Praise then darkness, and creation unfinished

Family resemblances are complicated

Sat, 12 Jul 2025 23:10:01 GMT

via oursin, something I found interesting: We still don't understand family resemblance, and some of what we thought we knew is mistaken, or might be.

This article describes research that used data from almost a million people: every Norwegian student who took a standardized test from 2007-2019.

Quoting the article: "The resemblance of twins cannot be reconciled with any model....The resemblance of adoptees cannot be reconciled with any model."

Adjusting a model to account better for twins makes it a poorer match of adoptive relationships, and vice versa. Any attempt to account for one of these moves the model away adopted siblings makes it fit twins less well, and vice versa.
( cut for length )

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two cool science stories

Sat, 28 Jan 2023 20:25:15 GMT

Hominins in Ethiopia had a workshop making hand-axes out of obsidian 1.2 million years ago. This is more than twice as long ago as previous evidence of this kind of focused activity.

The article in Nature goes into a lot more detail, with color illustrations:

The standardized obsidian handaxes provide ample evidence of the repetitive use of fully mastered skills. This must have required a foundation of already developed knowledge and skills.

Present-day humans have some understanding of chimpanzee and bonobo gestures.

This study builds on earlier work showing that at least some gestures are consistent across ape species, and other gestures are consistent only within a species:but a gesture that means "give me that food" in chimp is "groom me" or "carry me" in bonobo.

The difficulty in carrying the research over to humans has been that we use a wider variety of gestures, combined with (spoken or signed) language: there isn't a single gesture for "come closer" or "give me that food." What these researchers did is ask humans to interpret chimpanzee and bonobo gestures, on video, edited to show only the ape gesturing, not what it was responding to, or how another ape responded to it. Humans consistently did better than random chance at identifying the meaning of the gestures.

On the other hand, the best accuracy was about 80%; it goes down for gestures that have more than one within-species meaning, and for gestures that have different meanings to chimps than to bonobos.

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Coelacanth lifespan

Tue, 22 Jun 2021 13:07:06 GMT

A new study shows that coelacanths are long-lived and have the longest gestation period of any known animal.

The previous estimate was a lifespan of 20 years, which this study corrects to a century. The estimated gestation period is five years. The previous record-holder was the frilled shark, with a gestation period of about three and a half years; the mammal with the longest gestation period is the elephant, which carries its young for two years.

These are all estimates based on museum specimens (as was the previous number), but the new values fit better with what's known about other fish that live in similar habitats.

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Reasons not to trust the CDC and FDA

Mon, 14 Sep 2020 18:38:36 GMT

On the Science-Based Medicine blog, David Gorski asks whether we can still trust the CDC and FDA and concludes "I don't know."

For me, this is more evidence that no, we can't: Gorski (aka Orac) has been a voice for "trust the science, don't listen to anecdata" and pointing at CDC recommendations for things like vaccination for a long time. But that was before Trump, when we could trust the CDC to look at the science, not edit the Morbidity and Mortality Weekly Report to make the president look better.

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WEIRD societies and the law of unintended consequences

Wed, 20 Nov 2019 21:38:23 GMT

Here's a paper arguing that the Catholic church's intense* concern with incest, eventually defined broadly enough to include distant cousins and "spiritual kin," explains large parts of WEIRD** culture and psychology: https://science.sciencemag.org/content/366/6466/eaau5141

The correlations, and maybe causality, seems to be that changing the rules on who could marry weakened kinship ties, and that in turn reduced conformity and obedience to elders, and increased individualism and "impersonal prosociality," which seems to mean the tendency to trust and try to help strangers as well as family and friends.

This jumped out at me as "unintended consequences" because the short article in *Science* talked about the Catholic Church's "Marriage and family program," with the implication that this was the result of a deliberate, unified policy--but that phrasing but that turns out to be the authors' coinage for long-term policies against marriages to create alliances between families, and then discouraging second, third, and even sixth cousin marriages and arranged marriages, and encouraging or requiring newly married couples to set up their own households.

Whatever the intentions of the people who created those policies, I'm confident that their goals did not include increasing individualism and independence, while reducing conformity and obedience.

* compared to most other cultures and religions, including other forms of Christianity

**a great acronym, for "Western, educated, industrialized, rich, and democratic"

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Trilobites!

