Posts Tagged ‘Life’
“Two obsessions are the hallmarks of Nature’s artistic style: Symmetry- a love of harmony, balance, and proportion [and] Economy- satisfaction in producing an abundance of effects from very limited means”*…
Life is built of symmetrical structures. But why? Sachin Rawat explores…
Life comes in a variety of shapes and sizes, but all organisms generally have at least one feature in common: symmetry.
Notice how your left half mirrors the right or the radial arrangement of the petals of a flower or a starfish’s arms. Such symmetry persists even at the microscopic level, too, in the near-spherical shape of many microbes or in the identical sub-units of different proteins.
The abundance of symmetry in biological forms begs the question of whether symmetric designs provide an advantage. Any engineer would tell you that they do. Symmetry is crucial to designing modular, robust parts that can be combined together to create more complex structures. Think of Lego blocks and how they can be assembled easily to create just about anything.
However, unlike an engineer, evolution doesn’t have the gift of foresight. Some biologists suggest that symmetry must provide an immediate selective advantage. But any adaptive advantage that symmetry may provide isn’t by itself sufficient to explain its pervasiveness in biology across scales both great and small.
Now, based on insights from algorithmic information theory, a study published in Proceedings of the Natural Academy of Sciences suggests that there could be a non-adaptive explanation…
Symmetrical objects are less complex than non-symmetrical ones. Perhaps evolution acts as an algorithm with a bias toward simplicity: “Simple is beautiful: Why evolution repeatedly selects symmetrical structures,” from @sachinxr in @bigthink.
* Frank Wilczek (@FrankWilczek)
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As we celebrate symmetry, we might recall (speaking of symmetry) that it was on this date in 1963 that the Equal Pay Act of 1963 was signed into law by president John F. Kennedy. Aimed at abolishing wage disparity based on sex, it provided that “[n]o employer having employees subject to any provisions of this section [section 206 of title 29 of the United States Code] shall discriminate, within any establishment in which such employees are employed, between employees on the basis of sex by paying wages to employees in such establishment at a rate less than the rate at which he pays wages to employees of the opposite sex in such establishment for equal work on jobs[,] the performance of which requires equal skill, effort, and responsibility, and which are performed under similar working conditions, except where such payment is made pursuant to (i) a seniority system; (ii) a merit system; (iii) a system which measures earnings by quantity or quality of production; or (iv) a differential based on any other factor other than sex […].
Those exceptions (and lax enforcement) have meant that, 60 years later, women in the U.S. are still paid less than men in comparable positions in nearly all occupations, earning on average 83 cents for every dollar earned by a man in a similar role.
“Oh how wrong we were to think immortality meant never dying”*…
The John Templeton Foundation has undertaken a undertaken a deep investigation into the biology, philosophy, and theology of immortality research. Lorraine Boissoneault offers the first in a series of reports on their work…
Around 100,000 years ago, humans living in the region that would come to be called “Israel” did something remarkable. When members of the community died, those left behind buried the dead in a cave, placing some of the bodies with great care and arranging them near colorful pigments and shells. Although burial is so common today as to be almost unremarkable, for ancient humans to exhibit such behavior suggested a major development in cultural practices. The Qafzeh Cave is one of the oldest examples that humans understand death differently than many other creatures. We seem to have an innate desire to mark it with ritual.
It is an unavoidable fact of biology that all organisms die, whether by disease, disaster, or simply old age. Yet our species, Homo sapiens, seems to be the only creature blessed—or cursed—with the cognitive ability to understand our mortality. And thanks to our powerful intelligence, we’re also the only beings to imagine and seek out death’s opposite: immortality.
In religious traditions, spiritual afterlives and reincarnation offer continuation of the self beyond death. In myth and legend, sources of everlasting life abound, from the Fountain of Youth to elixirs of life. Some people seek symbolic immortality through procreation. Others aim for contributions to society, whether artistic, academic or scientific. And still others have pushed the bounds of technology in search of dramatic life extension or a digital self.
