Science

In the coming years, NASA and other space agencies will send humans back to the Moon for the first time since the Apollo Era—this time to stay! To maximize line-of-sight communication with Earth, solar visibility, and access to water ice, NASA, the ESA, and China have selected the Lunar South Pole (LSP) as the location for their future lunar bases. This will necessitate the creation of permanent infrastructure on the Moon and require that astronauts have the right equipment and training to deal with conditions around the lunar south pole.

This includes lighting conditions, which present a major challenge for science operations and extravehicular activity (EVA). Around the LSP, day and night last for two weeks at a time, and the Sun never rises more than a few degrees above the horizon. This creates harsh lighting conditions very different from what the Apollo astronauts or any previous mission have experienced. To address this, the NASA Engineering and Safety Council (NESC) has recommended developing a wide variety of physical and virtual techniques that can simulate the visual experiences of Artemis astronauts.

In the past, the design of lighting and functional vision support systems has typically been relegated to the lowest level of program planning. This worked well for the Apollo missions and EVAs in Low Earth Orbit (LEO) since helmet design alone addressed all vision challenges. Things will be different for the Artemis Program since astronauts will not be able to avoid having harsh sunlight in their eyes during much of the time they spend doing EVAs. There is also the challenge of the extensive shadowing around the LSP due to its cratered and uneven nature, not to mention the extended lunar nights.

Artist’s rendering of the Starship HLS on the Moon’s surface. NASA has contracted with SpaceX to provide the lunar landing system. Credit: SpaceX

In addition, astronaut vehicles and habitats will require artificial lighting throughout missions, which means astronauts will have to transition from ambient lighting to harsh sunlight and/or intense darkness and back. Since the human eye has difficulty adapting to these transitions, it will impede an astronaut’s “function vision,” which is required to drive vehicles, perform EVAs safely, operate tools, and manage complex machines. This is especially true when it comes to rovers and the lander elevator used by the Starship HLS – both of which will be used for the Artemis III and IV missions.

As Meagan Chappell, a Knowledge Management Analyst at NASA’s Langley Research Center, indicates, this will require the development of new functional vision support systems. That means helmets, windows, and lighting systems that can work together to allow crews to “see into the darkness while their eyes are light-adapted, in bright light while still dark-adapted, and protects their eyes from injury.” According to the NESC assessment, these challenges have not been addressed, and must be understood before solutions can be implemented.

In particular, they indicated how functional vision and specific tasks for Artemis astronauts were not incorporated into system design requirements. For example, the new spacesuits designed for the Artemis Program – the Axiom Extravehicular Mobility Unit (AxEMU) – provide greater flexibility so astronauts can walk more easily on the lunar surface. However, there are currently no features or systems that would allow astronauts to see well enough when transitioning between brilliant sunlight into dark shadow and back again without losing their footing.

The NESC assessment identified several other gaps, prompting them to recommend that methods that enable functional vision become a specific and new requirement for system designers. They also recommended that the design process for lighting, windows, and visors become integrated. Lastly, they recommended that various physical and virtual simulation techniques be developed to address specific requirements. This means virtual reality programs that simulate what it is like to walk around the LSP during lunar day and night, followed by “dress rehearsal” missions in analog environments (or both combined!).

Astronauts operating around the Lunar South Pole. Credit: NASA

As Chappell summarized, the simulations will likely focus on different aspects of the mission elements to gauge the effectiveness of their designs:

“Some would address the blinding effects of sunlight at the LSP (not easily achieved through virtual approaches) to evaluate [the] performance of helmet shields and artificial lighting in the context of the environment and adaptation times. Other simulations would add terrain features to identify the threats in simple (e.g., walking, collection of samples) and complex (e.g., maintenance and operation of equipment) tasks. Since different facilities have different strengths, they also have different weaknesses. These strengths and limitations must be characterized to enable verification of technical solutions and crew training.”

This latest series of recommendations reminds us that NASA is committed to achieving a regular human presence on the Moon by the end of this decade. As that day draws nearer, the need for more in-depth preparation and planning becomes apparent. By the time astronauts are making regular trips to the Moon (according to NASA, once a year after 2028), they will need the best training and equipment we can muster.

Further Reading: NASA

The post NASA is Considering Designs and Simulations to Prepare Astronauts for Lighting Conditions Around the Lunar South Pole appeared first on Universe Today.

Here physicist Brian Greene argues with Sam Harris about approaches to dispelling false beliefs, aka religion. Greene argues that simply acquainting people with science will make them less religious (or at least he implies it), and avers that some New Atheists have been ineffective because they call religious people “stupid”. (That’s not so true!). Harris, however, says that the “carrot” attitude of Greene (and Greene really doesn’t use a carrot because he doesn’t criticize religous belief at all) may not be as effective as Harris’s “stick”, which is simply rational argument about what is true and open criticism of the harms of religion. As Sam says, it’s false to assert that you can’t reason people out of religion because he’s seen it happen. So have I.

Sam notes what seems to be the case: Greene just doesn’t want to be the “go-to guy for why you can’t have your cake and eat it too in the matter of science and religion.”  On the other hand, Sam notes that in some ways religion is bad for science. For example, some religious beliefs are inimical to understanding science, including accepting global warming. And of course creationism is still with us in the form of ID.  Sam then asks whether Greene shouldn’t be pushing harder against such inimical religious beliefs. Greene responds that in physics he doesn’t encounter that kind of religious mishigass, which is found more in biology. It’s more than that, though, because I believe that in the past Greene, as one of the organizers of the World Science Festival, has participated in osculating the rump of faith. As I wrote in 2020:

On the other hand [Greene] takes lots of money from the John Templeton Foundation to run the World Science Festival, and there’s always some Templeton-sponsored events that reconcile religion and science or enable “spirituality”.  In fact, Dan Dennett withdrew from a Festival panel when he learned it was backed by Templeton (see the first link in this sentence). And Greene has always been reluctant to say anything bad about religion, despite the fact that he seems to be an atheist. Although he’s said that “there’s much in New Atheism that resonates with me“, he’s admitted that his strategy is less confrontational and less antagonistic than scientists like Dawkins. In fact, as we see below, it no longer seems the least confrontational and antagonistic, but rather worshipful.

