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Category: evolution – Page 6

In their Review article earlier this year, Fedorenko, Ivanova & Regev (Fedorenko, E., Ivanova, A. A. & Regev, T. I. The language network as a natural kind within the broader landscape of the human brain. Nat. Rev. Neurosci. 25, 289–312 (2024))1 propose a functional separation between the core language network and other perceptual, motor and higher-level cognitive components of communication-related networks in the left hemisphere of the human brain. In the ‘Open questions and a way forward’1 section that ends their Review, the authors discuss the need for cross-species comparative research to disentangle how these brain networks came to support human language. Here, we suggest that the authors’ functional separation of a core language network and other components in the human brain is grounded in the evolution of two separate structural networks within primate brains.

Fedorenko and colleagues describe the core language network as left-lateralized, and involving the middle frontal gyrus (MFG), inferior frontal gyrus (IFG), superior temporal gyrus (STG) and middle temporal gyrus (MTG). Perceptual and motor systems for speech are defined as separate subsystems located in auditory cortex and speech perception areas in the STG and motor cortex and motor planning areas1, respectively. Importantly, these functionally defined key brain areas are known to be structurally connected via dorsally and ventrally located white-matter fibre tracts, which guarantee the information flow between areas. In humans, two separate dorsal pathways that provide structural connections have been identified for two distinct networks2,3 (Fig. 1).

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An international research team has used the James Webb Space Telescope (JWST) to observe massive galaxies discovered by the Subaru Telescope in a corner of the early universe known as the Spiderweb protocluster. The JWST results confirm what had been suggested from the Subaru Telescope observations, namely that supermassive black hole activity can truncate the growth of galaxies.

These results appear in the paper “Spider-Webb: JWST Near Infrared Camera resolved galaxy and nuclear activities in the Spiderweb protocluster at z=2.16” in Monthly Notices of the Royal Astronomical Society on December 18, 2024.

The growth and evolution of galaxies is a major theme in modern astronomy. The origin of giant elliptical galaxies is one riddle. These galaxies consist entirely of old stars, so something early in their evolution must have shut off star formation in the progenitors of giant elliptical galaxies. According to one theory, the at the hearts of the galaxies may play a role in determining the star formation.

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The LOREX experiment utilizes lorandite ore to gauge historical solar neutrino flux, revealing insights about the Sun’s development and climatic effects through advanced decay rate measurements.

The Sun, Earth’s life-sustaining powerhouse, generates immense energy through nuclear fusion while emitting a steady stream of neutrinos — subatomic particles that reveal its inner workings. While modern neutrino detectors shed light on the Sun’s current behavior, key questions remain about its stability over millions of years — a timeframe encompassing human evolution and major climate changes.

Addressing these questions is the mission of the LORandite EXperiment (LOREX), which depends on accurately determining the solar neutrino cross-section for thallium. An international team of scientists has now achieved this crucial measurement using the unique Experimental Storage Ring (ESR) at GSI/FAIR in Darmstadt. Their groundbreaking results, advancing our understanding of the Sun’s long-term stability, have been published in the journal Physical Review Letters.

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Eddie Gonzales Jr. – AncientPages.com – Despite awe-inspiring diversity, nearly every lifeform – from bacteria to blue whales – shares the same genetic code. How and when this code came about has been the subject of much scientific controversy.

Image credit: Adobe Stock – Diatomic

Taking a fresh approach at an old problem, Sawsan Wehbi, a doctoral student in the Genetics Graduate Interdisciplinary Program at the University of Arizona, discovered strong evidence that the textbook version of how the universal genetic code evolved needs revision. Wehbi is the first author of a study published in the journal PNAS suggesting the order with which amino acids – the code’s building blocks – were recruited is at odds with what is widely considered the “consensus” of genetic code evolution.

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Recent scientific efforts have advanced the development of a comprehensive primate evolutionary timetree, filling significant gaps in our understanding of primate biodiversity and evolutionary history.

The primate order includes not only humanity’s closest relatives—the seven great apes—but also more than 450 species of monkeys, lemurs, lorises, and galagos. This group is remarkably diverse, ranging from 400-pound gorillas to tiny mouse lemurs (Microcebus) that weigh just one ounce. Primates display some of the most fascinating behaviors in the animal kingdom: chimpanzees use sticks to ‘fish’ for termites in hollow logs, while orangutans fashion leaf gloves to handle prickly durian fruit.

Despite being among the most thoroughly studied animals on Earth, primates still lack a complete molecular phylogenetic tree—a comprehensive evolutionary map detailing when different species emerged and how they are related. A robust phylogenetic tree would use genetic data to trace the timing of species’ appearances and identify their closest evolutionary relatives. Currently, the largest molecular timetree for primates includes just over 200 species. Even the most extensive synthetic timetree, based on more than 4,000 published studies, covers only about 400 species, leaving roughly one-fifth of the primate evolutionary tree unresolved.

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Mosasaurs are extinct marine reptiles that dominated Earth’s oceans during the Late Cretaceous period.

Mosasaurs, extinct marine reptiles that dominated Earth’s oceans during the Late Cretaceous period, have fascinated scientists since their discovery in 1766 near Maastricht, Netherlands. These formidable lizards are iconic examples of macroevolution, showcasing the emergence of entirely new animal groups.

Michael Polcyn, a paleontologist from Utrecht University, has presented the most comprehensive study yet on their early evolution, ecology, and feeding biology. His findings, aided by advanced imaging technologies, provide fresh insights into the origins, relationships, and behaviors of these ancient giants.

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Astrocytes are star-shaped glial cells in the central nervous system that support neuronal function, maintain the blood-brain barrier, and contribute to brain repair and homeostasis. The evolution of these cells throughout the progression of Alzheimer’s disease (AD) is still poorly understood, particularly when compared to that of neurons and other cell types.

Researchers at Massachusetts General Hospital, the Massachusetts Alzheimer’s Disease Research Center, Harvard Medical School and Abbvie Inc. set out to fill this gap in the literature.

Their paper, published in Nature Neuroscience, provides one of the most detailed accounts to date of how different astrocyte subclusters respond to AD across different brain regions and disease stages, providing valuable insights into the cellular dynamics of the disease.

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Researchers have developed a method using viruses to track neuronal development in frogs, shedding light on the evolution of vertebrate nervous systems and offering comparative insights with mammals.

Although viruses are typically associated with illnesses, not all viruses are harmful or cause disease. Some are instrumental in therapeutic treatments and vaccinations. In scientific research, viruses are often used to infect certain cells, genetically modify them, or visualize neurons in the organism’s central nervous system (CNS)—the command center made up of the brain, spinal cord, and nerves.

The highlighting process has now been successfully applied to amphibians, which are crucial for understanding the brain and spinal cord of tetrapods—four-limbed animals, including humans. This has been shown in a new study by an international EDGE consortium jointly led by the Sweeney Lab at the Institute of Science and Technology Austria (ISTA) and the Tosches Lab at Columbia University.

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A study suggests that by the time H. sapiens expanded, the differentiation between the two species had progressed to the extent that they were distinct and recognizable as separate species.

A recent study conducted by researchers from London’s Natural History Museum and the Institute of Philosophy at KU Leuven has strengthened the argument that Neanderthals and modern humans (Homo sapiens) should be classified as distinct species to more accurately trace our evolutionary history.

Different researchers have different definitions as to what classifies as a species. It is undisputed that H. sapiens and Neanderthals originate from the same parental species, however studies into Neanderthal genetics and evolution have reignited the debate over whether they should be classed as separate from H. sapiens or rather a subspecies (H. sapiens neanderthalensis).

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