Posts Tagged ‘origin of life’
“There are more things in heaven and Earth, Horatio, than are dreamt of in your philosophy”*…
And some of them were recently found in the woods near Boston…
Researchers have unearthed a trove of wonders in the soil of a Massachusetts forest: an assortment of giant viruses unlike anything scientists had ever seen. The find suggests this group of relatively massive parasites has an even greater ecological diversity and evolutionary importance than researchers knew.
Giant viruses can exceed 2 micrometers in diameter, on par with some bacteria. They can also harbor immense genomes, which reach 2.5 megabases—larger than the genomes of far more complex organisms. Between the discovery of these impressively sized viruses in algae and the culturing of amoeba-infecting Mimiviruses, most of the research on the group has focused on viruses that inhabit freshwater environments. But DNA sequencing has long indicated that giant viruses are diverse and abundant elsewhere, too—especially in sediments and soils, which are estimated to host some 97% of all the viral particles on Earth. Indeed, genomic sequencing of the soils of Harvard Forest—a roughly 16-square-kilometer area west of Boston—indicated the presence of numerous, novel giant viruses.
Now, electron microscopy has allowed scientists to see what others had only sequenced. The diversity of forms was astounding, they report in a bioRxiv preprint. Not only did the researchers see the 20-sided icosahedral shapes they expected, they spotted ones with myriad modifications—tails, altered points, and multilayered or channeled structures abounded. There were even viruses with long tubular appendages, which the team dubbed “Gorgon” morphology [photo above]. Furthermore, many of these putative viral particles were coated with almost hairlike projections, which varied in length, thickness, density, and shape.
The findings suggest virologists have much to discover about how giant viruses interact with their host cells. That likely means the ecological roles these viruses play in soils—and elsewhere they’re found—are woefully underappreciated…
Microbes come in a variety of shapes, hinting at undiscovered ecological diversity: “Alien-looking viruses discovered in Massachusetts forest,” in @ScienceMagazine.
* Shakespeare, Hamlet
As we marvel at multifariousness (and note that viruses, while generally considered to be non-living and thus not considered microorganisms, are colloquially lumped in with microbes), we might spare a thought for Sidney Walter Fox; he died on this date in 1998. A biochemist, he was responsible for a series of discoveries about the origin of life. Fox believed in the process of abiogenesis, by which life spontaneously organized itself from the colloquially known “primordial soup,” poolings of various simple organic molecules that existed during the time before life on Earth. In his experiments (which possessed, he believed, conditions like those of primordial Earth), he demonstrated that it is possible to create protein-like structures from inorganic molecules and thermal energy. Dr. Fox went on to create microspheres that he said closely resembled bacterial cells and concluded that they could be similar to the earliest forms of life or protocells.
“The earth laughs in flowers”*…
The first flower?
With the incredible diversity of flowers that exist today—from pinprick-sized duckweed to the meters-high blooms of a corpse flower—it’s hard to imagine that they all descend from just a single species. Charles Darwin himself wrung his hands over how flowering plants exploded in diversity early in their evolution. Now, researchers have figured out what the ancestral flower might have looked like. The study may help them uncover how flowers took over the world.
Fossils are the surest way to learn about organisms that lived in the past, but these are hard to come by for early flowers: The earliest preserved blossoms date back some 130 million years—at least 10 million years after the time when researchers think the ancestor of all flowering plants was alive. But there is another way to learn about species that are long gone: by taking a careful look at the forms of their modern descendants, and tracing the history of those forms back to the trunk of their family tree.
To that end, dozens of researchers participating in the eFLOWER project amassed data from scientific papers to create the largest database of the structures of modern flowers, like their sexual organs and the layouts of their petals. The analysis included more than 13,000 data points spanning back to a 1783 description by famous evolutionary biologist Jean-Baptiste Lamarck. Combining those data with a DNA-based family tree and information about fossils, the scientists tested millions of configurations of how flowers may have changed through time to determine the most likely structure and shape for the earliest flowers.
Though the team’s reconstructed ancestral flower [pictured above] doesn’t look radically different than many modern flowers, it does have a combination of traits not found today…
Pick (up) the tale in toto at: “The world’s first flower may have looked like this.”
* Ralph Waldo Emerson
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As we cultivate our gardens, we might send fecund birthday greetings to Sidney Walter Fox; he was born on this date in 1912. A biochemist interested in the biological origin of life, he studied the synthesis of amino acids from inorganic molecules. He gave the name proteinoid to the protein-like polymer that results from a mixture of amino acids subjected to such considerable heating as would be present during the volcanic primordial earth (in the “primordial soup” as it’s colloquially known). Fox observed that when proteinoids or “thermal proteins,” are placed in water, they self-organize into microspheres or protocells, possible precursors of the contemporary living cell. Fox argued that RNA or DNA need not date back to the origin of life; and he showed that proteinoid “microspheres,” as he called them, exhibit growth, metabolism, reproduction (by budding), and responsiveness to stimuli – all properties of life – though without a genetic system.
