Preprints
Filtering by Subject: Evolution
Toward a General Theory of Heteromorphic Reproduction
Published: 2026-09-30
Subjects: Ecology and Evolutionary Biology, Evolution, Life Sciences, Other Ecology and Evolutionary Biology, Research Methods in Life Sciences
Organisms often divide reproductive investment among outputs that differ in morphology, timing, or reproductive mechanism. In this paper I extend the minimum-risk treatment of seed heteromorphism to the more general question of organisms with ‘portfolios’ of biologically distinct reproductive outputs. The resulting framework specifies a common investment and fitness currency, calculates returns [...]
On the Promise (and Practice) of Deep Comparative Methods: Expressivity, Limitations, and Design
Published: 2026-09-28
Subjects: Artificial Intelligence and Robotics, Biodiversity, Ecology and Evolutionary Biology, Evolution
Comparative biologists explain the diversity of organismal form and function by deciding which traits to measure and which evolutionary processes to model. These decisions make inference possible, but they also confine it to traits, relationships, and processes that can be specified a priori. Neural networks can expand this space, learning characters directly from complex observations and [...]
Multiple genetic routes to pelvic spine loss in brook stickleback
Published: 2026-09-10
Subjects: Biology, Ecology and Evolutionary Biology, Evolution, Life Sciences
Pelvic spine loss has evolved repeatedly in stickleback species and represents an intriguing opportunity to study genetically parallel adaptation. While previous work has identified key loci associated with this trait, the extent to which different populations rely on the same genetic mechanisms remains unclear. The genetic basis of pelvic spine loss in Culaea inconstans (Kirtland 1840) has only [...]
Q&A: Genetic Lineages
Published: 2026-09-02
Subjects: Evolution, Genetics, Population Biology
Genetic lineages are key to understanding evolution in complex scenarios and the evolution of genetic systems. However, they are often misunderstood; for example, confused with alleles or pedigrees. Here, we provide an accessible introduction to genetic lineages in question and answer format, from their definition as a physical object in space-time to their empirical characterization through [...]
Cell-autonomous immunity and the endosymbiotic theory: Septins at the origin?
Published: 2026-08-28
Subjects: Biology, Cell and Developmental Biology, Evolution, Life Sciences
The origin of complex eukaryotic cells remains a long-standing mystery. Endosymbiosis gave rise to mitochondria and chloroplasts, the bacteria-derived organelles that underpin eukaryotic productivity. Early eukaryotes had to establish these partnerships while avoiding pathogens, using limited ancestral tools. Septins are cytoskeletal GTP-binding proteins best known for roles in cytokinesis, yet [...]
The Defensive Repertoire of New World Coral Snakes: Evolution and Natural History
Published: 2026-08-21
Subjects: Behavior and Ethology, Ecology and Evolutionary Biology, Evolution
The defensive repertoire of New World coral snakes is diverse, but its evolutionary history remains poorly understood. We compiled 280 records of 11 defensive behaviors across 85 species of Micrurus and one species of Micruroides from the literature and contributions by researchers, naturalists, and wildlife photographers. Fifty-seven records represented behaviors not previously documented for [...]
Sleep elasticity: accessory, useful and vital components of a single state
Published: 2026-08-19
Subjects: Biology, Ecology and Evolutionary Biology, Evolution, Neuroscience and Neurobiology, Systems Biology
Sleep is universal, homeostatically defended and apparently costly, and for half a century this combination has been read as evidence of a vital, conserved function still awaiting identification. The search has not converged. Instead, it has accumulated a dozen candidate functions, each defensible but none commanding assent. I argue that the difficulty lies with the question rather than with the [...]
Cold adaptation in mammals: mechanisms and genomic insights from bats
Published: 2026-08-14
Subjects: Evolution, Genetics, Physiology
Cold environments impose strong energetic constraints on mammals, driving adaptations including thermogenesis, insulation and torpor. Bats are the only mammals capable of powered flight and inhabit different climates, yet the evolutionary basis of their cold tolerance remains poorly understood. In this study, we screened 571 records and retained 137 studies on mammalian cold adaptation. While [...]