There’s more, but I think that one element in Greene’s reticence is knowing that if one criticizes religion, one loses popularity. The fastest way to erode one’s acclaim as a science writer or popularizer is to criticize religion, even if you do it separately from talking about science. Neil deGrasse Tyson has also learned that lesson.

 

An AI model that understands the interplay between human body language, speech and emotion enables digital avatars to move more realistically when speaking

Digital healthcare consultations are not enough for a safe assessment of tonsillitis, according to a new study. Reliability will not be sufficient, thus increasing the risk of over- or under-treatment of a sore throat.

By the end of the century, most of the US outside the high mountains may never see deep snow cover the ground, with consequences for water storage as well as for the life on and beneath the snow

There is growing interest in exploring ways to counteract global warming by intervening in the atmosphere and the oceans, but planned trials are highly controversial

Several prototype aircraft that are intended to bring back commercial supersonic travel have been making big strides in recent years – but it is unknown how well the return of Concorde-like flights will go down with customers

The time to start speaking out to defend vaccines from RFK Jr. is now.

The post Dr. Marty Makary, What Are You Going To Do If RFK Jr. Demands That Revoke Approval For Vaccines? first appeared on Science-Based Medicine.

A research group has analyzed the digital ecosystem of 11- to 12-year-old children across the Basque Autonomous Community, and concluded that two out of three own a smartphone. They use smartphones mainly to talk to family and friends. The researchers also point out that, at that age, access to social media mainly focuses on watching videos and not on generating content.

Bio-inspired wind sensing using strain sensors on flexible wings could revolutionize robotic flight control strategy. Researchers have developed a method to detect wind direction with 99% accuracy using seven strain gauges on the flapping wing and a convolutional neural network model. This breakthrough, inspired by natural strain receptors in birds and insects, opens up new possibilities for improving the control and adaptability of flapping-wing aerial robots in varying wind conditions.

Bio-inspired wind sensing using strain sensors on flexible wings could revolutionize robotic flight control strategy. Researchers have developed a method to detect wind direction with 99% accuracy using seven strain gauges on the flapping wing and a convolutional neural network model. This breakthrough, inspired by natural strain receptors in birds and insects, opens up new possibilities for improving the control and adaptability of flapping-wing aerial robots in varying wind conditions.

On December 23m I called attention to the huge amount of money that the John Templeton Foundation (JTF) was throwing at biology projects giving evidence of “purpose and agency” in organisms. For example, one grant given to a group of investigators, titled “Agency, directionality, and foundations for a science of purpose,” handed out more than $14.6 million! And one of the few areas in biology they’re funding again next year is, yes, projects on the “science of purpose”, to wit:

Science of purpose. We are looking for experimental and theoretical research projects that will provide insight into the purposive, goal-directed, or agential behaviors that characterize organisms and various components of living systems. Researchers who have familiarity with our ongoing work in this area are especially encouraged to apply.

Now you can easily see how this fits into the JTF’s original aim, which was to find evidence for divinity and spirituality in science. And indeed, I’m sure that’s why they’re funding this area.  But I’ve already argued that the only kind of “purpose” found in organismal behavior is that involved in conscious cogitation, which is present in only a few organisms.  Yes, some behaviors look “purposeful,” as when a bacterium moves toward or away from light, but that’s a purely mechanical response—not the kind that, say, humans have when they decide, “I’m going out for pizza.” And of course there is no goal-directedness or purpose in evolution, which simply sorts out genetic variation based on whether genes leave more or fewer copies of themselves, often leaving more when they adapt their carrier better to the environment.

However, the biologists who get funded for work on “agency” and “purpose” will be the first to tell you that they are not really imputing to organisms the kind of mental “purpose” that some organisms have, nor are they looking for anything numinous or supernatural. Rather, they seem to be whipping up a bunch of word salad that makes it seem that they are overthrowing the neo-Darwinian view that adaptations arise from genetic variants sorted out by their relative contribution to the genes of descendants.  Such researchers pretend that they are making profound new statements about biology and evolution, but when you look at the papers carefully, as I did with one of the influential papers (below) that Templeton funded in its “purpose and agency” program, you find nothing new. In this case, a whole paper touting “purpose” is merely re-describing something known for a long time: organisms can evolve “norms”of reaction”. These are simply the plastic developmental programs that organisms evolve to respond to environmental changes, so that behavior, physiology, and appearance can change when conditions change. That superficially may look like “agency”, but there’s no “will” involved, and nothing beyond genes responding to environments.

The evolution of norms of reaction is not hard to understand. Take one familiar plastic response: mammals like cats that grow longer fur in the winter.  This is due simply to natural selection acting on the DNA to respond to cold temperature by growing thicker fur. And, of course, as we know from all the varieties of dogs and cats with more or less fur, artificial selection can do that, too. We needn’t think about “purpose” or “agency” when we see this, nor need we say, “one purpose of this trait is to keep the cat warm” or “the cat has agency to grow longer fur to keep in warm in winter.”  That kind of talk about “purpose” is only confusing, hiding what really happened during evolution: natural selection for flexible forms of development.

And there are gazillions of traits that you could say look as if organisms have such agency or purpose, but they are all the result of natural selection. If a goat loses its front legs in an accident, it may well eventually walk on its hind legs. To do that, a number of their bones, tendons, and muscles have to be reconfigured to allow adaptive locomotion. But this, too, is a result of evolved plasticity: in the past, injuries may have been common, and those individuals with genes that allowed their development to compensate for those injuries, thus allowing the sufferer to survive and reproduce, outcompeted individuals lacking genes giving their bodies the ability to cope with injuries.