Where does this impulse come from?…
Find out: “Pre-life, Afterlife, and the Drive for Immortality,” from @boissolm @templeton_fdn.
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As we internalize eternity, we might recall that it was on this date in 1826 that the HMS Beagle set sail from Plymouth on its first voyage, an expedition to conduct a hydrographic survey of Patagonia and Tierra del Fuego in support of the larger ship HMS Adventure.
The Beagle‘s second voyage (1831-1836) is rather better remembered, as it was on that expedition that the ship’s naturalist, a young Charles Darwin (whose published journal of the journey, quoted above, earned him early fame as a writer) made the observations that led him to even greater fame for his theory of evolution.

“Nothing from nothing ever yet was born”*…
Lacy M. Johnson argues that there is no hierarchy in the web of life…
… Humans have been lumbering around the planet for only a half million years, the only species young and arrogant enough to name ourselves sapiens in genus Homo. We share a common ancestor with gorillas and whales and sea squirts, marine invertebrates that swim freely in their larval phase before attaching to rocks or shells and later eating their own brain. The kingdom Animalia, in which we reside, is an offshoot of the domain Eukarya, which includes every life-form on Earth with a nucleus—humans and sea squirts, fungi, plants, and slime molds that are ancient by comparison with us—and all these relations occupy the slenderest tendril of a vast and astonishing web that pulsates all around us and beyond our comprehension.
The most recent taxonomies—those based on genetic evidence that evolution is not a single lineage, but multiple lineages, not a branch that culminates in a species at its distant tip, but a network of convergences—have moved away from their histories as trees and chains and ladders. Instead, they now look more like sprawling, networked webs that trace the many points of relation back to ever more ancient origins, beyond our knowledge or capacity for knowing, in pursuit of the “universal ancestors,” life-forms that came before metabolism, before self-replication—the several-billion-year-old plasmodial blobs from which all life on Earth evolved. We haven’t found evidence for them yet, but we know what we’re looking for: they would be simple, small, and strange.
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Slime molds can enter stasis at any stage in their life cycle—as an amoeba, as a plasmodium, as a spore— whenever their environment or the climate does not suit their preferences or needs. The only other species who have this ability are the so-called “living fossils” such as tardigrades and Notostraca (commonly known as water bears and tadpole shrimp, respectively). The ability to become dormant until conditions are more favorable for life might be one of the reasons slime mold has survived as long as it has, through dozens of geologic periods, countless ice ages, and the extinction events that have repeatedly wiped out nearly all life on Earth.
Slime mold might not have evolved much in the past two billion years, but it has learned a few things during that time. In laboratory environments, researchers have cut Physarum polycephalum into pieces and found that it can fuse back together within two minutes. Or, each piece can go off and live separate lives, learn new things, and return later to fuse together, and in the fusing, each individual can teach the other what it knows, and can learn from it in return.
Though, in truth, “individual” is not the right word to use here, because “individuality”—a concept so central to so many humans’ identities—doesn’t apply to the slime mold worldview. A single cell might look to us like a coherent whole, but that cell can divide itself into countless spores, creating countless possible cycles of amoeba to plasmodium to aethalia, which in turn will divide and repeat the cycle again. It can choose to “fruit” or not, to reproduce sexually or asexually or not at all, challenging every traditional concept of “species,” the most basic and fundamental unit of our flawed and imprecise understanding of the biological world. As a consequence, we have no way of knowing whether slime molds, as a broad class of beings, are stable or whether climate change threatens their survival, as it does our own. Without a way to count their population as a species, we can’t measure whether they are endangered or thriving. Should individuals that produce similar fruiting bodies be considered a species? What if two separate slime molds do not mate but share genetic material? The very idea of separateness seems antithetical to slime mold existence. It has so much to teach us…
More at: “What Slime Knows,” from @lacymjohnson in @Orion_Magazine.
