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Posts Tagged ‘biology

“We are what we pretend to be, so we must be careful about what we pretend to be”*…

There is just something obviously reasonable about the following notion: If all life is built from atoms that obey precise equations we know—which seems to be true—then the existence of life might just be some downstream consequence of these laws that we haven’t yet gotten around to calculating. This is essentially a physicist’s way of thinking, and to its credit, it has already done a great deal to help us understand how living things work…

But approaching the subject of life with this attitude will fail us, for at least two reasons. The first reason we might call the fallacy of reductionism. Reductionism is the presumption that any piece of the universe we might choose to study works like some specimen of antique, windup clockwork, so that it is easy (or at least eminently possible) to predict the behavior of the whole once you know the rules governing how each of its parts pushes on and moves with the others…

The second mistake in how people have viewed the boundary between life and non-life is still rampant in the present day and originates in the way we use language. A great many people imagine that if we understand physics well enough, we will eventually comprehend what life is as a physical phenomenon in the same way we now understand how and why water freezes or boils. Indeed, it often seems people expect that a good enough physical theory could become the new gold standard for saying what is alive and what is not.

However, this approach fails to acknowledge that our own role in giving names to the phenomena of the world precedes our ability to say with any clarity what it means to even call something alive. A physicist who wants to devise theories of how living things behave or emerge has to start by making intuitive choices about how to translate the characteristics of the examples of life we know into a physical language. After one has done so, it quickly becomes clear that the boundary between what is alive and what is not is something that already got drawn at the outset, through a different way of talking than physics provides…

Physics is an approach to science that roots itself in the measurement of particular quantities: distance, mass, duration, charge, temperature, and the like. Whether we are talking about making empirical observations or developing theories to make predictions, the language of physics is inherently metrical and mathematical. The phenomena of physics are always expressed in terms of how one set of measurable numbers behaves when other sets of measurable numbers are held fixed or varied. This is why the genius of Newton’s Second Law, F = ma, was not merely that it proposed a successful equation relating force (F), mass (m), and acceleration (a), but rather that it realized that these were all quantities in the world that could be independently measured and compared in order to discover such a general relationship.

This is not how the science of biology works. It is true that doing excellent research in biology involves trafficking in numbers, especially these days: For example, statistical methods help one gain confidence in trends discovered through repeated observations (such as a significant but small increase in the rate of cell death when a drug is introduced). Nonetheless, there is nothing fundamentally quantitative about the scientific study of life. Instead, biology takes the categories of living and nonliving things for granted as a starting point, and then uses the scientific method to investigate what is predictable about the behavior and qualities of life. Biologists did not have to go around convincing humanity that the world actually divides into things that are alive and things that are not; instead, in much the same way that it is quite popular across the length and breadth of human language to coin terms for commonplace things like stars, rivers, and trees, the difference between being alive and not being alive gets denoted with vocabulary.

In short, biology could not have been invented without the preexisting concept of life to inspire it, and all it needed to get going was for someone to realize that there were things to be discovered by reasoning scientifically about things that were alive. This means, though, that biology most certainly is not founded on mathematics in the way that physics is. Discovering that plants need sunlight to grow, or that fish will suffocate when taken out of water, requires no quantification of anything whatsoever. Of course, we could learn more by measuring how much sunlight the plant got, or timing how long it takes for the fish-out-of-water to expire. But the basic empirical law in biological terms only concerns itself with what conditions will enable or prevent thriving, and what it means to thrive comes from our qualitative and holistic judgment of what it looks like to succeed at being alive. If we are honest with ourselves, the ability to make this judgment was not taught to us by scientists, but comes from a more common kind of knowledge: We are alive ourselves, and constantly mete out life and death to bugs and flowers in our surroundings. Science may help us to discover new ways to make things live or die, but only once we tell the scientists how to use those words. We did not know any physics when we invented the word “life,” and it would be strange if physics only now began suddenly to start dictating to us what the word means.

The origin of life can’t be explained by first principles: “Why Physics Can’t Tell Us What Life Is.”

See also this interview with Jeremy England, the author of the article linked above (and of the book from which it is excerpted): “The Physicist’s New Book of Life.”

