Lifeboat Foundation

Viral DNA in human genomes, embedded there from ancient infections, serves as antivirals that protect human cells against certain present-day viruses, according to new research.

The paper, “Evolution and Antiviral Activity of a Human Protein of Retroviral Origin,” published Oct. 28 in Science, provides proof of principle of this effect.

Previous studies have shown that fragments of ancient viral DNA—called endogenous retroviruses —in the genomes of mice, chickens, cats and sheep provide immunity against modern viruses that originate outside the body by blocking them from entering host cells. Though this study was conducted with human cells in culture in the lab, it shows that the antiviral effect of endogenous retroviruses likely also exists for humans.

Astronomers have discovered a mysterious neutron star that’s far lighter than previously thought possible, undermining our understanding of the physics and evolution of stars. And fascinatingly, it may be composed largely of quarks.

As detailed in a new paper published in the journal Nature Astronomy this week, the neutron star has a radius of just 6.2 miles and only the mass of 77 percent of the Sun.

That makes it much lighter than other previously studied neutron stars, which usually have a mass of 1.4 times the mass of the Sun at the same radius.

SARS-CoV-2 is evolving “rapidly,” spawning one new variant after another. But omicron continues to dominate, raising new questions about how evolution of the virus is headed.

An international team of scientists has found toothed fish remains that date back 439 million years, which suggests that the ancestors of modern chondrichthyans (sharks and rays) and osteichthyans (ray-and lobe-finned fish) originated far earlier than previously believed.

The findings were recently published in the prestigious journal Nature.

Continue reading “439-Million-Year-Old Fossil Teeth Overturn Long-Held Views About Evolution” »

Billions of years ago, a version of planet Earth that looked very different than the one we live on today was hit by an object about the size of Mars, called Theia – and out of that collision the Moon was formed. How exactly that formation occurred is a scientific puzzle researchers have studied for decades, without a conclusive answer.

Until now, most theories have claimed that the Moon formed out of the debris of this collision, coalescing in orbit over months or years. However, a new simulation presents a different outcome – the Moon may have formed immediately, in a matter of hours, when material from the Earth and Theia was launched directly into orbit after the impact.

“This opens up a whole new range of possible starting places for the Moon’s evolution,” said Jacob Kegerreis, a postdoctoral researcher at NASA’s Ames Research Center in California and lead author of a paper this month in The Astrophysical Journal Letters. “We went into this project not knowing exactly what the outcomes of these high-resolution simulations would be. So, on top of the big eye-opener that standard resolutions can give you misleading answers, it was extra exciting that the new results could include a tantalisingly Moon-like satellite in orbit.”

Strange libraries of supplementary genes nicknamed “Borg” DNA appear to supercharge the microbes that possess them, giving them an uncanny ability to metabolize materials in their environment faster than their competitors.

By learning more about the way organisms use these unusual extrachromosomal packets of information, researchers are hoping to find new ways of engineering life to take a big bite out of methane emissions.

In the wake of a study publicized last year (and now published in Nature), researchers have continued to analyze the diversity of sequences methane-munching microbes store in these unusual genetic depositaries in an effort to learn more about the evolution of life.

Summary: In a highly competitive environment, Trinidadian killifish grow larger brains. This neuro-evolution allows for greater fitness and survival rates.

Source: UT Arlington.

In response to a high-competition environment, Trinidadian killifish evolve larger brains, increasing their fitness and survival rates, according to a new study in Ecology Letters by biologists at The University of Texas at Arlington.

A simple two-carbon compound may have been a crucial player in the evolution of metabolism before the advent of cells, according to a new study published October 4 in the open access journal PLOS Biology, by Nick Lane and colleagues of University College London, U.K. The finding potentially sheds light on the earliest stages of prebiotic biochemistry, and suggests how ATP came to be the universal energy carrier of all cellular life today.

ATP, adenosine triphosphate, is used by all cells as an energy intermediate. During cellular respiration, energy is captured when a phosphate is added to ADP (adenosine diphosphate) to generate ATP; cleavage of that phosphate releases energy to power most types of cellular functions. But building ATP’s complex chemical structure from scratch is energy intensive and requires six separate ATP-driven steps; while convincing models do allow for prebiotic formation of the ATP skeleton without energy from already-formed ATP, they also suggest ATP was likely quite scarce, and that some other compound may have played a central role in conversion of ADP to ADP at this stage of evolution.

The most likely candidate, Lane and colleagues believed, was the two-carbon compound acetyl phosphate (AcP), which functions today in both bacteria and archaea as a metabolic intermediate. AcP has been shown to phosphorylate ADP to ATP in water in the presence of iron ions, but a host of questions remained after that demonstration, including whether other small molecules might work as well, whether AcP is specific for ADP or instead could function just as well with diphosphates of other nucleosides (such as guanosine or cytosine), and whether iron is unique in its ability to catalyze ADP phosphorylation in water.

Astrophysicists have performed a powerful new analysis that places the most precise limits yet on the composition and evolution of the universe. With this analysis, dubbed Pantheon+, cosmologists find themselves at a crossroads.

Pantheon+ convincingly finds that the cosmos is composed of about two-thirds dark energy and one-third matter—mostly in the form of dark matter—and is expanding at an accelerating pace over the last several billion years. However, Pantheon+ also cements a major disagreement over the pace of that expansion that has yet to be solved.

By putting prevailing modern cosmological theories, known as the Standard Model of Cosmology, on even firmer evidentiary and statistical footing, Pantheon+ further closes the door on alternative frameworks accounting for dark energy and dark matter. Both are bedrocks of the Standard Model of Cosmology but have yet to be directly detected and rank among the model’s biggest mysteries. Following through on the results of Pantheon+, researchers can now pursue more precise observational tests and hone explanations for the ostensible cosmos.