Origin & Evolution of Life Archives

Orthographic projection of ISS data (Karkoschka et al. 2017) for Selk-centered hemisphere. (dashed inset) SAR regional mosaic colored with elevation data from Corlies et al. (2017). Source: Selection and Characteristics of the Dragonfly Landing Site near Selk Crater, Titan, The Planetary Science Journal

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Origin & Evolution of Life, Robotics/Rovers/UAVs, Status Report, Titan, Tricorders & Sensors

Prebiotic Chemistry Insights for Dragonfly II: Thermodynamic Favorability of Nucleobases, Ribose, and Fatty Acids in Selk Crater on Titan

by Keith CowingApril 20, 2026April 20, 2026

Saturn’s moon Titan is a prime destination for investigating prebiotic chemistry beyond Earth, particularly at impact crater sites where transient liquid water may have enabled aqueous reactions between organic molecules.

Scanning tunneling microscope image of a molecule from the Ryugu sample. b Atomic force microscope image acquired by the multi-pass method. c Processed image of (b). Ring structure is overlaid. The colors are the same as in Fig. 1, but orange represents an eight-membered ring. Red arrows in (a, b) indicate a single CO molecule. The scale bars are 1 nm. -- Nature Communications

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Origin & Evolution of Life, Press Release, Sample Return

Discovery Of Unexpectedly Large Organic Molecules from Asteroid Ryugu

by Keith CowingApril 15, 2026April 15, 2026

Overview Using a high-resolution atomic force microscope ( AFM ), we directly observed the skeletal structures of individual organic molecules extracted from the Ryugu sample. We discovered numerous gigantic organic […]

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Enceladus, Habitable Zones, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

From Early Earth to Enceladus – Mineral Electrochemistry Could Drive Organic Synthesis

by Keith CowingApril 13, 2026April 13, 2026

At some point in Earth’s history, chemistry transitioned from abiotic organic synthesis—the building of more complicated organic molecules from smaller ones by nonbiological means—to biochemistry.

Astrochemistry, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Habitable Zones, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

Mineral-facilitated Aqueous Synthesis Of Hydrogen Cyanide From Prebiotically Abundant Amino Acids For Chemical Evolution

by Keith CowingApril 13, 2026May 4, 2026

Recent advances in prebiotic chemistry suggest that hydrogen cyanide (HCN) serves as a fundamental precursor for nearly all essential biomolecules and protometabolic processes for life’s emergence.

Evidence for ribozyme mass extinction. (A) Abundance distribution across all ten known small self-cleaving ribozyme families, showing the hammerhead's 91% dominance, a pattern characteristic of disaster taxa following mass extinction events. (B) Circular phylogeny of 80,548 unique hammerhead sequences colored by host taxonomic group. The star-like topology is consistent with post-bottleneck radiation, and the interspersion of distantly related host phyla around the tree reflects repeated independent colonization events rather than co-speciation, consistent with horizontal transfer of a single dominant survivor lineage. (C) Null distribution tests for Tajima's D (left) and Fu's Fs (right), each based on 10,000 coalescent replicates (n = 200, S = 40). Blue and orange histograms show the null distributions under neutral expectations; red dashed lines indicate the observed values (D = +2.28, upper-tail p = 0.013; Fs = −618.0, p < 0.0001). Observed D falls in the extreme upper tail (98.7% of null replicates below observed), indicating deep hierarchical structure; observed Fs falls far below any null replicate, indicating massive haplotype excess. The discordance between positive D and extremely negative Fs is diagnostic of ancient divergence preserved through a bottleneck followed by rapid within-lineage expansion. Full-sample values (n = 5,036) are D = +3.79, Fs = −690.8. -- biorxiv.org

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report

A Ribozyme Mass Extinction At The RNA-cellular Boundary And Its Potential Imprint On The Genetic Code

by Keith CowingApril 13, 2026April 13, 2026

The transition from the RNA world to cellular life remains one of the least understood events in the history of biology.

Structural features of Nerearchaeum marumarumayae cell -- Current Biology

Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Press Release, Sample Return

From Asgard to Earth: Tiny Discoveries Hold Clues To Life’s Greatest Leap

by Keith CowingApril 10, 2026April 10, 2026

Stromatolites – and their close relatives, microbial mats – could be mistaken for what seems like a bunch of old dark rocks. But instead, they are dense, layered communities of […]

Correlations of Asgardarchaeota with other microbial lineages in DAN-LK4 microbial mats inferred by co-occurrence network analyses. a, Sankey plot showing positive correlations of Asgard archaeal orders based on normalized USCGs (RPKM) inferred by SparCC alongside their distribution across the redox gradient in the indigenous and mesocosm-maintained microbial mat. The size of boxes is proportional to the relative abundance of Asgard archaea (center) and the number of links with prokaryotic taxa (left) in co-occurrence networks. The relative abundance of the different asgardarchaeal orders is indicated by the thickness of links connecting with the different mat layers (right). -- biorxiv.org

Away Teams & Field Reports, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Microbiology & Virology, Origin & Evolution of Life, Sample Return, Status Report

Redox distribution Of Asgard Archaea And Co-occurring Taxa In Microbial Mats From An Early Proterozoic Ecosystem Analog

by Keith CowingApril 9, 2026April 9, 2026

Eukaryotes originated from the symbiosis of an Asgard archaeon, the alphaproteobacterial ancestor of mitochondria, and possibly additional bacterial contributions.

