Posts Tagged ‘zoology’
“Nature uses only the longest threads to weave her patterns, so that each small piece of her fabric reveals the organization of the entire tapestry”*…
More than 70 years ago, mathematician Alan Turing proposed a mechanism that explained how patterns could emerge from bland uniformity. As Amber Dance explains, scientists are still using his model — and adding new twists — to gain a deeper understanding of animal markings…
There’s a reason fashion designers look to animal prints for inspiration. Creatures have evolved a dizzying array of patterns: stripes, spots, diamonds, chevrons, hexagons and even mazelike designs. Some, like peacocks, want to be seen, to attract a mate or scare off a rival or predator. Others, like tigers or female ducks, need to blend in, either to sneak up on prey or to avoid becoming lunch themselves.
Some patterns arise simply or randomly, but others develop via complex, precise interactions of pattern-generating systems. Their beauty aside, the intricacies of these systems are inspiring the scientists who aim to elucidate how the tiger got its stripes, the cheetah its spots and more besides.
Mammals like cats and dogs can have white tummies. They get them in a straightforward way: As the embryo develops, pigment-making cells originate along the site of the future spine and migrate down and around toward the belly. But sometimes they don’t make it all the way. Where the pigment cells run out of steam, the white begins.
The black dots on Dalmatians are generated randomly. So are the black-and-orange splotches on calico cats.
But the stripes of chipmunks and tigers, the speckles on fishes and chickens, and many other glorious animal features are laid down with exquisite precision. In a remarkable feat of self-organization, a uniform surface becomes patterned.
The person who figured out how this happens was Alan Turing [here]. You may know him as the 20th century mathematician who broke Nazi codes during World War II and developed early concepts in artificial intelligence.Turing also turned his math skills to understanding how regular features could emerge on the developing embryo. Scientists since then have applied his equations to the development of such patterns as fingerprint ridges, the places where hairs will sprout, and color patterns like stripes and spots.And it turns out he was really onto something: Today, scientists studying animal patterns still find Turing’s ideas to be remarkably effective — especially when combined with other factors that elaborate the patterns further….
A colorful tour of what scientists are learning today, starting with Turing’s theory: “Spots, stripes and more: Working out the logic of animal patterns,” from @amberldance in @KnowableMag.
* Richard Feynman
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As we contemplate coloring, we might spare a thought for Emanuel Mendes da Costa; he died on this date in 1791. A naturalist, he published A Natural History of Fossils in 1757 and served as clerk (from 1763) to the Royal Society– from which he embezzled membership funds to indulge his reckless penchant for collecting. When caught in 1767, the treasury was short by £1500—a substantial amount in those years. He confessed; his collections were auctioned to make restitution; but he was still sentenced for five years to debtor’s prison. After release he scraped by, with lecturing about fossils, translating, and trading in mineral, fossil and shell specimens. He wrote two books on shells and was perhaps the first to coin the word conchology. Still impoverished, he died in penury.
“The conundrum of free will and destiny has always kept me dangling”*…
… as it’s kept thinkers dangling for centuries. Dan Falk considers two new books– one arguing that free will is an illusion; the other, that free will is the (very real) result of evolution…
You’re thirsty so you reach for a glass of water. It’s either a freely chosen action or the inevitable result of the laws of nature, depending on who you ask. Do we have free will? The question is ancient—and vexing. Everyone seems to have pondered it, and many seem quite certain of the answer, which is typically either “yes” or “absolutely not.”
One scientist in the “absolutely not” camp is Robert Sapolsky. In his new book, Determined: A Science of Life Without Free Will, the primatologist and Stanford professor of neurology spells out why we can’t possibly have free will. Why do we behave one way and not another? Why do we choose Brand A over Brand B, or vote for Candidate X over Candidate Y? Not because we have free will, but because every act and thought are the product of “cumulative biological and environmental luck.”
