Quite a rich trove of articles this month but once again the really fascinating stuff are in the life sciences.
Easily the most significant and controversial finding of this month’s batch is the discovery in China of a human skull that dates from a million years ago. The skull found in Hubei province and called Yunxian 2 was originally assumed to belong to a member of Homo erectus. New analysis now suggests that it was actually a member of Homo longi who was thought to have lived alongside Neanderthals and Homo sapiens. If true, this sets the timeline of the evolution of large-brained humans back by at least half a million years. Some are using this finding to challenge the established provenance of humans as being from Africa but it’s more likely evidence that there is still so much more that we don’t know.
One of the key symptoms of schizophrenia is auditory hallucinations, hearing things that aren’t there. One explanation for what is going on is that the patients are unable to distinguish between inner speech and external voices. A new study tests this hypothesis using EEG to monitor brain activity while they were asked to internally produce a sound without speaking it out loud and while listening to an audible syllable without doing anything else. The team found that patients known to have auditory hallucinations had brain activity that suggests they experience inner speech as more real than external sounds.
Here’s something that won’t occur to most people but will likely seem like a horror story once they hear about it. Some children suffer from epilepsy so severe that the treatment consists of surgically disconnecting the part of the brain in which the seizures originate from the rest of the brain. Yet the tissue remains intact and remains alive. One team wanted to find out whether the part that gets disconnected still has some awareness. So they took EEG readings of both the intact brain and the disconnected region before the surgery and at regular intervals afterwards. Thankfully the results aren’t horrifying. Electrical activity in the intact portion of the brain showed no changes but in the severed portion, the EEG showed slow rhythms called delta waves which are consistent with deep sleep. So it’s not dead but at least it isn’t fully aware all the time.
Finally here’s an article about similarities in sounds made by birds of different species separated by vast distances and how the phenomenon provides new insight into the development of human language. The researchers found that more than 20 different bird species across four continents produce nearly identical “whining” vocalizations when they spot parasitic birds. They performed playback experiments which showed that birds who hear the calls for the first time will come to investigate the sound. They are then able to learn and reproduce that sound in the future. This suggests a novel pathway for how languages might have developed.
As usual as I like to do a rundown on the scientific prizes every year because it’s downright criminal how little attention the announcements get. The task is a little easier this year because the discoveries they involve should be straightforward for the layman to understand.
I always prefer it when the science news is both highly significant and relatively easy to understand and directly relevant. Most of the articles in this batch seem to fit these criteria.
We’ll start with the news that is the least approachable but it’s really not that bad. Since the James Webb Space Telescope (JWST) started delivering data, the results have seriously challenged longstanding assumptions in cosmology. The latest one is a claim that the mysterious Little Red Dots seen by the telescope is a primordial black hole with the mass of 50 million Suns. The issue is that according to our current understanding of how galaxies are formed, it should be impossible for such massive black holes to form so early in the history of the universe. So this adds more evidence that to the gathering pile that present theories about the birth and expansion of the universe are just wrong.
Next we have the discovery that a single mutation in horses led to them becoming rideable by humans and thence changed the course of history. The gene in question is called GSDMC and the researchers the date of the mutation to about 4,200 years ago. In horses, this mutation is known to reshape vertebrae, improve motor coordination and boost limb strength. They were able to show that the frequency of the mutated GSDMC variant shot from 1% to nearly 100% in a few centuries as humans specifically bred horses with the mutation they spread all across Eurasia.
One uplifting bit of news is the discovery of a process that turns plastic into fuel at 95% efficiency in one step. Other processes already exist but they include dechlorination as a separate step for PVC to avoid releasing toxic compounds. Their new process is apparently do it in a single step and handle mixed PVC materials and polyolefin waste, which includes both polyethylene (PE) and polypropylene (PP), together. There’s no mention of how expensive this is or whether this can be scaled but it still sounds like good news to me.
There’s been a great deal of debate lately about allowing smartphones in classrooms with many countries opting for a ban. This paper which covers a randomized controlled trial involving 17,000 students found that a ban did result in better grades, but the improvement was very minor. Perhaps more significantly, they also found that students exposed to the ban became more supportive of phone-use restrictions, suggesting that a ban might be popular with both parents and students. Yet this is very far from the last word on this issue as others have pointed out that the study fails to account for the possible benefits of using smartphones in schools. This is one area in which many commentators feel like they need to have their say.