Mon, 21 Oct 2019 02:57:47 GMT

sovay found and posted about a delightful paper about collective behavior in trilobites, 480 million years ago.

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Probiotics may be worse than useless

Mon, 10 Sep 2018 01:24:29 GMT

In an admittedly small study of the effects of probiotics after a course of antibiotics, the gut microbiome took longer to return to normal than in people who didn't take them.

What did help was autologous fecal microbiome transplantation (aFMT), but I'm fairly sure that would cost more, because of the work involved, and require some advance planning: it's not likely to be available to the person whose doctor says "you have pneumonia, I'm calling in an antibiotic prescription."

The lead researcher told the BBC that future probiotics would have to be tailored to individual patients.

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I am one of today's lucky ten thousand

Thu, 22 Mar 2018 02:17:01 GMT

Over on File 770, Ingvar has been posting the serial adventures of Trigger Snowflake, a sort of parody of old sf pulp magazines and the Sad Puppies. In the latest episode, a court forbids someone to express gratitude "except within Venostationary orbit."

In the comments, Ingvar noted that they're not sure how crazily big Venostationary orbit is. So, I googled, and found that someone had posted the answer a few years back: about a million and a half kilometers. The search results also led me to something I found more interesting, Emily Lakdawalla’s discussion of keeping a comsat in stationary orbit over Mars, which she was looking at in terms of communications with Mars landers.

The calculations, and the task, are tricky because planets aren’t actually uniform spheres, producing gravitational irregularities that cause a “geosynchronous” satellite to drift over time. So, the satellites need fuel, mostly to keep them over the equator, but also to keep them from shifting longitude. Mars's gravitational field is more irregular than Earth (in part because of those huge shield volcanoes), making it much harder/more expensive to keep a geo”stationary” satellite in position.

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Jurassic butterflies

Thu, 11 Jan 2018 12:54:40 GMT

sovay pointed to an article saying that butterfly fossils prove that the proboscis evolved a full geologic period before flowering plants did, and asked "So what were they eating with them?" One possibility is carrion. I got curious and googled: The full paper is online. No, they haven't found a fossilized butterfly or moth proboscis: what they have are microfossils of different kinds of scales, pushing the earliest date for Glossata, the moths and butterflies which have those mouth-parts, to the end of the Triassic, way before the evolution of flowering plants.

The authors of the paper think those proboscises evolved originally to drink water, and some butterflies and moths then started using them partly to get nectar from horsetails. So, maybe those long mouthparts drove the evolution of flowering plants, rather than the other way around. There's also an offhand reference (as to something that people in the field already know) to "increased herbivory" of insects, with specifics about leaf-eating.

Meanwhile, the Scientific American article also quotes people saying "maybe not" about significant ancient diversification of Lepidoptera, and one who calls the authors' interpretation "widely speculative"; everyone seems to agree that this is a good area for approach for research, and more microfossils would be useful.

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Coughing and germs

Tue, 08 Oct 2013 17:40:48 GMT

The last few years, there's been a lot of encouragement to cough into your elbow instead of covering your mouth with your hand or a tissue. It sounds good, but does it help?

A team in Edmonton compared different "cough etiquette" maneuvers to see whether they would prevent the spread of viruses. Covering your mouth with both hands, a tissue, a clothed elbow, or the usual , including covering your mouth with both hands, a tissue, a clothed elbow, or a surgical mask are all equally ineffective.

The basic problem is that aerosol drops are too small to be blocked by any of those things.

So that leaves us with vaccination, hand-washing, and staying home when sick, which of course many people can't afford to do. (And that person on the bus who is coughing or sneezing might be reacting to an allergy, which is not contagious.)

As a side note, you have read every scientific study that supports coughing into your elbow. Really. There aren't any.

After noting the problem, the authors encourage research to find evidence-based procedures that do block the transmission of respiratory disease. In the meantime, I think I'm going to start carrying hand sanitizer. If you're in the Northern Hemisphere and haven't already gotten a flu vaccine, they're widely available in the U.S. and Canada (I haven't checked on other countries). If you're in the U.S. and have health insurance, it's probably covered. If you're in Canada, the categories of people who can get it free vary by province.