Sapolsky tells readers that the “biology over which you had no control, interacting with the environment over which you had no control, made you you.” That is to say, “everything in your childhood, starting with how you were mothered within minutes of birth, was influenced by culture, which means as well by the centuries of ecological factors that influenced what kind of culture your ancestors invented, and by the evolutionary pressures that molded the species you belong to.”
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Many scientists and philosophers beg to differ. Prominent among them is Kevin Mitchell, a neuroscientist at Trinity College in Dublin. In his new book, Free Agents: How Evolution Gave Us Free Will, Mitchell argues that although we’re shaped by our biology, it’s that very biology that made us, over the course of billions of years of evolution, into free agents. Even the earliest and most primitive creatures had some capacity to control their destinies. When a single-celled organism moves toward a food source, or away from danger, it has entered, however meekly, into a new world of agency and freedom. Simple organisms, Mitchell writes, “infer what is out in the world” and “make holistic decisions to adapt their internal dynamics and select appropriate actions.” He adds: “This represents a wholly different type of causation from anything seen before in the universe.”…
n a universe where the mindless laws of nature push bits of matter around, it might indeed seem miraculous that free will—agency—can emerge. As I made my way through Free Agents, I thought of a New Yorker cartoon where two scientists are at a blackboard filled with equations. In the middle, instead of an equation, the first scientist has written, “Then a miracle occurs.” The second guy says to him, “I think you should be more explicit here in step two.”
But emerge it does, according to Mitchell, and he’s adamant that there is nothing miraculous about it. Rather, in living creatures like us, freedom is enabled by the underlying biology…
Yes, there are physical and chemical processes operating within the brain—how could there not be?—but that does nothing to take away our freedom, he says. “It comes down to the idea that if we can find the machinery inside the brain that is active when we’re making a decision, then maybe decision making just is being done causally by that machinery,” he told me. “I don’t think that view is right, because I think you can have a completely different view, which is, yes, there is some machinery that we use to make decisions; but it’s machinery we use to make decisions. We’re making the decisions.”
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A fascinating look at a volley of new insights that has reignited the debate over whether our choices are ever truly our own: “Yes, We Have Free Will. No, We Absolutely Do Not,” from @danfalk in @NautilusMag.
As Eistein observed, “I am a determinist. As such, I do not believe in free will…Practically, I am, nevertheless, compelled to act as if freedom of the will existed. If I wish to live in a civilized community, I must act as if man is a responsible being.
To which Stephen Hawking added: “I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.”
* that well-known philosopher, William Shatner
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As we muse on motive, we might send categorical birthday greetings to Konrad Zacharias Lorenz; he was born on this date in 1903. A zoologist and ornithologist, he founded the modern field of ethology. His work– popularized in books like King Solomon’s Ring, On Aggression, and Man Meets Dog– revealed how behavioral patterns may be traced to an evolutionary past and explored the roots of aggression. He shared the 1973 Nobel Prize for Physiology and Medicine for developing a unified, evolutionary theory of animal and human behavior… which was, overall, determinist.
“The Quaker loves an ample brim, / A hat that bows to no salaam; / And dear the beaver is to him / As if it never made a dam”*…
Leila Philip on the evolutionary puzzles and unfathomable intelligence of earth’s rodent-engineers…
I think there is an element of the sacred in the beaver, if only in its deep weirdness. One million years ago, beavers the size of bears roamed North America. They pose an evolutionary puzzle, like the platypus, or birds, which share some DNA with dinosaurs. When they dive, they seem more like marine mammals than terrestrial species, more seal than rodent. Their dexterous forepaws look startlingly human with their five nimble fingers and naked palms. They groom their lustrous fur with catlike fastidiousness. Their mammalian beauty ends abruptly in the gooselike hind feet, each as wide as the beaver’s head. The feet are followed by a reptilian tail, which, it has been observed, looks like the result of some terrible accident, run over by a tractor tire, the treads leaving a pattern of indentations that resemble scales.
