All articles tagged with #origin of life
New geochemical data and molecular-clock analysis suggest life could have arisen during Earth's fiery Hadean period, about 4.4–4.2 billion years ago, with LUCA as the Last Universal Common Ancestor and LECA leading to modern eukaryotes; evidence points to liquid water despite extreme conditions, and ongoing genome recovery efforts may further refine when these ancestral stages appeared.
A Nature Astronomy study confirms all five DNA/RNA nucleobases—adenine, guanine, cytosine, thymine, and uracil—are present in Ryugu asteroid samples, suggesting primitive space rocks can carry the building blocks of life and revealing a correlation with ammonia that points to a novel nucleobase formation pathway.
New analysis of asteroid Ryugu samples detected all five canonical nucleobases—adenine, guanine, cytosine, thymine and uracil—showing DNA/RNA building blocks may be widespread in the solar system and could have seeded Earth’s prebiotic chemistry, with Bennu and meteorites providing supporting comparisons.
A Nature Astronomy study analyzing Hayabusa2’s Ryugu samples found all five nucleobases—the DNA/RNA building blocks—supporting the idea that asteroids delivered the ingredients for life to early Earth. The researchers note Ryugu has roughly equal amounts of purine and pyrimidine bases, unlike some meteorites, and that ammonia concentration may influence nucleobase formation, suggesting such molecules could have been more widespread in the early solar system.
New evidence from deep-sea rock cores near hydrothermal vents shows minerals can drive abiotic nitrogen reduction, producing ammonium and other nutrients that could fuel early life and help explain how a warmer, gas-rich early Earth maintained liquid water despite a fainter Sun.
New Gaia-based research suggests the Sun and many Sun-like stars formed at similar times and distances from the Milky Way’s center and likely migrated outward from the galactic core about 4–6 billion years ago as the Milky Way’s central bar evolved. This outward journey could have placed our solar system in a calmer outer disk for much of its history, potentially aiding Earth’s habitability and the emergence of life. The findings stem from two astronomy studies analyzing ~6,600 solar twins within ~1,000 light-years and will be broadened with upcoming Gaia data.
A new paper argues that life may have started within surface-attached, jelly-like gels on rocks, which could trap and organize reactive molecules, shield delicate chemistry from UV and heat, and support the emergence of metabolism and polymers before membrane-bound cells.
A Nature study analyzing deep-sea sediments found Heimdallarchaeia genomes with components of aerobic respiration, suggesting Asgard archaea could tolerate and potentially use oxygen long before Earth’s oxygenation, providing metabolic groundwork for the archaeal–eukaryotic merger that gave rise to complex life.
Researchers identified QT-45, a 45-base RNA ribozyme that can act like a tiny polymerase to copy RNA strands and, crucially, can synthesize a copy of its own sequence by base-pairing with a template. In tests, QT-45 copied various RNAs with about 95% fidelity (roughly 2–3 errors per copy), though the process is slow. This demonstrates self-replicating RNA is plausible at very small sizes and could be refined by evolution under prebiotic conditions.
A University of Sydney doctoral student creates tiny cosmic-dust analogues in the lab by exciting a mix of nitrogen, carbon dioxide and acetylene with 10,000 volts of electricity, reproducing conditions around stars to study how dust catalyzes organic molecules and potentially seeded life; the team aims to build a database of dust types to compare with meteorites and astronomical observations.
Researchers modeling frozen hydrogen cyanide find it converts to hydrogen isocyanide, enabling two pathways to prebiotic molecules like amino acids and nucleobases, even in extreme cold. The work suggests cyanide-based chemistry could have seeded life on early Earth and may occur on icy worlds such as Titan or in other planetary atmospheres across the solar system.
Scientists describe the Lost City hydrothermal field off the Mid-Atlantic Ridge, featuring calcite chimneys up to 60 meters tall and vents that emit hydrogen- and methane-rich fluids, supporting life without magma heat and potentially shedding light on how life began on Earth and perhaps on icy worlds; a 2024 1,268‑meter mantle rock core from the site could hold crucial clues, and the ecosystem’s uniqueness and mining threats have spurred calls to protect it, potentially as a World Heritage site.
New computer simulations suggest solid hydrogen cyanide crystals in cold environments have reactive surfaces that can convert HCN into hydrogen isocyanide, enabling formation of complex prebiotic molecules and potentially driving the origin of life; researchers plan lab tests to verify these surface-catalyzed reactions.
New experiments support the 'RNA world' hypothesis by demonstrating how RNA could have formed on early Earth, with borates playing a beneficial role in stabilizing RNA components, suggesting a plausible pathway for the origin of life around 4.3 billion years ago, possibly delivered by asteroid impacts.
The article explores the hypothesis that life on Earth may have originated from microorganisms on Mars, which could have been transported via meteorites. It discusses the timing of planetary formation, early conditions on Mars and Earth, and the challenges of microbial survival during space travel, ultimately questioning whether Earth’s life could have come from Mars or if it originated independently on Earth.