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Posts Tagged ‘biology

“Over the long term, symbiosis is more useful than parasitism. More fun, too.”*…

Blue-green formations of malachite form in copper deposits near the surface as they weather. But they could only arise after life raised atmospheric oxygen levels, starting about 2.5 billion years ago.

There are many more varieties of minerals on earth than previously believed– and about half of them formed as parts or byproducts of living things…

The impact of Earth’s geology on life is easy to see, with organisms adapting to environments as different as deserts, mountains, forests, and oceans. The full impact of life on geology, however, can be easy to miss.

A comprehensive new survey of our planet’s minerals now corrects that omission. Among its findings is evidence that about half of all mineral diversity is the direct or indirect result of living things and their byproducts. It’s a discovery that could provide valuable insights to scientists piecing together Earth’s complex geological history—and also to those searching for evidence of life beyond this world.

In a pair of papers published on July 1, 2022 in American Mineralogist, researchers Robert HazenShaunna Morrison and their collaborators outline a new taxonomic system for classifying minerals, one that places importance on precisely how minerals form, not just how they look. In so doing, their system acknowledges how Earth’s geological development and the evolution of life influence each other.

Their new taxonomy, based on an algorithmic analysis of thousands of scientific papers, recognizes more than 10,500 different types of minerals. That’s almost twice as many as the roughly 5,800 mineral “species” in the classic taxonomy of the International Mineralogical Association, which focuses strictly on a mineral’s crystalline structure and chemical makeup.

Morrison and Hazen also identified 57 processes that individually or in combination created all known minerals. These processes included various types of weathering, chemical precipitations, metamorphic transformation inside the mantle, lightning strikes, radiation, oxidation, massive impacts during Earth’s formation, and even condensations in interstellar space before the planet formed. They confirmed that the biggest single factor in mineral diversity on Earth is water, which through a variety of chemical and physical processes helps to generate more than 80 percent of minerals.

But they also found that life is a key player: One-third of all mineral kinds form exclusively as parts or byproducts of living things—such as bits of bones, teeth, coral, and kidney stones (which are all rich in mineral content) or feces, wood, microbial mats, and other organic materials that over geologic time can absorb elements from their surroundings and transform into something more like rock. Thousands of minerals are shaped by life’s activity in other ways, such as germanium compounds that form in industrial coal fires. Including substances created through interactions with byproducts of life, such as the oxygen produced in photosynthesis, life’s fingerprints are on about half of all minerals.

But they also found that life is a key player: One-third of all mineral kinds form exclusively as parts or byproducts of living things—such as bits of bones, teeth, coral, and kidney stones (which are all rich in mineral content) or feces, wood, microbial mats, and other organic materials that over geologic time can absorb elements from their surroundings and transform into something more like rock. Thousands of minerals are shaped by life’s activity in other ways, such as germanium compounds that form in industrial coal fires. Including substances created through interactions with byproducts of life, such as the oxygen produced in photosynthesis, life’s fingerprints are on about half of all minerals.

Historically, scientists “have artificially drawn a line between what is geochemistry and what is biochemistry,” said Nita Sahai, a biomineralization specialist at the University of Akron in Ohio who was not involved in the new research. In reality, the boundary between animal, vegetable, and mineral is much more fluid.

A new origins-based system for classifying minerals reveals the huge geochemical imprint that life has left on Earth. It could help us identify other worlds with life too: “Life Helps Make Almost Half of All Minerals on Earth,” from @jojofoshosho0 in @QuantaMagazine.

Larry Wall

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As we muse on minerals, we might send systemic birthday greetings to Thomas Samuel Kuhn; he was born on this date in 1922.  A physicist, historian, and philosopher of science, Kuhn believed that scientific knowledge didn’t advance in a linear, continuous way, but via periodic “paradigm shifts.”  Karl Popper had approached the same territory in his development of the principle of “falsification” (to paraphrase, a theory isn’t false until it’s proven true; it’s true until it’s proven false).  But while Popper worked as a logician, Kuhn worked as a historian.  His 1962 book The Structure of Scientific Revolutions made his case; and while he had– and has— his detractors, Kuhn’s work has been deeply influential in both academic and popular circles (indeed, the phrase “paradigm shift” has become an English-language staple).

“What man sees depends both upon what he looks at and also upon what his previous visual-conception experience has taught him to see.”

