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Archive for the ‘evolution’ category

Mar 28, 2020

From Bats to Human Lungs, the Evolution of a Coronavirus

Posted by in categories: biotech/medical, evolution, genetics

There are endless viruses in our midst, made either of RNA or DNA viruses, which exist in much greater abundance around the planet, are capable of causing systemic diseases that are endemic, latent, and persistent—like the herpes viruses (which includes chicken pox), hepatitis B, and the papilloma viruses that cause cancer. “DNA viruses are the ones that live with us and stay with us,” Denison said. “They’re lifelong.” Retroviruses, like H.I.V., have RNA in their genomes but behave like DNA viruses in the host. RNA viruses, on the other hand, have simpler structures and mutate rapidly. “Viruses mutate quickly, and they can retain advantageous traits,” Epstein told me. “A virus that’s more promiscuous, more generalist, that can inhabit and propagate in lots of other hosts ultimately has a better chance of surviving.” They also tend to cause epidemics—such as measles, Ebola, Zika, and a raft of respiratory infections, including influenza and coronaviruses. Paul Turner, a Rachel Carson professor of ecology and evolutionary biology at Yale University, told me, “They’re the ones that surprise us the most and do the most damage.”

Scientists discovered the coronavirus family in the nineteen-fifties, while peering through early electron microscopes at samples taken from chickens suffering from infectious bronchitis. The coronavirus’s RNA, its genetic code, is swathed in three different kinds of proteins, one of which decorates the virus’s surface with mushroom-like spikes, giving the virus the eponymous appearance of a crown. Scientists found other coronaviruses that caused disease in pigs and cows, and then, in the mid-nineteen-sixties, two more that caused a common cold in people. (Later, widespread screening identified two more human coronaviruses, responsible for colds.) These four common-cold viruses might have come, long ago, from animals, but they are now entirely human viruses, responsible for fifteen to thirty per cent of the seasonal colds in a given year. We are their natural reservoir, just as bats are the natural reservoir for hundreds of other coronaviruses. But, since they did not seem to cause severe disease, they were mostly ignored. In 2003, a conference for nidovirales (the taxonomic order under which coronaviruses fall) was nearly cancelled, due to lack of interest. Then SARS emerged, leaping from bats to civets to people. The conference sold out.

SARS is closely related to the new virus we currently face. Whereas common-cold coronaviruses tend to infect only the upper respiratory tract (mainly the nose and throat), making them highly contagious, SARS primarily infects the lower respiratory system (the lungs), and therefore causes a much more lethal disease, with a fatality rate of approximately ten per cent. (MERS, which emerged in Saudi Arabia, in 2012, and was transmitted from bats to camels to people, also caused severe disease in the lower respiratory system, with a thirty-seven per cent fatality rate.) SARS-CoV-2 behaves like a monstrous mutant hybrid of all the human coronaviruses that came before it. It can infect and replicate throughout our airways. “That’s why it is so bad,” Stanley Perlman, a professor of microbiology and immunology who has been studying coronaviruses for more than three decades, told me. “It has the lower-respiratory severity of SARS and MERS coronaviruses, and the transmissibility of cold coronaviruses.”

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Mar 23, 2020

Secret of the ‘immortal’ hydra’s regenerating ability uncovered

Posted by in categories: evolution, life extension, neuroscience

The hydra is named after the serpent monster from Greek myth, which regrows two heads each time one is cut off. But freshwater hydras have an even more impressive regenerating ability: an entire hydra can regrow from a small piece of tissue in only a few days.

Biologists are particularly excited by this ability, since many of the networks involved in the healing process developed early in the process of evolution, meaning that they are shared among many animals, including humans.

“In other organisms, like humans, once our brain is injured, we have difficulty recovering because the brain lacks the kind of regenerative abilities we see in hydra,” said researcher Abby Primack.

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Mar 21, 2020

The new coronavirus was not genetically engineered, study shows

Posted by in categories: bioengineering, biotech/medical, evolution, genetics

Josie Golding, Ph.D., who is the epidemics lead at the Wellcome Trust, a research charity based in London, United Kingdom, did not participate in the study but comments on its significance.

She says the findings are “crucially important to bring an evidence-based view to the rumors that have been circulating about the origins of the virus (SARS-CoV-2) causing COVID-19.”

“[The authors] conclude that the virus is the product of natural evolution,” Goulding adds, “ending any speculation about deliberate genetic engineering.”

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Mar 19, 2020

COVID-19 coronavirus epidemic has a natural origin

Posted by in categories: bioengineering, biotech/medical, evolution

I know some have speculated that the Coronavirus was engineered:

An analysis of public genome sequence data from SARS-CoV-2 and related viruses found no evidence that the virus was made in a laboratory or otherwise engineered.