Conclusions

All the assessed cough etiquette maneuvers, performed as recommended, do not block droplets expelled as aerosol when coughing. This aerosol can penetrate profound levels of the respiratory system. Practicing these assessed primary respiratory hygiene/cough etiquette maneuvers would still permit direct, indirect, and/or airborne transmission and spread of IRD, such as influenza and Tuberculosis. All the assessed cough etiquette maneuvers, as recommended, do not fully interrupt the chain of transmission of IRD. This knowledge urges us all to critically review recommended CE and to search for new evidence-based procedures that effectively disrupt the transmission of respiratory pathogens. Interrupting the chain of transmission of IRD will optimize the protection of first responders, paramedics, nurses, and doctors working in triage sites, emergency rooms, intensive care units, and the general public against cough-droplet-spread diseases.

[Via the Science-Based Medicine blog, tucked in near the end of a piece about osteopathic manipulation.]

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Dwarf galaxies orbiting in a plane

Mon, 07 Jan 2013 18:12:38 GMT

Astronomers studying the Andromeda Galaxy (M31) have found that about 30 dwarf galaxies are orbiting in a single plane, rather than in unrelated orbits as expected.

For several decades, astronomers have used computer models to predict how dwarf galaxies should orbit large galaxies, and every time they found that dwarfs should be scattered randomly over the sky. Powered by supercomputers, these efforts have resulted in simulations of ever-increasing fidelity. None of these computer-created universes have generated dwarfs arranged in a revolving plane like that observed in Andromeda.

“It is very exciting for my work to reveal such a strange structure,” said Anthony Conn of Macquarie University, whose research proved key to this study. “It has left us scratching our heads as to what it means.”

(via The Zingularity)

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Random job duties

Fri, 09 Sep 2011 02:59:00 GMT

Apparently part of my job is assuring people that no, the world is not going to end next year.

Today it was one of the designers, who came to me because I'm a science editor; he had heard some garbled thing about a "dwarf star" that was approaching Earth. It took me a moment to figure out what he was talking about, and that he didn't need an explanation of what a dwarf star is beyond "old and dim, and they're all a long way from here." (Not a long way in astronomical terms, but a long way for the purposes of this discussion.) I did my best, and pointed out that anyone can put all sorts of nonsense on the Internet. My analogy was that I can't even sing, but I could put a video of me singing on YouTube and they wouldn't stop me; someone who knows no science can put nonsense up there claiming to be a scientist.

The friend who had told him this also said something about a Russian, or maybe Chinese, scientist; I pointed out that if it was a real danger, they could point to something in English, and it would be from someone at a place like Harvard, not a random Russian newspaper. (The last I looked, which was a few years ago, Pravda was trying to be the Weekly World News but without Batboy.)

A few weeks ago, I got to do something similar right after the Virginia earthquake; in that case the movie threat was the Yellowstone caldera.

What's explicitly in my job is answering science questions; that's mostly in order to keep errors out of the English/Language Arts books. This means that if someone comes over and says "I have a science question" I will do my best to answer it, including using my Google-fu if necessary (though once or twice when swamped I've suggested they talk to Chris or Marilyn instead). I will freely admit that I mostly enjoy doing this, so I'm not going to start asking whether/how the questions are work-related.

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Radiation and the TSA

Sun, 21 Nov 2010 00:53:28 GMT

Whatever else is true, the TSA is demonstrably lying about the safety of those backscatter machines. A large part of their claim is that the radiation penetrates clothing, but not skin.

Their own sample images prove this false: leg bones are clearly visible.

compilerbitch's post also discusses different kinds of radiation, and how little is known about the effects of some of them. (Comparisons of the relative danger from those machines and from cosmic rays are meaningless if we don't actually understand the danger of cosmic rays.)

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Thinking about winter

Sun, 14 Feb 2010 01:41:45 GMT

Dr. Jeff Masters has a good post on current conditions in the United States of Snow and the likelihood that global warming means we can expect more of the same.

If you don't want to follow the link, the short version is that warmer-than-average winters also tend to be snowier than average. So, not only is all this recent snow not evidence against global warming, but we should expect more of it for a few decades. (Eventually it may get too warm for snow, in at least some places that are getting it now.)

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