We have an even mix this months between science news about the biological sciences and LLMs. Progress!
The most shocking of the bunch is the discovery that so-called sex reversal seems more common in birds than previously thought. The team dissected the bodies of nearby 500 birds of five common Australian species and found sex-revered individuals in all five species at rates of 3% to 6%. Nearly all of these samples were genetically female but had male reproductive organs. However they also found a few genetic males with ovaries and one had evidence of recently having laid an age. This is yet another demonstration that sex is more fluid and mutable than many think but it should be cautioned as this finding applies only to birds.
News on the mRNA vaccine development front has been depressing recently as the Trump administration keeps cracking down on it and cutting funding. This paper shows some of the potential for major medical applications that might be lost. It proposes that a broad-spectrum mRNA-based antiviral could be formulated. It works by activating interferon-stimulated genes that protect cells against viral infection at the cost of possibly causing mild and often self-resolving inflammation. What’s exciting here is that it seems to help make the treated cells resistant to a wide range of different viruses including including the Zika virus, vesicular stomatitis virus, and SARS-CoV-2. As usual this is an extremely early finding and there are many practical issues, but it demonstrates the viability of a completely fresh approach to developing antiviral prophylactics.
Both of the LLM papers are about the impact the deployment of the technology is having on society, possibly in subtle ways. The first one discusses whether ChatGPT in particular is being used by investors to inform their trading decisions. The authors hit upon a novel way to measure this by matching outages of the ChatGPT service with stock trading activity. They show that trading volume does indeed decline when the service is not available and that this effect is stronger for companies which have released corporate news immediately before or during the outage. There’s not much else that can be concluded so far but it does suggest that AI use is widespread and is indeed being used to make investment decisions.
A much more subtle and yet important influence of increasing LLM use among the general public can be seen in this other paper. They attempt to quantity the impact of LLMs on human culture by analyzing human discourse from sources such as YouTube videos and podcast episodes. They claim that they were able to measure an increase in the usage of words commonly used by ChatGPT. As they note, this marks the beginning of a cultural feedback loop in which LLMs are trained on human data yet the widespread usage of LLMs itself reshape how humans use language.
Once again, a good number of biology articles this month but there is one about the Earth’s magnetic field which may be related to the planet bearing life, or it might not.
Starting with that first, the study is about the realization that the strength of Earth’s magnetic field seems correlated with the abundance of oxygen in the atmosphere, roughly rising and falling together over the past billion years or so. The strange thing is that there is no obvious reason why they might be correlated with the best guess being merely that the magnetic field helps to deflect solar wind, thus slowing the loss of oxygen and other gases into space. Another explanation might be that tectonic motions can both affect the geomagnetic field and release nutrients that fuel blooms of oxygen-producing algae.
Next is a development combines both biology and information technology. A private institute has just announced the creation of the first virtual model of a cell. This specific version is designed to predict how stem cells, cancer cells and immune cells respond to drugs, cytokines or genetic perturbations. The obvious benefit is that using a virtual model of the cell is far easier than having to run the experiment using real cells. Everyone will be testing to see how accurate the responses of this particular model will be but this is only the first attempt and future versions are only going to be better.
Then we have this news about an experiment that has dramatically extended the lifespan of mice by giving them monthly injections of an antibody. The antibody in question, X203, works by inhibiting the natural protein interleukin 11. This is a cytokine whose concentration in the body increases with age and is associated with inflammation and cancer. The team claims that interleukin 11 has been observed to work similarly in humans as in mice but of course we still need to what effects this injection has on more subjects beyond mice and what the long-term effects other than extending life would be.
Finally here’s an article that I included because it feels like something right out of the videogame Bioshock to me. It talks about how a specific species of sea slugs are able to gain new abilities by consuming algae with those abilities. For example they are able to gain photosynthesis from the algae when consuming. Instead of digesting the chloroplast cells, they build structures of their own around them, and keep them working. Similarly they are able to store the stinging cells from the sea anemones they consume and deploy them later against their own enemies.