See also, “Slime Molds Remember — but Do They Learn?” (from whence the image above) and “Now, in addition to penicillin, we can credit mold with elegant design.”
* Lucretius, On the Nature of Things
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As we contemplate kinship, we might send insightful birthday greetings to Johann Hedwig; he was born on this date in 1730. A botanist noted for his study of mosses, he is considered “the father of bryology” (the study of mosses… cousins of mold).
“Attend to mushrooms and all other things will answer up”*…
The living– and conscious?– infrastructure of the biosphere…
Imagine that you are afloat on your back in the sea. You have some sense of its vast, unknowable depths—worlds of life are surely darting about beneath you. Now imagine lying in a field, or on the forest floor. The same applies, though we rarely think of it: the dirt beneath you, whether a mile or a foot deep, is teeming with more organisms than researchers can quantify. Their best guess is that there are as many as one billion microbes in a single teaspoon of soil. Plant roots plunge and swerve like superhighways with an infinite number of on-ramps. And everywhere there are probing fungi.
Fungi are classified as their own kingdom, separate from plants and animals. They are often microscopic and reside mostly out of sight—mainly underground—but as Merlin Sheldrake writes in Entangled Life: How Fungi Make Our Worlds, Change Our Minds and Shape Our Futures, they support and sustain nearly all living systems. Fungi are nature’s premiere destroyers and creators, digesting the world’s dead and leaving behind new soil. When millions of hair-like fungal threads—called hyphae—coalesce, felting themselves into complex shapes, they emerge from the ground as mushrooms. A mushroom is to a fungus as a pear is to a pear tree: the organism’s fruiting body, with spores instead of seeds. Mushrooms disperse spores by elaborate means: some species generate puffs of air to send them aloft, while others eject them by means of tiny, specialized catapults so they accelerate ten thousand times faster than a space shuttle during launch.
But Sheldrake is most interested in fungi’s other wonders—specifically, how they challenge our understanding of nonhuman intelligence and stretch the notion of biological individuality. Fungi infiltrate the roots of almost every plant, determining so much about its life that researchers are now asking whether plants can be considered plants without them. They are similarly interwoven throughout the human body, busily performing functions necessary to our health and well-being or, depending on the fungi’s species and lifestyle, wreaking havoc. All of this prompts doubts about what we thought we knew to be the boundaries between one organism and another…
ungi themselves form large networks of hyphae strands in order to feed. These strands, when massed together, are called mycelium. The total length of mycelium threaded through the globe’s uppermost four inches of soil is believed to be enough to span half the width of our galaxy. Mycelium is constantly moving, probing its surroundings in every direction and coordinating its movements over long distances. When food is found—a nice chunk of rotting wood, for example—disparate parts of the mycelium redirect to coalesce around it, excrete enzymes that digest it externally, and then absorb it. As Sheldrake puts it, “The difference between animals and fungi is simple: Animals put food in their bodies, whereas fungi put their bodies in the food.”
Fungi are literally woven into the roots and bodies of nearly every plant grown in natural conditions. “A plant’s fungal partners,” Sheldrake writes, “can have a noticeable impact on its growth.” In one striking example, he describes an experiment in which strawberries grown with different fungal partners changed their sweetness and shape. Bumblebees seemed able to discern the difference and were more attracted to the flowers of strawberry plants grown with certain fungal species. Elsewhere he discusses an experiment in which researchers took fungi that inhabited the roots of a species of coastal grass that grew readily in saltwater and added it to a dry-land grass that could not tolerate the sea. Suddenly the dry-land grass did just fine in brine.