  • Kurt Vonnegut, Mother Night

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As we live and let live, we might spare a thought for Ernest Everett Just; he died on this date in 1941.  A pioneering biologist, academic, and science writer, he contributed mightily to the understanding of cell division, the fertilization of egg cells, experimental parthenogenesis, hydration, cell division, dehydration in living cells, and the effect of ultra violet rays on egg cells.

An African-American, he had limited academic prospects on his graduation from Dartmouth, but was able to land a teaching spot at Howard University.  Just met  Frank R. Lillie, the head of the Department of Zoology at the University of Chicago and director of the Marine Biological Laboratory (MBL) at Woods Hole, Mass.  In 1909 Lillie invited Just to spend first one, then several summers at Woods Hole, where Just pioneered the study of whole cells under normal conditions (rather than simply breaking them apart in a laboratory setting).  In 1915, Just was awarded the first Spingarn Medal, the highest honor given by the NAACP.

But outside MBL, Just experienced discrimination.  Seeking more opportunity he spent most of the 1930s in various European universities– until the outbreak of WW II hostilities caused him to return to the U.S. in late 1940.  He died of pancreatic cancer on this date the next year.

Ernest_Everett_Just

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Written by LW

October 27, 2020 at 1:01 am

“The daily hummingbird assaults existence with improbability”*…

Black Metaltail Hummingbird (Metallura phoebe), Peru

High in the Andes, thousands of meters above sea level, speedy hummingbirds defy near-freezing temperatures. These tiny flyers endure the cold with a counterintuitive trick: They lower their body temperature—sometimes as much as 33°C [over 90°F] —for hours at a time, new research suggests…

Among vertebrates, hummingbirds have the highest metabolism for their size. With a metabolic rate roughly 77 times that of an average human, they need to feed nearly continuously. But when it gets too cold or dark to forage, maintaining a normal body temperature is energetically draining. Instead, the small animals can cool their internal temperature by 10°C to 30°C. This slows their metabolism by as much as 95% and protects them from starvation, says Blair Wolf, a physiological ecologist at the University of New Mexico, Albuquerque.

In this state, called torpor, a bird is motionless and unresponsive. “You wouldn’t even know it was alive if you picked it up,” Wolf says. But when the morning comes and it’s time to feed, he says, the birds quickly warm themselves back up again. “It’s like hibernation but regulated on an even tighter schedule.”…

One of Nature’s (many) marvelous tricks: “To survive frigid nights, hummingbirds cool themselves to record-low temperatures.”

* Ursula K. Le Guin, No Time to Spare: Thinking About What Matters

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As we admire adaptation, we might send closely-observed birthday greetings to Antonie Philips van Leeuwenhoek; he was born on this date in 1632. A largely self-taught man in science, he is commonly known as “the Father of Microbiology“, and one of the first microscopists and microbiologists (he discovered bacteria, protists, sperm cells, blood cells, and numerous structures in animal and plant tissues). A central figure in the Golden Age of Dutch science and technology, his letters to the Royal Society were widely read and richly influential… which is fair dues, as it’s widely believed that van Leeuwenhoek was inspired by illustrations in  Robert Hooke’s earlier book, Micrographia [and here].

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“You cannot store them To warm the winter’s cold, The lad that hopes for heaven shall fill his mouth with mould”*…

[Earlier this month] craving sweets, Colin Purrington remembered the Twinkies.

He’d purchased them back in 2012 for sentimental reasons when he heard that Hostess Brands was going bankrupt and Twinkies might disappear forever.

“When there’s no desserts in the house, you get desperate,” says Purrington, who went down to the basement and retrieved the old box of snack cakes, fully intending to enjoy several…

Like many people, Purrington believed Twinkies are basically immortal, although the official shelf life is 45 days. He removed a Twinkie from the box, unwrapped it — it looked fine — and took a bite. Then he retched. “It tasted like old sock,” Purrington says. “Not that I’ve ever eaten old sock.”

That’s when he examined the other Twinkies. Two looked weird. One had a dark-colored blemish the size of a quarter. The other Twinkie was completely transformed — it was gray, shrunken and wrinkly, like a dried morel mushroom.

