Researchers synthesize high-entropy liquid metal alloys at nanoscale, achieving atomic dispersion of noble metals and demonstrating enhanced catalytic activity for hydrogen evolution.
A newly discovered fossil snake species in Wyoming is transforming our understanding of snake evolution. Unearthed from a burrow where four well-preserved specimens were found intertwined, this species, named Hibernophis breithaupti, lived in North America 34 million years ago. This discovery provides valuable insights into the origins and diversification of boas and pythons.
Hibernophis breithaupti has unique anatomical features, in part because the specimens are articulated—meaning they were found all in one piece with the bones still arranged in the proper order—which is unusual for fossil snakes. Researchers believe it may be an early member of Booidea, a group that includes modern boas and pythons. Modern boas are widespread in the Americas, but their early evolution is not well understood. These new and very complete fossils add important new information, in particular, on the evolution of small, burrowing boas known as rubber boas.
Researchers have confirmed the presence of an intermediate-mass black hole in the core of Omega Centauri, a cluster that once formed the heart of a separate galaxy. This finding enhances our understanding of black hole evolution and galaxy dynamics. (Artist’s concept.) Credit: SciTechDaily.com.
Researchers confirmed an intermediate-mass black hole in Omega Centauri’s center, supporting theories of its origin as a distinct galaxy core merged with the Milky Way.
Continue reading “Omega Centauri: A Galaxy Core Frozen in Time Reveals Its Black Hole” »
Could an exoplanet’s that is tidally locked to its parent star exhibit differences in atmospheric behavior at the boundary of its permanent dayside and permanent nightside, also known as the terminator? This is what a recent study published in Nature hopes to address as a team of international researchers investigated the unique atmosphere of WASP-39 b, whose radius is just under 1.3 times that of Jupiter, orbits in just 4.1 days, and is located just under 700 light-years from Earth. This study holds the potential to help scientists better understand the formation and evolution of exoplanet atmospheres, specifically once that are tidally locked to their parent star.
Artist’s rendition of WASP-39 b’s terminator. (Credit: NASA, ESA, CSA, R. Crawford (STScI))
“WASP-39 b has become a sort of benchmark planet in studying the atmosphere of exoplanets with Webb,” said Dr. Néstor Espinoza, who is an Assistant Astronomer and Mission Scientist for Exoplanet Science at the Space Telescope Science Institute (STScI) and lead author on the study. “It has an inflated, puffy atmosphere, so the signal coming from starlight filtered through the planet’s atmosphere is quite strong.”
Apple presents MUSCLE A Model Update Strategy for Compatible LLM Evolution.
Apple presents MUSCLE
A model update strategy for compatible LLM evolution.
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In new research, Arizona State University scientists and their colleagues investigated genetic changes occurring in a naturally isolated population of the water flea, Daphnia pulex. This tiny crustacean, barely visible to the naked eye, plays a crucial role in freshwater ecosystems and offers a unique window into natural selection and evolution.
By analyzing co-evolution of mitochondrial and nuclear genomes across insect species, the authors uncover the evolutionary covariation of a group of non-mitochondrially targeted nuclear genes with mitochondrial genes, including the uncharacterized gene CG11837, which regulates insect lifespan.
A long-term study since 1929 has revealed significant insights into barley’s evolution, showing its adaptation to different environments and the substantial impact of natural selection. This research underscores the limitations of evolutionary breeding and highlights the need for further exploration to enhance crop yields.
Utilizing one of the world’s oldest biological experiments, which commenced in 1929, researchers have revealed how barley, a major crop, has been influenced by agricultural pressures and its evolving natural environment. These findings highlight the significance of long-term studies in comprehending the dynamics of adaptive evolution.
The survival of cultivated plants after their dispersal across different environments is a classic example of rapid adaptive evolution. For example, barley, an important neolithic crop, spread widely after domestication over 10,000 years ago to become a staple source of nutrition for humans and livestock throughout Europe, Asia, and Northern Africa over just a few thousand generations. Such rapid expansion and cultivation have subjected the plant to strong selective pressures, including artificial selection for desired traits and natural selection by being forced to adapt to diverse new environments.
LA JOLLA (March 4, 2024)—Charles Darwin described evolution as “descent with modification.” Genetic information in the form of DNA sequences is copied and passed down from one generation to the next. But this process must also be somewhat flexible, allowing slight variations of genes to arise over time and introduce new traits into the population.
But how did all of this begin? In the origins of life, long before cells and proteins and DNA, could a similar sort of evolution have taken place on a simpler scale? Scientists in the 1960s, including Salk Fellow Leslie Orgel, proposed that life began with the “RNA World,” a hypothetical era in which small, stringy RNA molecules ruled the early Earth and established the dynamics of Darwinian evolution.
New research at the Salk Institute now provides fresh insights on the origins of life, presenting compelling evidence supporting the RNA World hypothesis. The study, published in Proceedings of the National Academy of Sciences (PNAS) on March 4, 2024, unveils an RNA enzyme that can make accurate copies of other functional RNA strands, while also allowing new variants of the molecule to emerge over time. These remarkable capabilities suggest the earliest forms of evolution may have occurred on a molecular scale in RNA.
Numerous open questions in gravity theory become apparent from observations in cosmology, such as the cosmic microwave background radiation [1, 2, 3, 4, 5, 6], the large scale structure [7, 8], gravitational waves [9, 10] and supernovae [11]. In order to describe these observations, one needs to study the evolution of both the universe as a whole, modeled by a homogeneous and isotropic background geometry and matter distribution, as well as perturbations of this background. A thorough understanding of such cosmological perturbations and their dynamics imposed by the gravitational interaction is therefore an important necessity for describing and explaining the modern observations in cosmology.
Cosmological perturbations in gravity have been studied for a long time, starting with the case of (pseudo-)Riemannian spacetime geometry, which is employed by the standard formulation of general relativity and the most well-known class of its extensions, in which the gravitational interaction is attributed to the curvature of the metric-compatible, torsion-free Levi-Civita connection [,13,14,15]. This task is significantly simplified by the fact by understanding how perturbations transform under gauge transformations, i.e., infinitesimal diffeomorphisms which retain the nature of the spacetime geometry as a small perturbation of a cosmologically symmetric background. From these gauge transformations, one can derive a set of gauge-invariant perturbation variables, which describe the physical information contained in the metric perturbations as well as the perturbations of the matter variables, so that they become independent of the arbitrary gauge choice. The resulting gauge-invariant perturbation theory is one of the cornerstones of modern cosmology [16,17,18,19].
Despite its overwhelming success in describing observations from laboratory scales up to galactic scales, general relativity is challenged by the aforementioned open questions, as well as the open question how it can be reconciled with quantum theory. This situation motivates the study of modified gravity theories [20]. While numerous theories depart from the standard formulation of general relativity in terms of the curvature of the Levi-Civita connection of a Riemannian spacetime, also other formulations in terms of the torsion or nonmetricity of a flat connection exist and can be used as potential starting points for the construction of modified gravity theories [21, 22]. Focusing on general relativity alone, one finds that these formulations are equivalent in the sense that they lead to field equations which possess the same solutions for the metric irrespective of the geometric properties of the connection under consideration…