Much has been written lately about trees communicating and sharing resources among themselves; healthy trees have been documented moving resources toward trees that have fallen ill. This is often characterized as friendship or altruism between trees, but it is not at all clear whether trees pass information or nutrients intentionally. What is clear, though, is that the fungal networks entwined in every tree root make this communication possible. “Why might it benefit a fungus to pass a warning between the multiple plants that it lives with?” Sheldrake asks. The answer is survival. “If a fungus is connected to several plants and one is attacked by aphids, the fungus will suffer as well as the plant,” he writes. “It is the fungus that stands to benefit from keeping the healthy plant alive.”…
Fungi are genetically closer to animals than to plants, and similar enough to humans at the molecular level that we benefit from many of their biochemical innovations. In fact, many of our pharmaceuticals are borrowed innovations from fungi. Penicillin, discovered in 1928 by the Scottish researcher Alexander Fleming, is a compound produced by fungus for protection against bacterial infection. The anti-cancer drug Taxol was originally isolated from the fungi that live inside yew trees. More than half of all enzymes used in industry are generated by fungi, Sheldrake notes, and 15 percent of all vaccines are produced using yeast. We are, as he puts it, “borrowing a fungal solution and rehousing it within our own bodies.”..
We know that fungi maintain “countless channels of chemical communication with other organisms,” and that they are constantly processing diverse information about their environment. Some can recognize color, thanks to receptors sensitive to blue and red light, though it is not entirely clear what they do with that information. Some even have opsins, light-detecting proteins also found within the rods and cones of the animal eye. One fungus, Phycomyces blakesleeanus, has a sensitivity to light similar to that of a human eye and can “detect light at levels as low as that provided by a single star” to help it decide where to grow. It is also able to sense the presence of nearby objects and will bend away from them before ever making contact. Still other fungi recognize texture; according to Sheldrake, the bean rust fungus has been demonstrated to detect grooves in artificial surfaces “three times shallower than the gap between the laser tracks on a CD.”
Can fungi, then, be said to have a mind of their own? That is, as Sheldrake puts it, a “question of taste”—there is no settled scientific definition for “intelligence,” not even for animals. The Latin root of the word means “to choose between,” an action fungi clearly do all the time. But the application of this kind of term to fungi is loaded with something more mystical than that simple definition and demands a willingness to rattle our sense of where we ourselves fall in the imagined hierarchy of life. If fungi can be said to think, it is a form of cognition so utterly different that we strain to see it.
After all, philosophers of mind like Daniel Dennett argue that drawing any neat line between nonhumans and humans with “real minds” is an “archaic myth.” Our brains evolved from nonmental material. “Brains are just one such network,” Sheldrake writes, “one way of processing information.” We still don’t know how the excitement of brain cells gives rise to experience. Can we really dismiss the possibility of cognition in an organism that clearly adapts, learns, and makes decisions simply based on the lack of a brain structure analogous to ours?
Perhaps there is intelligent life all around us, and our view is too human-centric to notice. Are fungi intelligent? Sheldrake reserves judgment, deferring instead to scientific mystery: “A sophisticated understanding of mycelium is yet to emerge.” Still, after spending long enough in the atmosphere of Sheldrake’s sporulating mind, I began to adopt the fungal perspective. I can’t help now but see something like a mind wherever there might be fungal threads—which is to say everywhere, a mesh-like entangled whole, all over the earth.
Fungi challenge our understanding of nonhuman intelligence and complicate the boundaries between one organism and another: “Our Silent Partners“– Zoë Schlanger (@zoeschlanger) reviewing Merlin Sheldrake’s Entangled Life: How Fungi Make Our Worlds, Change Our Minds and Shape Our Futures in @nybooks.
“Why did the mushroom go to the party? Because he was a fungi.” – Lewis Tomlinson
* A. R. Ammons
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As we ponder partnership, we might spare a thought for Jens Wilhelm August Lind; he died on this date in 1939. An apothecary, botanist and mycologist, he published a full account of all fungi collected in Denmark by his teacher, Emil Rostrup. Combining his pharmaceutical and mycological knowledge, he was early in experimenting with chemical control of plant pathogens.
Lind also collaborated with Knud Jessen on an account on the immigration history of weeds to Denmark.
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