Plant sex chromosome evolution in the phylogenomic era
Published: 2026-08-14
Subjects: Ecology and Evolutionary Biology, Evolution, Genetics and Genomics, Life Sciences, Plant Sciences
Plants harbor a tremendous diversity of sexual systems, including various forms of chromosomal sex determination that have arisen repeatedly across major clades, especially in angiosperms. The causes and consequences of sex chromosome evolution are far-reaching, with implications for sexual system, mating system, and life history evolution, genome architecture, and speciation, extinction, and [...]
Chromosomal speciation through holocentric lenses
Published: 2026-08-11
Subjects: Ecology and Evolutionary Biology, Evolution, Life Sciences
Chromosomal rearrangements (CRs) can trigger speciation by acting as barriers to gene flow. Two main theoretical frameworks were developed on how they contribute to speciation: causing infertility in heterokaryotypes (hybrid dysfunction) or creating islands of divergence through recombination suppression. However, these theories were developed with monocentric chromosomes in mind. Species with [...]
Beyond the mammalian nucleolus—a comparative perspective on nucleolar dynamics in stress and through the life cycle
Published: 2026-08-11
Subjects: Cell and Developmental Biology, Cell Biology, Ecology and Evolutionary Biology, Evolution, Microbiology, Organismal Biological Physiology
Classically the site of ribosomal RNA transcription, processing and early ribosome assembly, the nucleolus is increasingly understood as a dynamic multiphase condensate reshaped by cell state. Most reviews of this plasticity are mammal-centred. Here we set mammals alongside fungi, plants and animal germlines, following the nucleolus through the life cycle under environmental change and through [...]
The series of genetic codes that preceded our own
Published: 2026-08-01
Subjects: Evolution, Genetics, Paleobiology
We produce a working hypothesis for the steps by which the canonical genetic code might have been constructed. We assume amino acids were added in the order inferred from their enrichment or depletion in ancestrally reconstructed sequences dating back to the Last Universal Common Ancestor (LUCA) relative to that in ancient but post-LUCA controls. To convert this ordering into a time series of [...]
Nervous system centralization as the evolutionary scaffold for body segmentation: A review of the evidence
Published: 2026-07-29
Subjects: Developmental Biology, Ecology and Evolutionary Biology, Evolution, Integrative Biology, Life Sciences, Molecular Genetics
The evolutionary origins of two major bilaterian innovations, the centralized nervous system and the segmented body plan, have both been debated as cases of homology versus convergence, often using strikingly similar arguments. Here we review the comparative developmental genetics of both processes across the three segmented animal phyla (arthropods, annelids, and chordates) focusing on the [...]
Lactate Dehydrogenase as a Candidate Genomic Marker of Climate Change in Mammals?
Published: 2026-07-13
Subjects: Bioinformatics, Comparative and Evolutionary Physiology, Evolution, Genetics, Genomics, Molecular Genetics, Other Ecology and Evolutionary Biology, Population Biology
Climate change imposes metabolic and thermal stress on mammals, yet genomic markers that track lineage specific adaptation remain limited. Lactate dehydrogenase (LDH), a central enzyme in lactate metabolism and anaerobic stress response, has not previously been evaluated for its evolutionary association with climate change induced selection. Here, comparative genomics across 14 mammalian species [...]
RSV G selection analyses support constraint of the CX3C/cystine-noose core and diversification in mucin-like regions
Published: 2026-07-07
Subjects: Evolution
The RSV attachment (G) glycoprotein is a highly variable surface antigen and an important target of humoral immunity, yet it contains a short central conserved region (CCR; RSV-A2 residues 157-198) with a CX3C chemokine-mimic motif and disulfide-bonded cystine noose. A pre-specified hypothesis was tested: FEL-positive diversifying sites are enriched in the CCR and/or the CX3C motif. Using a [...]