03078nas a2200241 4500008004100000022001300041245011000054210006900164260001200233300001100245490000800256520229200264653002502556653002602581653002802607653002502635653002702660653001802687100001302705700002502718700002102743856007202764 2024 eng d a0929139300aAn Antarctic worm and its soil ecosystem: A review of an emerging research program in ecological genomics0 aAntarctic worm and its soil ecosystem A review of an emerging re c01/2024 a1051100 v1933 a

Relationships between the evolution of species and their ecosystems can be difficult to accurately assess due to the high number of confounding biological variables (e.g., biotic interactions among community members and the resulting complex relationships between genetic pathways and organism phenotypes). Thus, progress in ecological genomics by making inferences about fundamental ecological patterns and processes is hampered by high biodiversity and subsequent complex biotic interactions. Study systems that are naturally low in biological and ecological complexity, and strongly structured by abiotic drivers, can serve as models for bridging the gap between controlled mesocosm experiments and natural ecosystems. The terrestrial ecosystems of the Antarctic dry valleys have low biodiversity and constrained ecological complexity, primarily because ecological communities are so strongly shaped by physical, rather than biological, factors. The harsh constraints of the physical environment on organismal evolution and the structure of ecological communities make this an optimal natural system for disentangling the influence of specific environmental parameters on genotype/phenotype and gene by environment interactions. This work reviews the biology, evolution, and ecology of an emerging model organism, the free-living nematode Plectus murrayi, in a model ecosystem, the McMurdo Dry Valleys (MDVs) of Antarctica. In the MDVs, habitat suitability, including nutrient availability, has been shown to drive organismal (nematode) life history evolution, including growth and reproduction, primarily by way of changes in the expression of developmental genes. Changes in growth rates and reproductive schedules are accomplished primarily through alterations of nuclear rRNA gene copy number. The predicted and observed responses to natural experiments have been replicated in the laboratory, providing a synthesis of field observations and experimental evolution. Studying such natural model systems as this could fill several persistent knowledge gaps in our understanding of how genetic variation, genomic architecture, and gene regulation drive the genotype-phenotype paradigm, and the consequent effects of these drivers on ecosystem structure and functioning.

10aecological amplitude10aecological succession10aelemental stoichiometry10aextreme environments10alife history evolution10amodel systems1 aXue, Xia1 aThompson, Andrew, R.1 aAdams, Byron, J. uhttps://www.sciencedirect.com/science/article/pii/S092913932300308602076nas a2200313 4500008004100000245008700041210006900128260001200197300001100209490000800220520114900228653002801377653002701405653002401432653002401456653001301480653000901493100001301502700002501515700001601540700002201556700001701578700001801595700001601613700002401629700002001653700001701673856007201690 2023 eng d00aEcological stoichiometry drives the evolution of soil nematode life history traits0 aEcological stoichiometry drives the evolution of soil nematode l c02/2023 a1088910 v1773 a

Ecological stoichiometry is a useful theoretical framework for understanding the sources and controls on nutrient availability that structure the composition and diversity of biotic communities. One such relationship is that organismal development rate is positively linked to cellular Phosphorus (P). We hypothesized that P availability, relative to other nutrients, e.g., nitrogen and carbon, would drive the evolution of traits associated with organismal growth and development. We examined the effects of P availability both in situ and in vitro, on free-living soil nematodes. We found that P-deficient environments produce predictable changes in the ecology and evolution of important life history traits. Our results identify altered rRNA gene copy number and subsequent changes in gene expression and protein synthesis as mechanisms by which P-deficiency influences these traits. These findings have important implications for explaining soil ecological and evolutionary patterns across multiple levels of organization, including the structure and functioning of organisms, populations, communities, and ecosystems.

10aelemental stoichiometry10agrowth rate hypothesis10alife history theory10amolecular evolution10anematoda10arRNA1 aXue, Xia1 aAdhikari, Bishwo, N.1 aBall, Becky1 aBarrett, John, E.1 aMiao, Jinxin1 aPerkes, Ammon1 aMartin, Mac1 aSimmons, Breana, L.1 aWall, Diana, H.1 aAdams, Byron uhttps://www.sciencedirect.com/science/article/pii/S0038071722003480