He posted photos on Twitter, and they caught the attention of two scientists: Brian Lovett and Matt Kasson, who study fungi at West Virginia University in Morgantown. “Matt is going to want that Twinkie,” thought Lovett, the instant he saw the mummified one.

That’s because, in the past, their lab has tested how well molds grow in Peeps, the classic Easter treat. Fungi actually found it difficult to survive on Peeps, because of the food’s low water content. “In a way, they are kind of like an extreme environment, right?” Kasson notes. “The food industry has crafted the ability to make foods that have a long shelf life.

Still, Kasson says, fungi are everywhere and have an amazing set of chemical tools that let them break down all kinds of substances. “You find fungi growing on jet fuel,” he says…

They reached out to Purrington, who was only too happy to mail them the Twinkies immediately. “Science is a collaborative sport,” he says. “If someone can take this and figure out what was actually growing, I’m all in. I really want to know what species exactly was eating my Twinkies.”

The Twinkies arrived at the lab, and the researchers got to work…

The illuminating (if not appetizing) tale of “A Disturbing Twinkie That Has, So Far, Defied Science.”

* A.E. Housman

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As we stop stockpiling snacks, we might send variously-well preserved birthday greetings to William A. Mitchell; he was born on this date in 1911.  A chemist who spent most of his career at General Foods, he was the inventor of Pop Rocks, Tang, quick-set Jell-O, Cool Whip, and powdered egg whites; over his career, he received over 70 patents almost all of them for processed food items or preparation procedures.

MITCHELL

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Written by LW

October 21, 2020 at 1:01 am

“The body is our general medium for having a world”*…

Leonardo’s Vitruvian Man

The biggest component in any human, filling 61 percent of available space, is oxygen. It may seem a touch counterintuitive that we are almost two-thirds composed of an odorless gas. The reason we are not light and bouncy like a balloon is that the oxygen is mostly bound up with hydrogen (which accounts for another 10 percent of you) to make water — and water, as you will know if you have ever tried to move a wading pool or just walked around in really wet clothes, is surprisingly heavy. It is a little ironic that two of the lightest things in nature, oxygen and hydrogen, when combined form one of the heaviest, but that’s nature for you. Oxygen and hydrogen are also two of the cheaper elements within you. All of your oxygen will set you back just $14 and your hydrogen a little over $26 (assuming you are about the size of Benedict Cumberbatch). Your nitrogen (2.6 percent of you) is a better value still at just forty cents for a body’s worth. But after that it gets pretty expensive.

You need about thirty pounds of carbon, and that will cost you $69,550, according to the Royal Society of Chemistry. (They were using only the most purified forms of everything. The RSC would not make a human with cheap stuff.) Calcium, phosphorus, and potassium, though needed in much smaller amounts, would between them set you back a further $73,800. Most of the rest is even more expensive per unit of volume, but fortunately only needed in microscopic amounts.

Thorium costs over $3,000 per gram but constitutes just 0.0000001 percent of you, so you can buy a body’s worth for thirty-three cents. All the tin you require can be yours for six cents, while zirconium and niobium will cost you just three cents apiece. The 0.000000007 percent of you that is samarium isn’t apparently worth charging for at all. It’s logged in the RSC accounts as costing $0.00.

Of the fifty-nine elements found within us, twenty-four are traditionally known as essential elements, because we really cannot do without them. The rest are something of a mixed bag. Some are clearly beneficial, some may be beneficial but we are not sure in what ways yet, others are neither harmful nor beneficial but are just along for the ride as it were, and a few are just bad news altogether. Cadmium, for instance, is the twenty-third most common element in the body, constituting 0.1 percent of your bulk, but it is seriously toxic. We have it in us not because our body craves it but because it gets into plants from the soil and then into us when we eat the plants. If you are from North America, you probably ingest about eighty micrograms of cadmium a day, and no part of it does you any good at all.

A surprising amount of what goes on at this elemental level is still being worked out. Pluck almost any cell from your body, and it will have a million or more selenium atoms in it, yet until recently nobody had any idea what they were there for. We now know that selenium makes two vital enzymes, deficiency in which has been linked to hypertension, arthritis, anemia, some cancers, and even, possibly, reduced sperm counts. So, clearly it is a good idea to get some selenium inside you (it is found particularly in nuts, whole wheat bread, and fish), but at the same time if you take in too much you can irremediably poison your liver. As with so much in life, getting the balances right is a delicate business.