The novel SARS-CoV-2 coronavirus that emerged in the city of Wuhan, China, last year and has since caused a large scale COVID-19 epidemic and spread to more than 70 other countries is the product of natural evolution, according to findings published today in the journal Nature Medicine.

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Mar 19, 2020

Astronomers determine chemical composition of a nearby stellar stream

Posted by in categories: evolution, space

Stellar streams are long, thin filaments of orbiting galaxies, produced by the stretching action of tidal forces. For astronomers, observation of these structures could be crucial to test various galaxy formation models.

Located most likely some 420 light-years away in the Milky Way’s disk, Pisces–Eridanus (or Psc–Eri for short) is a cylindrically shaped stream of almost 1,400 identified stars distributed across about 2,300 light-years. Due to its relative proximity and , it is perceived as an excellent laboratory to study and test theories of chemical and dynamical evolution of stellar systems.

Mar 18, 2020

Ancient fish fossil reveals evolutionary origin of the human hand

Posted by in categories: evolution, habitats

An ancient Elpistostege fish fossil found in Miguasha, Canada has revealed new insights into how the human hand evolved from fish fins.

An international team of palaeontologists from Flinders University in Australia and Universite du Quebec a Rimouski in Canada have revealed the specimen, as described in the journal Nature, has yielded the missing evolutionary link in the fish to tetrapod transition, as fish began to foray in habitats such as and land during the Late Devonian period millions of years ago.

This complete 1.57 metre long fish shows the complete arm (pectoral fin) skeleton for the first time in any elpistostegalian fish. Using high energy CT-scans, the skeleton of the pectoral fin revealed the presence of a humerus (arm), radius and ulna (forearm), rows of carpus (wrist) and phalanges organized in digits (fingers).

Mar 16, 2020

Scientists have discovered the origins of the building blocks of life

Posted by in categories: alien life, evolution

:oooooo.


Rutgers researchers have discovered the origins of the protein structures responsible for metabolism: simple molecules that powered early life on Earth and serve as chemical signals that NASA could use to search for life on other planets.

Their study, which predicts what the earliest proteins looked like 3.5 billion to 2.5 billion years ago, is published in the journal Proceedings of the National Academy of Sciences.

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Mar 13, 2020

Slime Mold Simulations Map Dark Matter Holding Universe Together

Posted by in categories: biological, cosmology, evolution

The behavior of one of nature’s humblest creatures is helping astronomers probe the largest structures in the universe.

The single-cell organism, known as slime mold (Physarum polycephalum), builds complex filamentary networks in search of food, finding near-optimal pathways to connect different locations. In shaping the universe, gravity builds a vast cobweb structure of filaments tying galaxies and clusters of galaxies together along faint bridges hundreds of millions of light-years long. There is an uncanny resemblance between the two networks: one crafted by biological evolution, and the other by the primordial force of gravity.

The cosmic web is the large-scale backbone of the cosmos, consisting primarily of the mysterious substance known as dark matter and laced with gas, upon which galaxies are built. Dark matter cannot be seen, but it makes up the bulk of the universe’s material. The existence of a web-like structure to the universe was first hinted at in the 1985 Redshift Survey conducted at the Harvard-Smithsonian Center for Astrophysics. Since those studies, the grand scale of this filamentary structure has grown in subsequent sky surveys. The filaments form the boundaries between large voids in the universe.

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Mar 9, 2020

CRISPR Pill May Be Key in Fight Against Antibiotic Resistance

Posted by in categories: biotech/medical, evolution

Even since Alexander Fleming stumbled across penicillin—the first antibiotic drug—scientists knew our fight with evolution was on.

Most antibiotics work by blocking biological processes that allow bacteria to thrive and multiply. With prolonged, low-dosage use, however, antibiotics become a source of pressure that forces bacteria to evolve—and because these microorganisms are extremely adept at swapping and sharing bits of their DNA, when one member becomes resistant, so does most of its population.

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Mar 8, 2020

Chiral Higgs Mode in Nematic Superconductors

Posted by in categories: energy, evolution

Nematic superconductivity with spontaneously broken rotation symmetry has recently been reported in doped topological insulators, M x Bi 2 Se 3 (M = Cu, Sr, Nb). Here we show that the electromagnetic (EM) response of these compounds provides a spectroscopy for bosonic excitations that reflect the pairing channel and the broken symmetries of the ground state. Using quasiclassical Keldysh theory, we find two characteristic bosonic modes in nematic superconductors: the nematicity mode and the chiral Higgs mode. The former corresponds to the vibrations of the nematic order parameter associated with broken crystal symmetry, while the latter represents the excitation of chiral Cooper pairs. The chiral Higgs mode softens at a critical doping, signaling a dynamical instability of the nematic state towards a new chiral ground state with broken time reversal and mirror symmetry. Evolution of the bosonic spectrum is directly captured by EM power absorption spectra. We also discuss contributions to the bosonic spectrum from subdominant pairing channels to the EM response.

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