Part bear, part bird, part monkey, part lizard, humanoid hands, an aquatic tail. Is it any surprise that beavers have fired the human imagination in every continent that they are found?…
“Part Bear, Part Bird, Part Monkey, Part Lizard: On the Deep Weirdness of Beavers,” from @theleilaphilip in @lithub.
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As we get busy, we might recall that it was on this date in 1928 that former concert violinist and proprietor of the One-In-Hand Tie Company of Clinton, Iowa, Joseph W. Less, introduced the modern clip-on tie.
“Every decently-made object… is not just a piece of ‘stuff’ but a physical embodiment of human energy, testimony to the magical ability of our species to take raw materials and turn them into things of use, value and beauty”*…
Indeed, as the Materials Library of the Institute for Making at UCL brilliantly demonstrates, that’s often true of the materials themselves…
The Materials Library is a collection of some of the most wondrous materials on earth, gathered from sheds, labs, grottoes and repositories around the world. It is a resource, laboratory, studio, and playground for the curious and material-minded to conduct hands-on research through truly interdisciplinary inquiry and innovation. The collection is accessible to Institute of Making members day to day, and to the public at Materials Library Discovery sessions.
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As we celebrate stuff, we might spare a thought for Addison Emery Verrill; he died on this date in 1926. An invertebrate zoologist, museum curator, and university professor, he is best remembered as curator of zoology at the Peabody Museum of Natural History at Yale University, where he developed one of the largest, most valuable zoological collections in the U.S.
Verill trained under Louis Agassiz at Harvard; then, at age 25, became Yale University’s first professor of Zoology. His lifelong devotion to taxonomic research yielded the development of extensive collections at Yale in a wide variety of taxa. From 1871-87, while he was in charge of scientific explorations by the U.S. Commission of Fish and Fisheries, Verrill found and described hundreds of new marine specimens. His expeditions took him to the Atlantic and Pacific coasts of North America and to Hawaii and Central America. He published more than 350 papers and monographs, including descriptions of more than a thousand species of animals in virtually every major taxon. His breadth of interests included parasitology, mineralogy and botany.
“What is the pattern that connects the crab to the lobster and the primrose to the orchid, and all of them to me, and me to you?”*…
Crab-like body plans have evolved independently at least five times. As Jason P. Dihn explains, biologists are still trying to figure out exactly why…
In 1989, paleontologist Stephen Jay Gould proposed a thought experiment: What would the world look like if we turned back time and replayed the evolutionary tape? “I doubt that anything like Homo sapiens would ever evolve again,” he concluded. Maybe not. But crabs might.
Evolution just can’t stop creating crabs. Believe it or not, the flat-and-wide body plan has evolved at least five different times. The process is called carcinization, and it’s inspired comics, memes and entire subreddits.
Still, biologists don’t know why crabs keep evolving. Figuring it out would satisfy the online masses, sure, but it would also be a step toward solving other important scientific mysteries. For instance, why some species share evolutionary paths while others forge unique ones (looking at you, platypus)…
Convergent evolution: “Evolution Only Thinks About One Thing, and It’s Crabs,” from @JasonPDinh in @DiscoverMag.
Will crabs need to (re-)evolve a sixth time? “Alaska’s snow crabs have disappeared. Where they went is a mystery.”
(Image above: source)
* Gregory Bateson
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As we fiddle with phylogeny, we might spare a thought for Walter Rothschild, 2nd Baron Rothschild; he died on this date in 1937. A British banker, politician and soldier, he is best remembered for his pursuit of his passion— zoology and his collection of species. At its largest, Rothschild’s collection included 300,000 bird skins, 200,000 birds’ eggs, 2,250,000 butterflies and 30,000 beetles, as well as thousands of specimens of mammals, reptiles, and fishes. They formed the largest zoological collection ever amassed by a private individual (and are now part of the Natural History Museum). He named dozens of animal taxa, published Novitates Zoologicae, and authored or co-authored scores of scientific papers.
Related: “How Bird Collecting Evolved Into Bird-Watching.”
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