This is nothing new in evolution; people have talked about plasticity and “norms of reaction” (how organisms change to cope with changes in the environment”) for ages, and there are even experiments showing that such coping is due to natural selection.  But authors like those of the paper below, funded by the JTF, gussy up an old concept by calling it “biological agency”, enabling them to get a ton of cash from the JTF.

I see the effort as intellectually confusing and, indeed, hubristic, because surely the authors know what they’re doing. In the next and final installment of this “agency” mishigass, I’ll highlight a paper that calls this kind of effort to task, showing that it really doesn’t show anything new. Yes, I get excited when new concepts and findings appear in biology and especially evolution, but this ain’t one of them.

Click on the headline below to read the paper, which is free (there’s a pdf here):

The Sultan et al. paper is poorly written, full of big words that are supposed to constitute their idea of agency. But let’s see first how they define agency. Excerpts from the paper are indented.

What is agency? Sultan et al. assure us that it isn’t anything supernatural, but what it really is comes down to “self-regulation” that, in the end, simply amounts to the norms of reaction of an organism.

Living systems have evolved to be robust, responsive, flexible, self-synthesizing and self-regulating. This dynamic flexibility is manifest across diverse levels of biological organization, from cells, to tissues, to entire organisms, to reproductive lineages, to social colonies, and throughout a variety of organismal activities—from molecular signaling pathways to morphogenetic, metabolic, immune, endocrine, and behavioral systems. We use the term biological agency to refer to this suite of robust processes that is constitutive of living systems (See Box 1). Biological agency, in this sense, is the capacity of a system to participate in its own persistence, maintenance, and function by regulating its own structures and activities in response to the conditions it encounters.[69] Attributing agency to a biological system is based on natural, empirically determined processes and connotes neither consciousness nor deliberate intention.

or

Agency is a dynamical property of a system.[162] It consists in the system’s capacity to transduce, configure, and respond to the conditions it encounters. Crucially, agential systems are capable of maintaining functional stability in response to conditions that would otherwise compromise their viability.

Try as I might, I cannot see a distinction between this farrago of fancy words and good old “norms of reaction”.  “Self regulation” is simply the end result of natural selection acting on organisms so that when the environment changes, they respond through their evolved developmental systems in an adaptive way. Note that the authors explicitly rule out “purpose” of “deliberate intention” in the “consciousness” sense here.  Ergo, “maintaining functional stability in response to conditions that would otherwise compromise their viability” is just like a cat growing longer fur in the winter, but it sure is a fancy way of saying it.

Here some examples the authors adduce for “agency”:

Polypterus fish reared in a terrestrialized environment in which fish are forced to walk on their pectoral fins rather than swim, adjust—within a lifetime—not just their behavior, gait and posture but also their skeletal features, in ways that parallel the fossil record of tetrapods’ ascendance onto land.[136] Tadpoles exemplifying the ancestral detrivorous life style and associated gut morphology will adjust the latter if forced to consume a carnivorous diet, in ways that partly parallel evolved changes in specialized carnivorous lineages.[137] Examples such as these suggest that interactions between developmental systems and environmental circumstance may bias the production of phenotypic variation in the face of novel or stressful environments toward functional, integrated, and possibly adaptive variants.

No, the phenotypic direction isn’t “biased” by anything but natural selection. Polypterus fish live in shallow water and have lungs, and it’s possible that their ancestors evolved to walk on their fins to get around in that shallow water or even to leave the water for brief periods of time if their ponds are drying up and they need to get to another pool of water.  Or, it’s even possible that this norm of reaction isn’t evolved at all, but simply the result of an organism struggling to move when that’s the only alternative it has. Here’s what it looks like:

Try that with a goldfish! Why do Polypterus show “agency” in this way but not goldfish? Probably because of the evolutionary background of this species, which is sometimes regarded as an example of the kind of fish that evolved into terrestrial teterapods. But what “agency” are they showing? Likewise, it’s easy to see how tadpoles could occasionally encounter a situation in which there is more “meat” (other organisms or their remains) to eat than there is non-animal detritus. In that case, tadpoles able to evolve a way to change their digestion in such a circumstance would leave more offspring than those that couldn’t. Of course for this system to work, the environment would occasionally have to change in a way that would give organisms like this an advantage (it doesn’t have ot change every generation).  If organisms evolved a developmental system to adapt to environmental changes that couldn’t conceivably have occurred, then we’d have something to talk about! But I know of no such cases.

To justify their “new” approach, the authors give examples of three phenomena that, they say, can’t be explained by conventional neo-Darwinism:

1). Genome-wide association studies (GWAS), in which genes for traits are identified by looking at which genetic variation in an entire genome is correlated with variation in a trait, often reveal “too few genes”.  For example:

In the case of body weight, for example—a biomedically critical trait in the context of obesity, insulin resistance and type 2 diabetes—115 genetic loci that showed significant statistical association with body mass index (BMI) collectively explained less than 3% of the variation among adults,[8] and a meta-analysis based on an enormous sample of 700,000 individuals (conferring great statistical power) still explained only 6% of BMI variation[9] despite using a high-dimensional correlation matrix that is known to inflate these estimates.[10] While such extremely large studies may incrementally add to the variance explained by identifying additional loci of small effect through sheer statistical force, over 90% of (a) phenotypic variation for BMI and (b) risk of type 2 diabetes remains unaccounted for,[11, 12] pointing to a more fundamental issue.

And yet heritability studies, involving simple correlation of BMI between relatives is measured, show that between 40% and 70% of the variation of that trait among individuals is due to variation in genes. We can find only 6% of those genes, so where are the rest?  One explanation is that there are many genes affecting BMI whose effects are too small to be measured by GWAS, which requires pretty big effects to find a genetic region affecting a trait. Further, GWAS analyses rely entirely on SNPs (single nucleotide polymorphisms in DNA sequence), and are unable to detect duplications and deletions, which we know make a contribution to human trait variation (see references here, here, and here). Finally, GWAS is unable, except in vary large samples, to detect rare genes, and yet given the size of the genome, everyone has quite a few “rare” genes.  When you use large samples, as they have done for human height, the missing heritability diminishes to almost zero: the genetic variation detected by GWAS gives predictions that are almost the same as that based on standard heritability studies.

