlier than thought; a new drug against the most common cancer mutation; cooperative flesh-eating bacteria and a test for antibiotic resistance. Also: 3D Star Wars style displays, bad psychology, and a celebration of 150 years of publication of Nature magazine….
Upright walking in apes might have evolved millions of years earlier than thought: researchers have found fossils of a 12 million year old ape that lived in Bavaria, Europe, which showed clear evidence of adaptation to upright walking. The animal, named Danuvius guggenmosi, would have been a common ancestor to both the great apes and humans, and used “extended limb clambering” – using arms and legs equally – to clamber about the trees. Ancestral humans diverged from our ape cousins around 5 million years ago; it seems that walking upright may not be as uniquely human as we think it is. Original study published in Nature here (paywalled), with a good News & Views piece here (open access).
3D images have been created from just a speck of foam. Researchers in the field of volumetric displays have used tiny speakers to generate ultrasound waves which move the little foam bead around so fast it creates continuously generated 3D images, hovering in space. This week’s featured image shows a simple virtual butterfly created using the process. This seems to be a rapidly evolving technology; I reported a previous development in the field, which reproduced the famous Princess Leia 3D holographic image from Star Wars, in early 2018. Original highly technical physics paper here, for those who can understand it.
Necrotising fasciitis is one of those horrific diseases you really wouldn’t want to get (although fortunately it’s quite rare): the “flesh-eating” disease can kill up to half of the people it affects, and survivors often have to have limbs amputated. Contrary to the name, the bacteria are not “eating” the flesh, but rather the soft tissue of the body is being destroyed by it. It can be caused by more than one type of bacteria, often something like Streptococcus pyogenes, that generally lives harmlessly on the skin and then gets in through an infected wound: it’s never been quite clear why this can sometimes lead to such a deadly infection. Now it appears that sometimes two different types of bacteria can combine to cause the disease. The bacteria are actually the same species, Aeromonas hydrophila, but different strains: one produces a toxin that damages tissue, allowing the other strain to enter damaged flesh and spread in the bloodstream, in some cases systemically around the body. This species commonly causes necrotising fasciitis in wounds exposed to dirty water. Neither of the two strains were particularly deadly on their own, but together proved nearly lethal, leading to a quadruple amputation in the poor patient. By profiling the bacterial subtypes present in an infection like this, it should help in selecting the correct antibiotic combination to kill all the strains present. Original paper published in PNAS here.
More for bacteria now, with a new test able to detect antibiotic resistance in under 45 minutes. This could be a really useful aid to treating infections, ideally before they become very serious. Currently it takes at least 2 days to screen test patient samples, by which time it could be too late. Antibiotic resistance, in which bacteria have evolved an ability to overcome the drugs used to kill them, is a very serious problem that is getting worse all the time: millions of people die of resistant infections each year. Some infections, like multi-drug resistant tuberculosis, some strains of gonnorhea and the infamous MRSA (methicillin-resistant Staphylococcus aureus), are resistant to nearly all known treatments. By profiling an infection quickly, it means you won’t end up trying to treat a patient with an antibiotic that won’t work. Original paper published in Biosensors and Bioelectronics here.
One of the most frequent mutations driving cancer development (across the board) is a mutation in a key component of signalling pathways called Ras. This is a small protein that is activated by exchanging one type of nucleotide (GDP) for another (GTP), subsequently switching on pathways controlling cell growth and division. It has an instrinsic “off” mechanism, as it converts the GDP back to GTP by itself. Many cancers, however, have a mutated form, Kras, that remains stuck in the “on” position. Unfortunately, because it’s such a small protein, it’s been remarkably difficult to design a drug that will specifically target it; a few were developed in animal models but showed no success in human trials. Now a new candidate has been developed which blocks Kras binding GTP in the first place and that has been shown to shrink tumours in patients too – potentially a significant development. Original paper here.
The work of the famous and controversial psychologist Hans Eysenck was last month ruled “unsafe” after a review of his published papers by King’s College London. Specifically, they recommended that several of his published papers linking the risk of cancer and heart disease to personality be retracted. A brief gaze over his career reveals many controversies: linking race to IQ being the most notable of these, which was what I personally had previously been aware of, and is basically bunkum. (I do find that there’s sometimes a dangerous tendency for some experts to make links to conclusions not in their field: he may have been talented at psychology, for all I know, but reaching out into genetics was way outside his expertise). What about that “link” to cancer and heart disease? Eysenck claimed that personality played a bigger part in the development of cancer and heart disease than smoking. The effects he claimed were ludicrously large: people with a “cancer prone” personality are supposedly 121 times more likely to get cancer than those without (I don’t know if he ever came up with any explanation as to how this supposed effect happened). Frankly, I don’t know how this could ever have been taken seriously. I also wonder how much of it is responsible for the rather poisonous “positive thinking” attitude people suffering from cancer in particular have been advocated to adopt (in the face of the psychological stress of being dangerously ill). At any rate, you can listen to the whole sorry saga via the Guardian’s weekly science podcast here, which also has links to the relevant publications surrounding the controversy.
And finally, the premier science magazine Nature is celebrating 150 years of publication. There’s a nice overview of their major discoveries and changes in the journal to be found here, and an interesting graphical piece charting changing trends in publication here. (I am most amused at the rapid growth of the keyword “receptor” in biology). Within the journal, for those who are interested, you can also find a series of short comment pieces on major discoveries, including the structure of DNA, the first exoplanet, and nanomaterials. Finally, a delightful pretty video showing a network analysis of those 150 years of published papers below:
A virtual butterfly that can hover in space. Credit: Eimontas Jankauskis/University of Sussex via Nature Publishing.