Thomas S. Kuhn, The Structure of Scientific Revolutions

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“What’s in a name?”*…

“Copi” (nee Carp)

How to rid the Midwest of an invasive aquatic species? As Sarah Kuta explains, the State of Illinois hopes that it can convince its citizens to help…

For decades, invasive species of carp have been wreaking havoc on lakes and waterways in the American Midwest. One way to help tackle the infestation is simply to catch, cook and eat the fish, but many diners turn up their noses when they hear the word carp.

Now, the Illinois Department of Natural Resources and other partners hope that giving the fish a fresh new image will make them more appealing to eat. They’ve given the invasive species a new name, “copi,” in hopes that people will order copi dishes at restaurants or even cook up the fish at home.

… carp began to spread widely when the other four carp species were imported to the United States in the 1960s and ‘70s to eat algae in wastewater treatment plants and aquaculture ponds, as well as to serve as a source of food.

The fish escaped into the Mississippi River, then continued their spread into other rivers and beyond. Their population grew quickly, and they began to crowd out native fish species, outcompeting them for food (different carp species feed on plants, plankton, on up in size to endangered freshwater snail species). Invasive carp are also thought to lower water quality, which ultimately harms underwater ecosystems and can kill off other native species like freshwater mussels. (The fish were once collectively called “Asian carp,” but state governments and federal agencies now refer to them as “invasive carp” because of concerns over bigotry toward Asian culture and people.)

Federal, state and local officials have since spent hundreds of millions of dollars trying to keep the invasive fish in check, and most importantly, out of the Great Lakes. If the fish swim into Lake Michigan, they could threaten the commercial fishing and tourism industries, which together are responsible for billions of dollars of economic activity…

The new name comes from the word “copious,” a nod to the sheer abundance of these fish…

From the Annals of Marketing: “Can Rebranding Invasive Carp Make It More Appealing to Eat?,” from @SarahKuta in @SmithsonianMag.

* Shakespeare, Romeo and Juliet

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As we dig in, we might recall that on this date in 1862 (88 years after the Declaration of Independence was adopted by the Second Continental Congress on this same date), Charles Lutwidge Dodgson, a young Oxford mathematics don, took the daughters of the Dean of Christ Church College– Alice Liddell and her sisters– on a boating picnic on the River Thames in Oxford.  To amuse the children he told them the story of a little girl, bored by a riverbank, whose adventure begins when she tumbles down a rabbit hole into a topsy-turvy world called “Wonderland.”  The story so captivated the 10-year-old Alice that she begged him to write it down. The result was Alice’s Adventures in Wonderland, published in 1865 under the pen name “Lewis Carroll,” with illustrations by John Tenniel.

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“Sharks. I never saw that coming.”*…

While many land-based predators (like wolves) avoid cities, scientists tracking sharks in Florida’s Biscayne Bay found the fish spent just as much time near Miami as away from it. Warren Cornwall explains…

Certain kinds of wildlife are notorious for thriving in urban settings. Think rats, rock pigeons and even the occasional coyote. Now, Florida scientists have added another creature to the list: sharks.

While many large predators show little appetite for city living, an intriguing project tracking the movements of sharks as fearsome as hammerheads revealed the fish are unexpectedly tolerant of life up close to the 6 million humans of greater Miami.

“We were surprised to find that the sharks we tracked spent so much time near the lights and sounds of the busy city, often close to shore, no matter the time of day,” said Neil Hammerschlag, director of the University of Miami’s Shark Research and Conservation Program.

Ecologists group animals into two main categories when it comes to their tolerance for human development. Some, like raccoons or rats, have figured out how to capitalize on the trash we make and the nooks and crannies we build. They are “urban exploiters.” Then there are the animals like mountain lions, lynxes and wolves that generally give human infrastructure a wide berth, often abandoning habitat where roads or buildings encroach. These are the “urban avoiders.”

As that list suggests, on land, big, toothy predators generally keep their distance from the din of the city. But less is known about their aquatic counterparts. So, a group of researchers set out to see if the sharks of Miami’s Biscayne Bay might shed some light on the matter…

The new wildlife in town: Sharks,” from @WarrenCornwall in @AnthropoceneMag.

Sharknado

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As we hug the shore, we might send deep birthday greetings to Robert Ballard; he was born on this date in 1942. An oceanographer, explorer, retired naval officer, and professor, he noted for his work in underwater archaeology: maritime archaeology and archaeology of shipwrecks. He is probably best known for his discoveries of the wrecks of the RMS Titanic in 1985, the battleship Bismarck in 1989, the aircraft carrier USS Yorktown in 1998, and the wreck of John F. Kennedy’s PT-109 in 2002. But he believes that his most important discovery was the existence of hydrothermal vents.

