Biology subjects

Downing, P. A.

Publications and source records attributed to Downing, P. A..

4 recordsLinked to original sources

bioRxiv2025

A novel supergene controls queen size and colony social organization in the ant Myrmica ruginodis

In some ant species, the size of queens is dimorphic, with larger queens dispersing to form single-queen colonies and smaller queens remaining in natal colonies as part of multiple-queen societies. These alternative reproductive strategies influence colony kin structure and worker behavior, and their many independent origins make them ideal systems to study parallel evolution of genome organization and adaptability. We investigate the genetic basis of alternative reproductive strategies in the queen-size dimorphic ant Myrmica ruginodis by sampling 95 queens from 31 colonies in southern Finland. Whole-genome sequencing revealed a novel 9 Mb supergene associated with both queen size and social organization. Queens homozygous for the AA haplotype were larger and found only in single-queen colonies, while queens in multiple-queen colonies were smaller and contained only AB and BB genotypes. This supergene is not homologous to previously identified supergenes in ants, suggesting it was formed by a unique evolutionary pathway.

evolutionary biology↗

bioRxiv2024

Divergent selection and plasticity shape reproductive isolation at the onset of speciation

Reproductive isolation is a key process during speciation, but the factors that shape its evolution during the early stages of speciation remain largely unknown. Using a meta-analysis of 34 experimental speciation studies, we show that populations that experience divergent selection evolved stronger reproductive isolation compared to populations that evolved in similar environments, consistent with ecological speciation theory. However, and contrary to predictions, reproductive isolation did not increase with the number of generations. We present evidence that phenotypic plasticity could play a role in explaining these results, as divergent environments induce an increase in reproductive isolation in the first few generations. Our results highlight that adaptation to different environments in conjunction with plasticity can lead to a rapid increase in reproductive isolation at the beginning of speciation.

evolutionary biology↗

bioRxiv2023

Keywords to success: a practical guide to maximise the visibility and impact of academic papers

In a growing digital landscape, enhancing the discoverability and resonance of scientific articles is essential. Here, we offer ten recommendations to amplify the discoverability of studies in scientific databases. Particularly, we argue that the strategic use and placement of key terms in the title, abstract, and keyword sections can boost indexing and appeal. By surveying 237 journals in ecology and evolutionary biology, we found that current author guidelines may unintentionally limit article discoverability. Our survey of 5842 studies revealed that authors frequently exhaust abstract word limits -- particularly those capped under 250 words. This suggests that current guidelines may be overly restrictive and not optimised to increase the dissemination and discoverability of digital publications. Additionally, 91.9% of studies used redundant keywords in the title or abstract, undermining optimal indexing in databases. We encourage adopting structured abstracts to maximise the incorporation of key terms in titles, abstracts, and keywords. In addition, we encourage the relaxation of abstract and keyword limitations in journals with strict guidelines, and the inclusion of multilingual abstracts to broaden global accessibility. These evidence-based recommendations to editors are designed to improve article engagement and facilitate evidence synthesis, thereby aligning scientific publishing with the modern needs of academic research.

scientific communication and education↗

bioRxiv2020

Genetic sex determination and sex-specific lifespan in tetrapods - evidence of a toxic Y effect

Sex-specific lifespans are ubiquitous across the tree of life and exhibit broad taxonomic patterns that remain a puzzle, such as males living longer than females in birds and vice versa in mammals. The prevailing "unguarded-X" hypothesis (UXh) explains this by differential expression of recessive mutations in the X/Z chromosome of the heterogametic sex (e.g., females in birds and males in mammals), but has only received indirect support to date. An alternative hypothesis is that the accumulation of deleterious mutations and repetitive elements on the Y/W chromosome might lower the survival of the heterogametic sex ("toxic Y" hypothesis). Here, we report lower survival of the heterogametic relative to the homogametic sex across 138 species of birds, mammals, reptiles and amphibians, as expected if sex chromosomes shape sex-specific lifespans. We then analysed bird and mammal karyotypes and found that the relative sizes of the X and Z chromosomes are not associated with sex-specific lifespans, contrary to UXh predictions. In contrast, we found that Y size correlates negatively with male survival in mammals, where toxic Y effects are expected to be particularly strong. This suggests that small Y chromosomes benefit male lifespans. Our results confirm the role of sex chromosomes in explaining sex differences in lifespan, but indicate that, at least in mammals, this is better explained by "toxic Y" rather than UXh effects.

evolutionary biology↗