A bunch of cool science stuff this month, all of which stem from biology but touch upon different topics.
The simplest and most directly beneficial of these announcements is the US approving a twice-a-year shot that will completely prevent HIV. This doesn’t quite count as a vaccine as it does need to be taken twice a year but it is the longest lasting protection against HIV yet. In its original form, it’s probably too expensive for widespread use in developing countries but generic copies will eventually become available and that could well mean the end of AIDS.
Ever since it was first identified in the 1980s, the Flynn effect has invited endless speculation on the cause of the increase in intelligence and whether the trend will continue. This new paper uses data from the Norwegian Armed Forces which has administered a general mental ability test on recruits since 1954. It argues that while some types of skills improved over time, notably non-verbal reasoning ability, word reasoning and numerical reasoning abilities decreased over the same period. This suggests that it might not be accurate to say that intelligence in general has increased over time.
Next we have a paper that claims to advance our understanding on how sperm whales communicate. It argues that their codas, the series of clicks that they use to communicate, not only resemble human vowels acoustically but also appears in patterns similar to human language. These findings are used to construct a case that these codas are intentionally controlled and constitute a type of language that we could one day unlock.
Finally here’s a paper that attempts to do the seemingly impossible, study the phenomenon of qualia itself. The team purports to answer the age-old question of whether your ‘red’ is the same as my ‘red’ by doing the following: collect detailed reports about the relations between sensory experiences of various participants; construct what they call qualia structures from the data, meaning embeddings of qualia that represent the similarity or lack thereof of the participants’ judgment of what they have experienced; compares two individuals’ qualia structures in what they call an unsupervised alignment method which doesn’t assume that there are particular correspondences between the structures. The upshot is that the team could align the structures of color-neurotypical group, meaning those who are not color blind and self-report seeing colors normally. They could also align the structures of the color-atypical group despite differences in the type of color blindness within that group. But they could not align the structures between the color-neurotypical and color-atypical group meaning that those structures are too different. It’s hard to say what we can conclude from these results, perhaps that it might be possible to prove that those who experience colors in the same way do actually share the same qualia. But the ambition behind the project is something I can certainly get behind.
A few interesting announcements for this round and once again, it feels that the really cool developments are going on in the life sciences.
By far the most significant bit of news, and one that I’d hoped would be shouted from the rooftops, is the successful use of the CRISPR gene-editing technique to treat a child’s unique mutation. The patient in question was born with a rare disease known as carbamoyl-phosphate synthetase 1 (CPS1) deficiency which usually kills in infancy. In this case, doctors were able to devise a targeted fix to edit DNA in the liver cells, test the treatment in mice, get approval from the FDA and administering the treatment all in a matter of months. They still don’t know if the effect is permanent but for now the patient is well enough to be able to leave the hospital since being born. The key here is the incredible speed of this achievement and the fact that this is a treatment personalized for that specific patient. We should all hope that this is only the first of many such achievements.
Next up is a medical development that feels like something out of science-fiction. An American man, Tim Friede, had for personal reasons exposed him to the venom of a large variety of snakes in escalating doses over the course of 18 years. As a result, he has generated antibodies that are effective against multiple types of neurotoxins. By isolating the antibodies in his blood, researchers have devised a broad spectrum antivenom that should now be almost universally effective against snakebites. If the project comes to fruition, this would be a radical improvement from the current practice of needing to manufacture and stock multiple types of antivenoms in case of emergencies.
The last paper was released a couple of months earlier but I hadn’t noticed it then. It’s about a study conducted on the Hadza, a hunter-gatherer tribe in Tanzania whose nomadic lifestyle is thought to have been unchanged for thousands of years. This makes them an ideal subject to interrogate about human nature before the advent of civilization. In this instance, researchers were interested in whether such peoples are inherently disposed to be egalitarian as some anthropologists contend. They gave the Hadza participants food endowments to be shared with others and studied how fairly they carried out the redistribution. They found that like just about everyone else, the Hadza mostly did not seek perfectly equitable distributions. They tolerated inequality when it benefited but complained about it when they thought it was unfair. As usual, it’s unwise to generalize too broadly from such studies but I’d always thought that stories of pre-civilization peoples being inherently more noble to be too fanciful to be true.