Ballard at TED, 2008

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“Plants can’t move, yet the insects come to them and spread their pollen”*…

A canola plant damaged by heat and drought in Saskatchewan, Canada last July

The impact of climate change on agriculture is much discussed– but mostly at the level of yields. Carolyn Beans looks into what a warming planet means for fertilization and reproduction…

… heat is a pollen killer. Even with adequate water, heat can damage pollen and prevent fertilization in canola and many other crops, including corn, peanuts, and rice.

For this reason, many growers aim for crops to bloom before the temperature rises. But as climate change increases the number of days over 90 degrees in regions across the globe, and multi-day stretches of extreme heat become more common, getting that timing right could become challenging, if not impossible.

Faced with a warmer future, researchers are searching for ways to help pollen beat the heat. They’re uncovering genes that could lead to more heat-tolerant varieties and breeding cultivars that can survive winter and flower before heat strikes. They’re probing pollen’s precise limits and even harvesting pollen at large scales to spray directly onto crops when weather improves.

At stake is much of our diet. Every seed, grain, and fruit that we eat is a direct product of pollination…

Farmers and scientists are increasingly observing that unusually high springtime temperatures can kill pollen and interfere with the fertilization of crops. Researchers are now searching for ways to help pollen beat the heat, including developing more heat-tolerant varieties: “Pollen and Heat: A Looming Challenge for Global Agriculture,” from @carolynmbeans in @YaleE360.

* Nahoko Uehashi

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As we try to stay cool, we might recall that it was on this date in 1960 that chlorophyll– the green pigment responsible for photosynthesis in plants– was first synthesized. The feat was accomplished by Robert Burns Woodward, the preeminent synthetic organic chemist of the twentieth century, who was awarded the Nobel Prize in 1965 for this and other syntheses of complex natural compounds (including Vitamin b12).

Robert Burns Woodward

“Homo sapiens, the only creature endowed with reason, is also the only creature to pin its existence on things unreasonable”*…

We appeared 800,000-300,000 years ago, or in the last 1.5%-5.3% of hominid history

How, Sarah Constantin asks, did we humans get so smart?

If you zoom way out and look at the history of life on Earth, humans evolved incredibly recently. The Hominidae — the family that includes orangutans, chimpanzees, bonobos, gorillas, and humans — only arose 20 million years ago, in the most recent 0.5% of evolutionary history.

Within the Hominidae, in turn, Homo sapiens is a very recent development [see image at top]. We appeared 800,000-300,000 years ago, or in the last 1.5%-5.3% of hominid history.

If you look at early hominid “technological” milestones like tool use or cooking, though, they’re a lot more spread out over time. That’s interesting.

There’s nothing to suggest that a single physical change in brains should have given us both tool use and fire, for instance; if that were the case, you’d expect to see them show up at the same time.

Purposeful problem-solving behaviors like tool use and cooking are not unique to hominids; some other mammals and birds use tools, and lots of vertebrates (including birds and fish) can learn to solve puzzles to get a food reward. The general class of “problem-solving behavior” that we see, to one degree or another, in many vertebrates, doesn’t seem to have arisen surprisingly fast compared to the existence of animals in general.

However, to the extent that Homo sapiens has unique cognitive abilities, those did show up surprisingly recently, and it makes sense to privilege the hypothesis that they have a common physical cause.

So what are these special human-unique cognitive abilities?…

Is Human Intelligence Simple? Part 1: Evolution and Archaeology,” from @s_r_constantin. Part 2 is here.

* Henri Bergson

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As we study our species, we might send self-examining birthday greetings to Giambattista Vico; he was born on this date in 1668.  A political philosopher, rhetorician, historian, and jurist, Vico was one of the greatest Enlightenment thinkers.  Best known for the Scienza Nuova (1725, often published in English as New Science), he famously criticized the expansion and development of modern rationalism and was an apologist for classical antiquity.

He was an important precursor of systemic and complexity thinking (as opposed to Cartesian analysis and other kinds of reductionism); and he can be credited with the first exposition of the fundamental aspects of social science (and so, is considered by many to be the first forerunner of cultural anthropology and ethnography), though his views did not necessarily influence the first social scientists.  Vico is often claimed to have fathered modern philosophy of history (although the term is not found in his text; Vico speaks of a “history of philosophy narrated philosophically’).  While he was not strictly speaking a historicist, interest in him has been driven by historicists (like Isaiah Berlin).

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