The authors add this:

Biomedical researchers concerned about the limits of the GWAS approach are therefore increasingly calling for conceptually broader studies directly addressing processing pathways that modulate gene function and hence phenotypic outcomes in individuals via complex gene-environment interactions,[18] environmentally-mediated epigenetic modifications,[19, 20] and physiological and developmental feedback systems such as microbiome composition, which changes dynamically in response to the individual’s diet, behavior, and social environment.[21]

Yes, perhaps there are some differences in microbiomes that are responsible here, but there are many traits where there are “missing genes” that cannot be imputed to microbiome inheritance. As for epigenetic modifications and the like beyond bacteria in the gut, those would also show up in GWAS studies, and so can’t constitute “missing genes” (an epigenetic modification occurs at a given site in the DNA, involves a modified base, and is supposedly inherited over at least one generation).

But much of the above is simply gobbledygook: how can “dynamic changes in response to diet, behavior, and social environment” account for missing genetic variation that shows up in heritability studies but not GWAS studies? This could occur only in species in which cultural, nongenetic factors are inherited, like the tendency to eat fatty foods. But these factors are usually ruled out in most heritability (e,g., in flies) and those studies still show a substantial genetic contribution to variation in a phenotype. What the authors consider “agency” here is not clear, but they are doing a service by highlighting a problem that has yet to be solved: “dark heritability.” We don’t know the answer yet, but we have some clues, and time will tell.

2). The authors drag in epigenetics to explain the missing heritability. This second problem is really the same as the first: we have a mismatch between results revealed by GWAS analysis and simple studies of heritability via correlation between relatives.  But this doesn’t solve the problem: it compounds it for two reasons. First, epigenetic modifications of DNA will show up in GWAS and heritability studies, and so don’t constitute “dark genetic variation”. Further, non-coding RNAs, which the authors further use to explain missing variation, are also inherited.  Finally, and most important, epigenetic modifications of DNA resulting solely from the environment (and not coded for themselves in the genome) almost never persist for more than two or three generations, and thus can’t explain a persistent appearance of “adaptive change” over evolution. Nor are epigenetic modifications usually adaptive, and they can be maladaptive (as in the “Dutch famine trauma”), because they are not evolved but simply the effect of the environment on a genome not adapted to changes in that environment.

Here is one example the authors use to show agency via purported epigenetic change:

An experimental example using isogenic plants points to part of what may be missing. In one series of experiments with the common herb Polygonum, parent plants of the same genetic line were either drought-stressed or given ample water. When their offspring were grown in identical, dry, conditions, they developed differently: the offspring of drought-stressed parents produced significantly larger and more rapidly-extending root systems than those of the moist-grown parents, an inherited phenotypic effect that resulted not from a genetic difference but in response to parental conditions.

“Isogenic” means that all the plants were genetically identical. And yes, it’s hard to imagine that offspring have a way of genetically “knowing” whether their parents experienced drought, though there could be cytoplasmic effects.  So this looks like agency, and may be due to adaptive epigenetic modification.  But this is the exception, rather than the rule.

3.) This is the kicker: neo-Darwinism cannot, say the authors, explain the origins of “novel, complex traits”. Here we have one of the assertions of intelligent design, but although there’s no designer, the authors’ claim about the impotence of neo-Darwinism in producing complex adaptations is simply wrong (they are implying, I think, that organisms are somehow using their AGENCY to develop those complex traits. Here’s the assertion:

The origin of novel complex traits constitutes a central yet largely unresolved challenge in evolutionary biology.[61] Ever since the founding of evolutionary biology one of the discipline’s core motivations has been to understand such elaborate innovations as the vertebrate eye, the insect wing, or the mammalian placenta, traits whose origins transformed the diversity of life on earth. Yet conventional approaches to understanding evolutionary change have provided few opportunities to make significant headway.[62] Of the four evolutionary processes conventionally recognized—natural selection, genetic drift, migration, and mutation, the first three can only sort among existing variants and their distribution within and among populations, but by themselves cannot bring about novel features.[63] This privilege is instead restricted to mutation, yet all attempts to explain the evolution of novel complex traits solely via the coincident origin, spread, and fixation of one beneficial mutation at a time have failed.

Sorry, but this resembles what comes out of the south end of a cow looking north. There is no conceptual reason that sorting out existing and new genetic variants via conventional natural selection is impotent to produce complex traits. The problem is that we simply weren’t there when many complex traits evolved, and so don’t know the genes involved, the selection pressures involved, or even the developmental pathways involved in producing the traits.

I know of only one attempt to get at this problem, and that involved the evolution of the camera eye. This was the work of Nilsson and Pelger summarized in a delightful summary by Richard Dawkins called “The eye in a twinkling“.  Using conservative (“pessimistic”) assumptions about mutation rates, heritabilities, and the number of developmental steps required to transform a light-sensitive spot into a complex “camera eye” with a lens, retina, and cornea (viz., what we and some cephalopoods have), Nilsson and Pelger found out that the evolution of this assuredly complex trait took around 400,000 generations. As Dawkins noted:

Assuming typical generation times of one year for small animals, the time needed for the evolution of the eye, far from stretching credulity with its vastness, turns out to be too short for geologists to measure. It is a geological blink.

