Biology subjects

Konar, B.

Publications and source records attributed to Konar, B..

2 recordsLinked to original sources

bioRxiv2026

The genomic basis of evolutionary stasis in the 500-million-year-old red seaweed genus Ahnfeltia

The red seaweed genus Ahnfeltia is an ancient lineage that has persisted for over 500 million years with remarkably limited diversification despite a global distribution in cold-temperate intertidal habitats. Compared to the highly diverse sister lineage, Rhodymeniophycidae, Ahnfeltia provides a unique system for investigating long-term evolutionary persistence in marine macroalgae. Here, we generated chromosome-scale genomes from five populations across three species and combined population genomics with paleogeographic niche modelling. Our results reveal remarkable genomic conservation, strong geographic isolation with limited gene flow, high homozygosity, and evidence of purifying selection. Niche projections indicate long-term stability and spatial connectivity of suitable cold-temperate habitats. These findings suggest that Ahnfeltias persistence and limited diversification are linked to genomic constraints and stable ecological niches over geological timescales. This study provides new insights into the genomic basis of evolutionary stasis in ancient marine lineages and highlights potential vulnerability to ongoing climate change affecting cold-water coastal ecosystems.

evolutionary biology↗

bioRxiv2019

Marine deforestation leads to widespread loss of ecosystem function

Trophic interactions can result in changes to the abundance and distribution of habitat-forming species that dramatically reduce ecosystem health and functioning. Nowhere may this be as dramatic as in the coastal zone of the Aleutian Archipelago, where overgrazing by herbivorous sea urchins that began in the 1980s resulted in widespread deforestation of the regions kelp forests. Here we show that this deforestation resulted in decreased macroalgal and invertebrate abundance and diversity, increased benthic irradiances, and reduced rates of gross primary production and respiration by the ecosystem. These opposing metabolic processes remain in balance, however, which resulted in little-to-no changes to net ecosystem production. These patterns were consistent across nine islands spanning more than 1000 kilometers of the archipelago. In light of the worldwide declines in kelp forests observed in recent decades, our findings suggest that marine deforestation profoundly affects the health of coastal ecosystems and how they function. Significance statementWidespread marine deforestation results in reduced biodiversity and primary productivity throughout more than 1000 km of the Aleutian Archipelago.

ecology↗