“All of today’s DNA, strung through all the cells of the earth, is simply an extension and elaboration of [the] first molecule”*…
The first biological teleporter sits in a lab on the lower level of the San Diego building that houses Synthetic Genomics Inc. (SGI), looking something like a super-sized equipment cart.
The device is actually conglomeration of small machines and lab robots, linked to each other to form one big machine. But this one can do something unprecedented: it can use transmitted digital code to print viruses.
In a series of experiments culminating last year, SGI scientists used genetic instructions sent to the device from elsewhere in the building to automatically manufacture the DNA of the common flu virus. They also produced a functional bacteriophage, a virus that infects bacterial cells.
Although that wasn’t the first time anyone had made a virus from DNA parts, it was the first time it was done automatically, without human hands.
The device, called a “digital-to-biological converter” was unveiled in May. Though still a prototype, instruments like it could one day broadcast biological information from sites of a disease outbreak to vaccine manufacturers, or print out on-demand personalized medicines at patients’ bedsides…
… or project life-as-we-know it into outer space. More at “Biological Teleporter Could Seed Life Through Galaxy.”
* Lewis Thomas, The Medusa and the Snail
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As we beam up, we might spare a thought for Sidney Walter Fox; he died on this date in 1998. A biochemist, he was responsible for a series of discoveries about the origin of life. Fox believed in the process of abiogenesis, by which life spontaneously organized itself from the colloquially known “primordial soup,” poolings of various simple organic molecules that existed during the time before life on Earth. In his experiments (which possessed, he believed, conditions like those of primordial Earth), he demonstrated that it is possible to create protein-like structures from inorganic molecules and thermal energy. Dr. Fox went on to create microspheres that he said closely resembled bacterial cells and concluded that they could be similar to the earliest forms of life or protocells.
“To imagine a language is to imagine a form of life”*…
Jeremy England is concerned about words—about what they mean, about the universes they contain. He avoids ones like “consciousness” and “information”; too loaded, he says. Too treacherous. When he’s searching for the right thing to say, his voice breaks a little, scattering across an octave or two before resuming a fluid sonority.
His caution is understandable. The 34-year-old assistant professor of physics at the Massachusetts Institute of Technology is the architect of a new theory called “dissipative adaptation,” which has helped to explain how complex, life-like function can self-organize and emerge from simpler things, including inanimate matter. This proposition has earned England a somewhat unwelcome nickname: the next Charles Darwin. But England’s story is just as much about language as it is about biology…
A new theory on the emergence of life’s complexity: “How Do You Say ‘Life’ in Physics?“
* Ludwig Wittgenstein, Philosophical Investigations
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As we resist the urge to simplify, we might send carefully-constructed birthday greetings to Sir Karl Raimund Popper; he was born on this date in 1902. One of the greatest philosophers of science of the 20th century, Popper is best known for his rejection of the classical inductivist views on the scientific method, in favor of empirical falsification: A theory in the empirical sciences can never be proven, but it can be falsified, meaning that it can and should be scrutinized by decisive experiments. (Or more simply put, whereas classical inductive approaches considered hypotheses false until proven true, Popper reversed the logic: conclusions drawn from an empirical finding are true until proven false.)
Popper was also a powerful critic of historicism in political thought, and (in books like The Open Society and Its Enemies and The Poverty of Historicism) an enemy of authoritarianism and totalitarianism.
Grandad?!?!?…
Humankind’s remotest relative is a very rare micro-organism from south-Norway. The discovery may provide an insight into what life looked like on earth almost one thousand million years ago… “We have found an unknown branch of the tree of life that lives in this lake. It is unique! So far we know of no other group of organisms that descend from closer to the roots of the tree of life than this species. It can be used as a telescope into the primordial micro-cosmos,” says an enthusiastic associate professor, Kamran Shalchian-Tabrizi, head of the Microbial Evolution Research Group (MERG) at the University of Oslo…
Life on Earth can be divided up into two main groups of species, prokaryotes and eukaryotes. The prokaryote species, such as bacteria, are the simplest form of living organisms on Earth. They have no membrane inside their cell and therefore no real cell nucleus. Eukaryote species, such as animals and humankind, plants, fungi and algae, on the other hand do.
The family tree of the protozoan from the lake starts at the root of the eukaryote species.
“The micro-organism is among the oldest, currently living eukaryote organisms we know of. It evolved around one billion years ago, plus or minus a few hundred million years. It gives us a better understanding of what early life on Earth looked like,” Kamran says…
More– including how newly-developed techniques in genetic analysis enabled the “decoding” of the organism, first discovered in the mis-Nineteenth Century, and how the protozoa might be useful in purifying drinking water– in this article in Science Daily.
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As we marvel at the miracle of mutation, we might recall that it was on this date in 1887 that “Buffalo Bill’s Wild West Show,” including “the selected representatives of several nations, including the Sioux, the Cheyennes, and the Pawnees,” sharpshooter Annie Oakley, and Colonel William F Cody– Buffalo Bill– himself, opened in London. As The (London) Times reported:
Its great object is to illustrate the wild life of the Western frontier–its Indians and cowboys, its buffalo-huntings and cattle-ranches, its pioneering and its horsemanship, its dangers and its joys.
And so, for nearly a year, it did.
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