And so it might be with other traits, like wings or placentas. The problem is making an appropriate model, and that is hard or impossible without knowing how the trait evolved (we have some idea with the eye, as Dawkins notes, hearkening back to Darwin, who first raised the “eye problem”.) But without such models, it’s almost deceitful to say that we need a new paradigm to explain the evolution of complex traits. (In fact, we can see the evolution of complex traits—like whales evolving from land ungulates in a mere 10,000 years. And that is surely due to selection, though we can’t say with assuredness that conventional neo-Darwinism was involved. But our ignorance does not justify us trying to depose a well-established paradigm, and one that works very quickly in the case of artificial selection (genetic analysis of adaptations invariably shows that changes in the DNA are involved).  Are dog breeds all due to epigenetic modifications of DNA or “agency” in the ancestral wolf? I don’t think so!)

I’ve already gone on too long, but if this paper is typical of the kind of research the JTF is funding as evidence for agency and purpose, it’s throwing its money down the toilet,.

Oh, and one last beef. When I saw this claim in the Sultan et al. paper, I was astonished:

In Maize, for instance, the “profound” architectural and reproductive changes that distinguish cultivated Maize from its wild progenitor, Teosinte, resulted not from novel mutants but from the response of a complex epistatic network to the atmospheric CO2 and crowded planting conditions encountered during the species’ early cultivation.[155]

What? This change, from the grass teosinte on the left to modern corn on the right (hybrid is in the middle) has nothing to do with novel mutations?

John Doebley, CC BY 2.5, via Wikimedia Commons

I looked up reference 155 and found this:

For example, genetic research shows that once-emphasized conventional assumptions about morphological change—e.g., that the change was driven mainly by human selection for rare mutants of a few single genes that were deleterious in wild plants and favorable in field environments or by selection for new, advantageous mutations that appeared postcultivation—have, for some major traits, been supplanted by different and/or more complex processes. These processes include (i) regulatory changes that targeted diverse developmental pathways and led to changes in gene expression (e.g., how, when, and to what degree existing genes are expressed through changes in the amount of mRNA during transcription); (ii) extensive rewiring of transcriptomic and coexpression networks; (iii) in an increasing number of wild progenitors, the presence and availability to the first cultivators of preexisting, nondeleterious genetic components for major domestication traits (known as “cryptic genetic variation”) that induce trait variation only under specific environmental or genetic conditions; and (iv) deviations from simple Mendelian expectations.

Every change mentioned involves mutations, whether they be structural, regulatory, or “cryptic” (genes showing their effects only under limited conditions). There is nothing new here, merely an explication of how artificial selection on teosinte involved a variety genetic changes.  There is NO AGENCY in teosinte, not even construed as broadly as Sultan et al. do.

In the end, the paper seems to be much ado about nothing, which, in the last chapter (maybe tomorrow) another author will analyze critically, showing that there’s no “there” there.

I know many people won’t be interested in this analysis, but I wanted to get it on the record because so many people are hearing that not only is neo-Darwinism a pretty useless paradigm for understanding adaptation, but now are hearing as well that some nebulous “purpose” and “agency” are involved. As usual, Templeton’s money has only muddied the water.

 

h/t: Luana for her explanations of GWAS.

Most of the neutron stars we know of have a mass between 1.4 and 2.0 Suns. The upper limit makes sense, since, beyond about two solar masses, a neutron star would collapse to become a black hole. The lower limit also makes sense given the mass of white dwarfs. While neutron stars defy gravitational collapse thanks to the pressure between neutrons, white dwarfs defy gravity thanks to electron pressure. As first discovered by Subrahmanyan Chandrasekhar in 1930, white dwarfs can only support themselves up to what is now known as the Chandrasekhar Limit, or 1.4 solar masses. So it’s easy to assume that a neutron star must have at least that much mass. Otherwise, collapse would stop at a white dwarf. But that isn’t necessarily true.

It is true that under simple hydrostatic collapse, anything under 1.4 solar masses would remain a white dwarf. But larger stars don’t simply run out of fuel and collapse. They undergo cataclysmic explosions as a supernova. If such an explosion were to squeeze the central core rapidly, you might have a core of neutron matter with less than 1.4 solar masses. The question is whether it could be stable as a small neutron star. That depends on how neutron matter holds together, which is described by its equation of state.

Neutron star matter is governed by the Tolman–Oppenheimer–Volkoff, which is a complex relativistic equation based on certain assumed parameters. Using the best data we currently have, the TOV equation of state puts an upper mass limit for a neutron star at 2.17 solar masses and a lower mass limit around 1.1 solar masses. If you tweak the parameters to the most extreme values allowed by observation, the lower limit can drop to 0.4 solar masses. If we can observe low-mass neutron stars, it would further constrain the TOV parameters and improve our understanding of neutron stars. This is the focus of a new study on the arXiv.

Previous searches for low-mass neutron stars. Credit: Kacanja & Nitz

The study looks at data from the third observing run of the Virgo and Advanced LIGO gravitational wave observatories. While most of the observed events are the mergers of stellar-mass black holes, the observatories can also capture mergers between two neutron stars or a neutron star and a black hole companion. The signal strength of these smaller mergers is so close to the noise level of the gravitational wave detectors that you need to have an idea of the type of signal you’re looking for to find it. For neutron star mergers, this is complicated by the fact that neutron stars are sensitive to tidal deformations. These deformations would shift the “chirp” of the merger signal, and the smaller the neutron star, the greater the deformation.

So the team simulated how sub-white-dwarf mass neutron stars would tidally deform as they merge, then calculated how that would affect the observed gravitational chirp. They then looked for these kinds of chirps in the data of the third observation run. While the team found no evidence for small-mass neutron stars, they were able to place an upper limit on the hypothetical rate of such mergers. Essentially, they found that there can be no more than 2,000 observable mergers involving a neutron star up to 70% of the Sun’s mass. While that might not seem like much of a limit, it’s important to remember that we are still in the early stages of gravitational wave astronomy. In the coming decades, we will have more sensitive gravitational telescopes, which will either discover small neutron stars or prove that they can’t exist.

Reference: Kacanja, Keisi, and Alexander H. Nitz. “A Search for Low-Mass Neutron Stars in the Third Observing Run of Advanced LIGO and Virgo.” arXiv preprint arXiv:2412.05369 (2024).