Altogether, according to the RSC, the full cost of building a new human being, using the obliging Benedict Cumberbatch as a template, would be a very precise $151,578.46. … That said, in 2012 Nova, the long-running science program on PBS, did an exactly equivalent analysis for an episode called ‘Hunting the Elements’ and came up with a figure of $168 for the value of the fundamental components within the human body…

An excerpt from Bill Bryson’s The Body: A Guide for Occupants, via the ever-illuminating Delanceyplace.com: “How much, in materials, would it cost to build a human body?

* Maurice Merleau-Ponty, Phenomenology of Perception

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As we take our vitamins, we might we might send dynamically-evolved birthday greetings to Stephen Jay Gould; he was born on this date in 1941.  One of the most influential and widely read writers of popular science in his generation (e.g., Ever Since Darwin, The Panda’s Thumb), Gould was a highly-respected academic paleontologist, evolutionary biologist, and historian of science.  With Niles Eldridge, he developed the theory of “punctuated equilibrium,” an explanation of evolution that suggests (in contrast with the gradualism that was prevalent until then) that most evolution is marked by long periods of evolutionary stability, which are interrupted– “punctuated”– by rare instances of branching evolution (c.f., the Burgess Shale).

Scientists have power by virtue of the respect commanded by the discipline… We live with poets and politicians, preachers and philosophers. All have their ways of knowing, and all are valid in their proper domain. The world is too complex and interesting for one way to hold all the answers.

Stephen Jay Gould, Bully for Brontosaurus: Reflections in Natural History

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“All poets write bad poetry. Bad poets publish them, good poets burn them.”*…

 

Thunderstorm with the Death of Amelia 1784 by William Williams active 1758-1797

Thunderstorm with the Death of Amelia, by William Williams, 1784. Photograph © Tate (CC-BY-NC-ND 3.0).

 

Readers may recall an earlier nod to William Topaz McGonagall, widely considered to be the worst published poet in British history.  McGonagall, best known for his widely-excoriated verse recounting of “The Tay Bridge Disaster,” distributed his poems, often about momentous events, on handbills and performed them publicly (often, it is reported, to cat calls and thrown food).  And he collected his verse into volumes including Poetic Gems, More Poetic Gems, Still More Poetic Gems, Further Poetic Gems, and Yet Further Poetic Gems.  Imagine your correspondent’s surprise and delight to find a learned appreciation of McGonagall’s place in poetic history:

Not unjustly, McGonagall is rarely mentioned without an epithet: some version of “the worst poet in the English language.” And by any reasonable account, any judgment based on the most universally shared values of poetics, prosody, and taste, there is little to admire in McGonagall. The rest of his corpus shares—replicates, really—the faults of “The Tay Bridge Disaster”: its lapses into bathos, its involuted syntactical structures, its rhymes so slanted as to be more or less horizontal.

There have been worse poets, of course, and as such it would be more accurate to describe McGonagall as the worst famous poet in the English language, a testament in part to the man’s powers of self-promotion and the caprices of literary history. But McGonagall’s notoriety still owes much to the singularly strange power of his own badness. There’s something, I think, in poems like “The Tay Bridge Disaster”—as well as McGonagall’s many poems on his great themes of death and destruction—that is worth examining; something that might redeem him, ever so slightly, from the annals of amusing semi-obscurity; something unsettling about his ostensibly blinkered artistic vision that might help to account for why he lingers as the patron saint of misbegotten verse…

On William Topaz McGonagall, the worst famous poet in the English language: “The Disaster Poet.”

(Readers will find a selection of McGonagall’s poems here.)

* Umberto Eco

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As we bathe in bathos, we might spare a thought for the decidedly more-accomplished poet (and playwright, artist, biologist, theoretical physicist, and philosopher) Johann Wolfgang von Goethe; he died on this date in 1832.  Probably best remembered these days for Faust, he was “the master spirit of the German people,” and, after Napoleon, the leading figure of his age.

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Written by LW

August 28, 2020 at 1:01 am

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