eukaryote Archives

Reconstruction of the ancestral LECA proteome and its metabolic features

Rethinking The Origin Of Our Cells As A Story Of Microbial Alliances

by Keith CowingJune 13, 2026June 13, 2026

All cells in animals, plants, fungi, and protists share a fundamental characteristic: they are eukaryotic cells—complex cells with specialized internal compartments. The cells that make up our bodies are no […]

Inferred subcellular organization in LECA, the last eukaryotic common ancestor, based on its estimated gene content. Credit Cell illustration adapted from multiple graphics shared as open source by SwissBioPics.

Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Nanotechnology & SynBio, Origin & Evolution of Life, Press Release

Scientists Reveal Disease Genes From Reconstruction Of Ancestor To All Complex Life

by Keith CowingMay 28, 2026May 28, 2026

A University of Texas at Austin-led team has reconstructed the most detailed map to date of the molecular machines that carried out the functions of life in an ancient ancestor […]

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 […]

A few highlights from the first recognition of Archaea to the cultivation of the first Asgard representatives and their cellular structures are shown. Symbols indicate the respective methods used. -- Springer Nature

Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Nomenclature, Systematics, Natural History, Origin & Evolution of Life, Status Report

Asgard Archaea: Have We Found Our Microbial Aancestors?

by Keith CowingMarch 19, 2026March 19, 2026

The discovery of Asgard archaea about a decade ago has greatly reshaped our understanding of archaeal evolution and the origin of eukaryotes.

In December 2025, Brett Baker led a research cruise to collect microbial genomes off the coast of Uruguay. In this photo, Tyler Smith pilots a remotely operated vehicle collecting shallow coastal sediments. Credit: Brett Baker.

AI - Data - Apps - Cybernetics, Away Teams & Field Reports, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Press Release, ROVs/Submersibles/Diving, Sample Return, Water/Hycean Worlds & Oceanography

A Break In A Longstanding Mystery About The Origin Of Complex Life

by Keith CowingFebruary 18, 2026February 18, 2026

The most widely accepted scientific explanation for the arrival of all complex life on Earth has had an unsolved mystery at its heart. According to the theory, all plants, animals […]

GC content, total number and their frequencies of PQS in H. volcanii genome. (A) Schematic presentation of a G-quartet (left) and a G-quadruplex (right). (B) Total PQS counts, percentage of GC and PQS frequency characteristics for the main chromosome and mini-chromosomes. (C,D) G4 prediction in H. volcanii’s promoters: number and localisation relative to the TSS. -- biorxiv.org

Biochemistry & Organic Chemistry, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report

Archaeal G-Quadruplexes: A Novel Model for Understanding Unusual DNA/RNA Structures Across the Tree of Life

by Keith CowingFebruary 10, 2026February 10, 2026

Archaea, a domain of microorganisms found in diverse environments including the human microbiome, represent the closest known prokaryotic relatives of eukaryotes.

Hypothetical sequence of events that led to the origin of the purple-green photosymbiosis of P. tenue. See main text for details. Note that all ancestors and extant species remain phagotrophic (or mixotrophic in the case of photosymbiosis). This study has revealed the order of endosymbiont acquisition in P. tenue and potential pre adaptations that facilitated the symbiosis. These insights have, in turn, shed light on the question of how two contrasting photosynthetic symbionts came to exist within the same host. Moreover, we have expanded the known diversity of the genus Pseudoblepharisma by discovering new non photosymbiotic species and confidently establishing the sister relationship between the genera Pseudoblepharisma and Spirostomum in the family Spirostomidae. Our genome-based predictions on the physiology of photosymbiotic Pseudoblepharisma species represent the basis for future experimental work on the identity of the metabolites that are exchanged among symbiotic partners. -- biorxiv.org

Biochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report

The Phylogenetic Context For The Origin Of A Unique Purple-green Photosymbiosis

by Keith CowingFebruary 9, 2026February 9, 2026

Symbioses are widespread in nature and have been the source of much evolutionary innovation. While some types of symbioses evolved multiple times across space and time (e.g., oxygenic photosymbioses or […]

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Microbiology & Virology, Origin & Evolution of Life, Press Release

Complex Life Developed Earlier Than Previously Thought, Nature Study Reveals

by Keith CowingDecember 3, 2025December 3, 2025

The research led by the University of Bristol was published in the scientific journal Nature 3 December, the research indicates that complex organisms evolved long before there were substantial levels […]

(d) Cryo-ET slice through a cell body of early-log phase Ca. Y. umbracryptum with multiple intracellular vesicles. Scale bar: 100 nm. (e) Semantic segmentation of the tomogram shown in panel d) depicting the cell membrane (pink), cell-surface proteins (pale green), pili (blue), ribosomes (grey), cytoskeletal filaments (yellow) and intracellular vesicles (orange). Scale bar: 100 nm. -- biorxiv.org

Away Teams & Field Reports, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Nanotechnology & SynBio, Sample Return, Status Report

An Asgard Archaeon With Internal Membrane Compartments

by Keith CowingDecember 3, 2025December 3, 2025

The emergence of eukaryotes from a merger between an archaeon and a bacterial cell ~two billion years ago involved a profound change in cellular organisation.

This figure presents a modern tree of Life, highlighting eukaryotes (organisms with complex cells) based on genome-scale analyses from Valt et al. (2025). The newly identified and ancient supergroup Disparia is shown alongside other major branches, including several formerly unplaced protist lineages and the new organism Solarion arienae. Colored dots mark the positions of well-known complex multicellular groups such as animals, plants, fungi, and seaweeds, providing familiar reference points on the tree. Built using large gene datasets and advanced phylogenomic tools (including PhyloFisher, originally developed in the Brown Lab), this tree illustrates how new genomic discoveries continue to reshape our understanding of early eukaryotic evolution. CREDIT Matthew W. Brown, Ph.D.

Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Nomenclature, Systematics, Natural History, Origin & Evolution of Life, Press Release

New Clues To Origins Of Complex Life Revealed

by Keith CowingNovember 21, 2025November 21, 2025

Mississippi State biologist Matthew W. Brown, the university’s Donald L. Hall Professor of Biology, is part of an international research team whose groundbreaking discovery is featured Nov. 19 in Nature—one […]