The post Neutron Stars With Less Mass Than A White Dwarf Might Exist, and LIGO and Virgo Could Find Them appeared first on Universe Today.

Athayde Tonhasca Júnior has returned with one of his patented text-and-photo stories of biology.  Athayde’s captions are indented, and you can enlarge his pictures by clicking on them.

Gone with the wind

As the sun rose on the morning of 28 October 2013, a painted lady butterfly (Vanessa cardui) came out of nighttime torpor, spread its wings to warm up and start a busy day. Were the butterfly to be conscious and self-aware, it would know right away it had gone through a rough patch. Its wings were worn out and ragged in places. If the butterfly looked around, it would see it had company: other painted ladies, all equally battered, mingled nearby. They were on a beach fringed by unfamiliar vegetation and, curiouser and curiouser, the sea seemed to be on the wrong side. It didn’t look at all like West Africa, from where they took off 5 to 8 days before. The perceptive butterfly would be right: they had ended up in French Guiana, over 4,200 km away from home across the Atlantic Ocean.

The painted lady is one of the most cosmopolitan of all butterflies, absent only from Antarctica and South America © Muséum de Toulouse, Wikimedia Commons:

Painted ladies are committed frequent flyers, constantly on the move to keep up with seasonal food plants. Every spring they set out from tropical Africa to Europe across the Sahara Desert and the Mediterranean Sea, only to go back in the autumn. The 15,000-km round trip of successive generations between Africa and Europe is the longest migratory flight recorded for butterflies. But crossing the Atlantic Ocean, as registered by Suchan et al. (2024), is a much tougher challenge altogether: no stopovers for feeding, no respite from the weather. How did the painted ladies make it through the gruelling journey alive?

Routes of painted lady spring migration from North Africa to Europe © Sémhur, Wikimedia Commons:

A fellow traveller, the monarch butterfly (Danaus plexippus), may offer some clues. Every year, monarchs depart from their breeding grounds in southern Canada and northern USA in September and October, arriving at their overwintering sites in Central Mexico in November. Migrating monarchs cruise at energy-saving speeds of about 9 km/h, slower than a person jogging (although there’s a quite a large variation in butterflies’ speed estimates), so they have to slog away to manage distances of over 4,000 km.

Monarch butterfly southbound migration patterns © U.S. Forest Service:

For some insects such as dragonflies and damselflies (Odonata), flight is bimotoric, that is, controlled by forewings and hindwings. Others such as grasshoppers, crickets and related species (Orthoptera) have posteromotoric flight (driven by hindwings). Butterflies and moths (Lepidoptera) are anteromotoric fliers: their flight is controlled primarily by the forewings (Dudley, 2002). But hindwings don’t have a secondary role in butterflies’ locomotion: they are exceptionally well-developed and are coupled with the forewings to flap in synchrony, so that butterflies in general have the largest wing area relative to body mass of all flying insects and perhaps all flying animals, a feature of great help for migrating species.

An efficient flying machine: a female monarch © Kenneth Dwain Harrelson, Wikimedia Commons:

Still, flapping their wings alone would not do: fat reserves would soon be depleted. So, monarchs use skills familiar to aircraft pilots; they glide, taking advantage of air currents and thermals. By holding their wings motionless, their fore- and hindwings overlapping to form a single aerodynamic surface, monarchs gain altitude by soaring in rising air currents, just like birds do. This technique is the most energy-efficient travelling method regarding distances travelled. With good weather and tail winds, monarchs can soar to at least 300 m above the ground and glide for very long distances (Gibo & Pallett, 1979).

Monarchs, birds and glider pilots fly towards a cliff or building to be carried over the top of the obstacle by the deflected air and rise to a higher altitude © Aerospaceweb.org:

Suchan et al. (2024) estimated that painted ladies’ travel would be limited to about 780 km without refuelling. Even if they could feed and despite favourable winds, they wouldn’t go beyond 1,900 km by flapping their wings. Painted ladies must have glided along the northeasterly trade winds, the prevailing winds from West Africa to northwestern South America – the same winds that helped the Portuguese and Spanish to colonize the New World. Based on what has been observed for monarchs, painted ladies must have glided about 85% of the time taken for their trans-continental flight. This dispersal ability could explain the sudden appearance of gaggles of them in places as diverse as the French Riviera, Gaza, Madagascar, the Caribbean, Pacific Islands, and in Siberia, above the Arctic Circle (Shields, 1992):

A model of wind trajectories 48 h before painted ladies were observed in French Guiana © Suchan et al., 2024:

Big and conspicuous wings allow butterflies to travel far, but they also attract hostile characters such as hungry birds. To reduce their chances of ending their lives as juicy morsels, butterflies must take evasive actions. Their well-developed hind wings allow them to make abrupt turns with just a couple of wing flaps, giving them outstanding manoeuvrability. Most butterflies fly erratically, often zig-zagging with no discernible patterns. If you ever tried to catch a butterfly in the air, you know how expertly they evade pursuers. Irregular, chaotic flight patterns can frustrate and discourage the most relentless predator, who quite likely would give up the chase by pragmatically convincing itself in a sour-grapes fashion that the intended prey is ‘mostly wrapper and little candy’ (Jantzen & Eisner, 2008).

A gentleman failing to impress the ladies with his hunting skills. Catching butterflies in Venetian canal, 1854 © Antonio Rotta, Wikimedia Commons:

Butterflies elicit feelings of vulnerability and tenderness, but aesthetics are not good ecological yardsticks. These insects are well-adapted to the vagaries of life, including inclement weather, food deprivation and threat of predation. Some species are perfectly capable of travelling – voluntarily or not – distances that would defeat tougher-looking creatures. These feats of endurance must be relevant for the dispersal and colonisation of hitchhiking propagules such as spores and pollen, but such effects are yet to be extensively investigated. Meanwhile, we may carry on appreciating butterflies’ beauty, knowing that their perceived fragility is deceiving.

