Still mostly biology this month though the most visible bit of news is space stuff.
This being NASA’s announcement that its Mars Reconnaissance Orbiter (MRO) has discovered liquid water on the planet’s surface. The water involved is highly briny, which helps keep it liquid at low temperatures, and even so it only flows seasonally when it’s not too cold. Plus, of course, we’ve long known that water already exists on Mars in the form of ice and ancient water deep beneath the surface. Still it’s a significant milestone that will reinvigorate the search for life on the red planet. I suspect that this will also cause NASA to be much more careful about contaminating Mars with microbial life from Earth.
But the most significant finding over the past month is probably this paper about a new species of the homo genus found in Africa. Now dubbed homo naledi, they are represented by fossils found of at least 15 distinct individuals in South Africa. The discovery was originally made in 2013 but it has taken until now to fully study the fossils and the researchers’ conclusion is that the unique morphology of the specimens warrant classifying them as belonging to a hitherto unknown and now extinct specifies of humanity. Early reporting of this paper excitedly emphasized that they may had culture as the fossils were all found together is what is thought to be a burial site. This is a shock given that this should date from long before any form of civilization. But I’m dubious about this since it’s also possible that it was just a convenient place to dispose of trash.
Moving on to more sci-fi stuff, DARPA announced the development of neural technologies that allow patients to experience sensation from prosthetic limbs. This is rather crude at the moment as the connection is formed with electrode arrays on the patient’s and sensory motor cortex to torque sensors on an artificial hand, allowing the patient to both feel and control the individual fingers of the hand. Basically it amounts to a proof that cybernetic limbs that can transmit a sense of touch are possible.
Finally, this Naturearticle talks about how a genomics firm in China is now offering gene-edited pigs for sale to the public as pets. These pigs have been modified to disable one of two copies of the growth hormone receptor genes that they possess, so that instead of their normal weight of around 35 to 50 kilograms, they will grow only to about 15 kilograms. The company also claims that in the near future, they will offer versions that can be modified to have different coat colors and patterns. But as the article notes, pigs’ size are not the only reason why they are not generally raised as household pets and owners who expect to be able to house train them will end up being disappointed.
Okay, no more space articles this month. Instead, it’s time for biology.
This Molecular Psychiatrypaper describes an attempt to identify genes that are associated with high intelligence. Specifically they sampled genes from individuals with IQs of over 170 and matched them against a control group to search for genes that are common in the high intelligence group but rare in the control group. Their finding however is consistent with previous such studies in that no genes that are reproducibly associated with high intelligence can be identified even though individual differences in intelligence is known to be highly heritable. This suggests that inherited intelligence relies on the complex interplay of many different genes rather than the presence of any rare ones.
As no doubt everyone reading this blog will know, the past month has seen an absolute bonanza of space-related science news. Lots of cool and exciting stuff there but we’ll start with the non-space stuff first.
Given my recent post on the Dog Emotion and Cognition course, this first bit is especially relevant. This BBC article covers a Japanese experiment which shows that dogs are able to observe strangers interacting with their owners and calibrate their own behavior accordingly. Specifically when offered food by a stranger, dogs will decline the offer if the stranger has previously been observed as acting in a “mean” manner to its owner.
It’s been a particularly rich month for science with some really cool articles. Here goes:
Due to my own interest in computer science, I couldn’t not include this. This Popular Mechanicsarticle explains how a computer program created a model of the inner workings of a flatworm. The scientists were interested in how the worm’s genes regulate the organism’s impressive regenerative ability. The program essentially took a brute force approach to the problem, randomly making guesses and matching the results to the available data and refining its guesses until it ended up with a model that is a perfect match. This is the kind of work that would take human researches ages to do manually even if humans can explore the search space more intelligently and it’s likely that we’re going to see more and more of this kind of science.
It’s been said again and again that science is a work in progress and we’re constantly revising what we know. But one of the areas that everyone has long thought is settled science are the structures of the human body. It turns out we were wrong when we thought we’d thoroughly mapped every part of the body because scientists have discovered a lymphatic network that links the brain and the immune system as this Neuroscience Newsarticle explains. Needless to say this is a huge bit of news that has implications for every brain disease in existence and all of the medical textbooks will need to be revised.