A deuterostome cambroernid fossil from the Jiangchuan Biota and artist’s reconstruction (IMAGE)

Away Teams & Field Reports, Biosignatures & Paleobiology, Fossils & Paleontology, Origin & Evolution of Life, Press Release, Sample Return

Spectacular Fossil Treasure Trove Pushes Back Origins Of Complex Animals

by Keith CowingApril 8, 2026April 8, 2026

A newly discovered fossil site in southwest China has transformed our understanding of how complex animal life emerged on Earth, revealing that many key animal groups had already evolved before […]

Chemical processes in molecular clouds, such as grain-surface reactions and reactions in the gas phase, yield fundamental molecules, such as water, methanol, and ammonia. After experiencing further processes induced by energetic particles such as vacuum ultraviolet (VUV) photons and cosmic rays in the pre- or protosolar nebula stage, as well as (hydro)thermal events occurring on Solar System bodies after their formation, further complex organic molecules, such as those found in Bennu, Ryugu, and carbonaceous meteorites, may have been synthesized. (Image credit: NAOJ, NASA).

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Genomics, Proteomics, Bioinformatics, Meteorites & Asteroids, Missions & Hardware, Origin & Evolution of Life, Panspermia, Sample Return, Status Report

Distribution Of Extraterrestrial Nucleobases, Other N-heterocycles, And Their Precursors In A Sample From Asteroid Bennu

by Keith CowingApril 8, 2026April 8, 2026

The recent discovery of all five canonical nucleobases in samples from Bennu provides compelling evidence that some of life’s ingredients were synthesized abiotically in the parent body of this asteroid […]

Relationship between total group age T and crown group age tcg across various diversification rates λ − µ, equation 4. The heatmap represents the crown group age for a given rate and total group age (isolines are presented for reference). The orange dot-dashed line is the minimum value for T to fit the observed eukaryotic-grade fossil record of the late Palaeoproterozoic (1780 Ma), the red-dashed isoline is the minimum age for tcg fitting the observed crown-eukaryote fossil record from the end of the Mesoproterozoic (1050 Ma), and the grey interval is the range of possible tcg require to obtain the living diversity for a given rate and total age. The isolines for late LECA (tcg = 1200) or generous late LECA (tcg = 1400 Ma) are the red-dotted lines. -- biorxiv.org

Biosignatures & Paleobiology, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Habitable Zones, Microbiology & Virology, Origin & Evolution of Life, Sample Return, Status Report

Clade Dynamics Support An Early Origin Of Crown Eukaryotes

by Keith CowingApril 7, 2026April 7, 2026

The timing of the last eukaryotic common ancestor (LECA) remains a fundamental question in evolutionary biology and palaeontology. Unambiguous eukaryotic-grade fossils appear from 1780 Ma, but no crown-group supergroups are […]

Origin & Evolution of Life

Prebiotic Chemistry Insights for Dragonfly II: Thermodynamic Favorability of Nucleobases, Ribose, and Fatty Acids in Selk Crater on Titan

Discovery Of Unexpectedly Large Organic Molecules from Asteroid Ryugu

From Early Earth to Enceladus – Mineral Electrochemistry Could Drive Organic Synthesis

Mineral-facilitated Aqueous Synthesis Of Hydrogen Cyanide From Prebiotically Abundant Amino Acids For Chemical Evolution

A Ribozyme Mass Extinction At The RNA-cellular Boundary And Its Potential Imprint On The Genetic Code

From Asgard to Earth: Tiny Discoveries Hold Clues To Life’s Greatest Leap

Redox distribution Of Asgard Archaea And Co-occurring Taxa In Microbial Mats From An Early Proterozoic Ecosystem Analog

Spectacular Fossil Treasure Trove Pushes Back Origins Of Complex Animals

Distribution Of Extraterrestrial Nucleobases, Other N-heterocycles, And Their Precursors In A Sample From Asteroid Bennu

Clade Dynamics Support An Early Origin Of Crown Eukaryotes

Impact Crater Hydrothermal Systems Support Rapid Microbial Enrichment and Diverse Metabolic Potential

Photometric and Spectroscopic Observations of Comet 2P/Encke’s Nucleus in the Mid-Infrared Wavelength Region

A New Method Maps An Exoplanet’s True Shape

Wavefront-Conditioned Photon Measurements for Exoplanet Spectroscopy: Contrast Limits and Conditional Gains

ExoPAG 35 – Early Career Talks Invitation