Butterflies are not the delicate creatures of our imagination © Samuel Hubbard Scudder, 1881, Wikimedia Commons:

It is Thursday, December 26, 2024, Boxing Day, the second day of Chanukah, and, most important, the second Day of Coynezaa.

The Hili dialogue will be very short today because I prepare most of them the day before, and yesterday was Christmas, when I took a well-deserved break.  We will have a science post and a readers’ wildlife post, but the full Monty won’t be on tap until tomorrow.  So first, here’s Hili (and Szaron). Hili is chewing out the sub-editors

Hili: What do our readers like best? A: I don’t know, I never thought about it. Hili: That’s what I suspected. In Polish: Hili: Co nasi czytelnicy lubią najbardziej? Ja: Nie wiem, nigdy się nad tym nie zastanawiałem. Hili: Tak podejrzewałam.

And Szaron on his blanket and the poinsettia. No worries: none of the cats gnaw on the plant, whose sap is poisonous.

*One NYT article that readers can quarrel about. It’s by Adam Grant, an organizational psychologist at Penn’s Wharton School, and is called “No, you don’t get an A for effort.” (See it archived here.) It’s an argument that today’s students, who beef about their grades not reflecting their effort, are misguided. While effort may count some, achievement, or merit, is more important—at least for course grades. Excerpts:

After 20 years of teaching, I thought I’d heard every argument in the book from students who wanted a better grade. But recently, at the end of a weeklong course with a light workload, multiple students had a new complaint: “My grade doesn’t reflect the effort I put into this course.”

High marks are for excellence, not grit. In the past, students understood that hard work was not sufficient — an A required great work. Yet today, many students expect to be rewarded for the quantity of their effort rather than the quality of their knowledge. In surveys, two-thirds of college students say that “trying hard” should be a factor in their grades, and a third think they should get at least a B just for showing up at (most) classes.

This isn’t Gen Z’s fault. It’s the result of a misunderstanding about one of the most popular educational theories.

More than a generation ago, the psychologist Carol Dweck published groundbreaking experiments that changed how many parents and teachers talk to kids. Praising kids for their abilities undermined their resilience, making them more likely to get discouraged or give up when they encountered setbacks. They developed what came to be known as a fixed mind-set — they thought success depended on innate talent, and they didn’t have the right stuff. To persist and learn in the face of challenges, kids needed to believe that skills are malleable. And the best way to nurture this growth mind-set was to shift from praising intelligence to praising effort.

The idea of lauding persistence quickly made its way into viral articles, best-selling books and popular TED talks. It resonated with the Protestant work ethic and reinforced the American dream that with hard work, anyone could achieve success.

Psychologists have long found that rewarding effort cultivates a strong work ethic and reinforces learning. That’s especially important in a world that often favors naturals over strivers — and for students who weren’t born into comfort or don’t have a record of achievement. (And it’s far preferable to the other corrective: participation trophy culture, which celebrates kids for just showing up.)

The problem is that we’ve taken the practice of celebrating industriousness too far. We’ve gone from commending effort to treating it as an end in itself. We’ve taught a generation of kids that their worth is defined primarily by their work ethic. We’ve failed to remind them that working hard doesn’t guarantee doing a good job (let alone being a good person). And that does students a disservice.

. . . . This is what worries me most about valuing perseverance above all else: It can motivate people to stick with bad strategies instead of developing better ones. With students, a textbook example is pulling all-nighters rather than spacing out their studying over a few days. If they don’t get an A, they often protest.

. . . Teachers and parents owe kids a more balanced message. There’s a reason we award Olympic medals to the athletes who swim the fastest, not the ones who train the hardest. What counts is not sheer effort but the progress and performance that result. Motivation is only one of multiple variables in the achievement equation. Ability, opportunity and luck count, too. Yes, you can get better at anything, but you can’t be great at everything.

. . . Teachers and parents owe kids a more balanced message. There’s a reason we award Olympic medals to the athletes who swim the fastest, not the ones who train the hardest. What counts is not sheer effort but the progress and performance that result. Motivation is only one of multiple variables in the achievement equation. Ability, opportunity and luck count, too. Yes, you can get better at anything, but you can’t be great at everything.

Is Grant a hardass, too tough on his students? Should effort (which can be gauged to some extent) count for anything when assessing grades? After all, when someone like me used to look at grades on a transcript, say for potential graduate students, I assumed they reflected mastery of the material.

And on meme from Cat Memes:

. . . and my daily post from the Auschwitz Memorial:

Killed with cyanide gas upon arrival at Auschwitz, this French Jewish girl was only eight.

— Jerry Coyne (@evolutionistrue.bsky.social) 2024-12-26T11:37:01.149Z

As part of a project to make mathematics machine-readable, mathematicians have discovered an error in an important proof. Thankfully there was a fix, but the incident highlights the potential for other errors to be lurking in the mathematics literature

The coding that forms the basis of Google’s recent breakthrough in error-correcting quantum computers is facing fierce competition

The James Webb Space Telescope (JWST) was specifically intended to address some of the greatest unresolved questions in cosmology. These include all of the major questions scientists have been pondering since the Hubble Space Telescope (HST) took its deepest views of the Universe: the Hubble Tension, how the first stars and galaxies came together, how planetary systems formed, and when the first black holes appeared. In particular, Hubble spotted something very interesting in 2003 when observing a star almost as old as the Universe itself.

Orbiting this ancient star was a massive planet whose very existence contradicted accepted models of planet formation since stars in the early Universe did not have time to produce enough heavy elements for planets to form. Thanks to recent observations by the JWST, an international team of scientists announced that they may have solved this conundrum. By observing stars in the Small Magellanic Cloud (LMC), which lacks large amounts of heavy elements, they found stars with planet-forming disks that are longer-lived than those seen around young stars in our Milky Way galaxy.