Staying on the subject of the brain, this article from Hacked talks about how a team has managed to build what is in effect an artificial neuron. They claim that it is made of organic bioelectronics with no living parts but is capable of mimicking the function of a normal organic neuron in every way. Since the device is currently the size of a fingertip, it’s not going to be implantable into a real brain any time soon but you can bet that miniaturization is on the cards.
Finally here is yet another paper on the favorite thought experiment of quantum physicists, Schrödinger’s cat. This article from Nature covers a new, purely theoretical finding that quantum superpositions would collapse in the presence of gravity. As such the classical setup of the cat would only work in deep, interstellar space far from any planet.
Five articles this month, with an emphasis on the softer sciences.
For a light start, this first one is a profile in The New York Times about a scientist who has spent his career on researching the topic of communication between animals of different species. The canonical example here is that when birds make noise, other animals in the forest are able to hear it and respond appropriately. One particularly cool example is how a squirrel is able to understand bird alarms about a predatory raptor in the air and make noises of its own that are acoustically similar to the original bird alarms.
Not quite the end of the month yet, but let’s get this out of the way:
The biggest bit of news naturally is that Chinese scientists have used the CRISPR/Cas9 technique that I talked about last month to experiment on human embryos. The news first appeared in Nature, but not as a paper since it was rejected. The team used non-viable embryos that could never have fully developed to stave off ethical concerns and the attempt to modify the gene responsible for β-thalassaemia is considered to be a failure because only a small proportion of the sample accepted the modifications and there a large number of unintended mutations. Nevertheless the wider implication is that germ-line gene editing on human samples is now no longer a secret.
The next two articles deal with Internet culture and online behavior. The first one talks about an algorithm that can be used to identify online trolls which might be used to help police online spaces like social networks and forums.
The second one talks about the toxicity of the comments in many online articles and posts. In particular, it discusses findings about how even reading prejudiced comments can cause other people to post more prejudiced comments themselves, leading to a downward spiral of poor quality comments.
Continuing on in the sphere of the social sciences, this paper discusses how organizations that explicitly frame themselves as being meritocratic actually end up favoring men instead over women. This matters because I’ve often had occasion to debate people who oppose feminism on the grounds that they favor egalitarianism instead of measures that actively promote the interests of women over men.
Finally, on a more lighthearted note, here’s an article from The Economist about a robot chef that soon become a commercial reality. The idea is to have it replicate precisely the movements of celebrity chefs. However the technology isn’t quite there yet since the robot isn’t even trusted with a knife at the moment and a human still needs to prepare all of the ingredients and put them within reach of the robot.
Only a handful of articles this time and the biggest one of them, which I’ll start with, is deceptively underwhelming.
CRISPR isn’t a new discovery but it was only recently that it has been put to its current use and its importance understood. This article from Quanta Magazine gives a broad overview of the topic. It was originally discovered as a unusual gene in common E. coli and researchers only later realized that the microbes which possess this gene are able to use it to defend themselves against viruses. Effectively the microbes are able to cut out parts of viral DNA and store them so as to recognize these invaders in the future. Even later, researchers realized that this could be adapted into a gene editing tool which would enable scientists to precisely snip out a specific section of DNA and replace it with anything else. Finally, the changes will persist in future generations of the organism. As you can imagine, this makes all kinds of customized organisms much easier to engineer.
This next article from the BBC is much lighter fare. It talks about how the signalling function of the peacock’s elaborate tail may be much subtler than previously imagined. Apparently in addition to the large size and brilliant colors of the famous fantail, it also produces an infrasonic sound that is inaudible to humans but that both male and female peacocks can detect. This effectively allows peacocks to use their fantails to send signals to each other even when not in line of sight.
Ever wondered why we have lots of adjectives that are sight-based, for example all of the different words for even minor variations of colors, but few words for describing smells. In fact, it is difficult to think of many words for describing smells that don’t refer to the source of the smell. This article from The Economist talks about how a study of the Mani people who live in Thailand that this may at least be partially due to cultural bias rather than purely because our sense of smell isn’t as well developed as your sight. Researchers administered smell tests to them and found that they could identify smells much more quickly than a control group of Dutch people and furthermore that their language contains many unique descriptors for smells.