The study was led by Guido De Marchi, an astronomer at the European Space Research and Technology Centre (ESTEC) in Noordwijk, Netherlands. He was joined by researchers from the INAF Osservatorio Astronomico di Roma, the Space Telescope Science Institute (STScI), Gemini Observatory/NSF NOIRLab, the UK Astronomy Technology Centre (UK ATC), the Institute for Astronomy at the University of Edinburgh, the Leiden Observatory, the European Space Agency (ESA), NASA’s Ames Research Center, and NASA’s Jet Propulsion Laboratory. The paper detailing their findings appeared on December 16th in The Astrophysical Journal.

James Webb Space Telescope image of NGC 346, a massive star cluster in the Small Magellanic Cloud. Credit: NASA/ESA/CSA/STScI/Olivia C. Jones (UK ATC)/Guido De Marchi (ESTEC)/Margaret Meixner (USRA)

According to accepted cosmological models, the first stars in the Universe (Population III stars) formed 13.7 billion years ago, just a few hundred million years after the Big Bang. These stars were very hot, bright, massive, short-lived, and composed of hydrogen and helium, with very little in the way of heavy elements. These elements were gradually forged in the interiors of Population III stars, which distributed them throughout the Universe once they exploded in a supernova and blew off their outer layers to form star-forming nebulae.

These nebulae and their traces of heavier elements would form the next generation of stars (Population II). After these stars formed from gas and dust in the nebula that underwent gravitational collapse, the remaining material fell around the new stars to form protoplanetary disks. As a result, subsequent populations of stars contained higher concentrations of metals (aka. metallicity). The presence of these heavy elements, ranging from carbon and oxygen to silica and iron, led to the formation of the first planets.

As such, Hubble‘s discovery of a massive planet (2.5 times the mass of Jupiter) around a star that existed just 1 billion years after the Big Bang baffled scientists since early stars contained only tiny amounts of heavier elements. This implied that planet formation began when the Universe was very young, and some planets had time to become particularly massive. Elena Sabbi, the chief scientist for the Gemini Observatory at the National Science Foundation’s NOIRLab, explained in a NASA press release:

“Current models predict that with so few heavier elements, the disks around stars have a short lifetime, so short in fact that planets cannot grow big. But Hubble did see those planets, so what if the models were not correct and disks could live longer?”

James Webb Space Telescope image of NGC 346, a massive star cluster in the Small Magellanic Cloud. Credit: NASA/ESA/CSA/STScI/Olivia C. Jones (UK ATC)/Guido De Marchi (ESTEC)/Margaret Meixner (USRA)

To test this theory, the team used Webb to observe the massive, star-forming cluster NGC 346 in the Small Magellanic Cloud, a dwarf galaxy and one of the Milky Way’s closest neighbors. This star cluster is also known to have relatively low amounts of heavier elements and served as a nearby proxy for stellar environments during the early Universe. Earlier observations of NGC 346 by Hubble revealed that many young stars in the cluster (~20 to 30 million years old) appeared to still have protoplanetary disks around them. This was also surprising since such disks were believed to dissipate after 2 to 3 million years.

Thanks to Webb’s high-resolution and sophisticated spectrometers, scientists now have the first-ever spectra of young Sun-like stars and their environments in a nearby galaxy. As study leader Guido De Marchi of the European Space Research and Technology Centre in Noordwijk put it:

“The Hubble findings were controversial, going against not only empirical evidence in our galaxy but also against the current models. This was intriguing, but without a way to obtain spectra of those stars, we could not really establish whether we were witnessing genuine accretion and the presence of disks, or just some artificial effects.”

“We see that these stars are indeed surrounded by disks and are still in the process of gobbling material, even at the relatively old age of 20 or 30 million years. This also implies that planets have more time to form and grow around these stars than in nearby star-forming regions in our own galaxy.”

Side-by-side comparison shows a Hubble image of the massive star cluster NGC 346 (left) versus a Webb image of the same cluster (right). Credit: NASA/ESA/CSA/STScI/Olivia C. Jones (UK ATC)/Guido De Marchi (ESTEC)/Margaret Meixner (USRA)/Antonella Nota (ESA)

These findings naturally raise the question of how disks with few heavy elements (the very building blocks of planets) could endure for so long. The researchers suggested two distinct mechanisms that could explain these observations, alone or in combination. One possibility is that a star’s radiation pressure may only be effective if elements heavier than hydrogen and helium are present in sufficient quantities in the disk. However, the NGC 346 cluster only has about ten percent of the heavier elements in our Sun, so it may take longer for a star in this cluster to disperse its disk.

The second possibility is that where heavier elements are scarce, a Sun-like star would need to form from a larger cloud of gas. This would also produce a larger and more massive protoplanetary disk, which would take longer for stellar radiation to blow away. Said Sabbi:

“With more matter around the stars, the accretion lasts for a longer time. The disks take ten times longer to disappear. This has implications for how you form a planet, and the type of system architecture that you can have in these different environments. This is so exciting.”

“With Webb, we have a really strong confirmation of what we saw with Hubble, and we must rethink how we model planet formation and early evolution in the young universe,” added Marchi.

Like many of Webb’s observations, these findings are a fitting reminder of what the next-generation space telescope was designed to do. In addition to confirming the Hubble Tension, the JWST observed more galaxies (and bigger ones!) in the early Universe than models predicted. It also observed that the seeds of Supermassive Black Holes (SMBH) were more massive than expected. In this respect, the JWST is doing its job by causing astronomers to rethink theories that have been accepted for decades. From this, new theories and discoveries will follow that could upend what we think we know about the cosmos.

Further Reading: NASA, The Astrophysical Journal

The post Webb Observes Protoplanetary Disks that Contradict Models of Planet Formation appeared first on Universe Today.

A research team accelerates stretchable technology commercialization with world's first visualization of serpentine structures.

Scientists have developed an innovative therapeutic platform by mimicking the intricate structures of viruses using artificial intelligence (AI).