Universal sublinear population growth density dependence unrelated to resource limitation

Mazzarisi, O.; Droghetti, R.; Carmichael, H.; Ciandrini, L.; Cosentino Lagomarsino, M.; Dal Bello, M.; Fant, L.; Ghedini, G.; Grilli, J.; Yvon-Durocher, G.; Reuman, D. C.

doi:10.64898/2025.12.30.697033

bioRxiv · 10.64898/2025.12.30.697033

Universal sublinear population growth density dependence unrelated to resource limitation

Mazzarisi, O.·Droghetti, R.·Carmichael, H.·Ciandrini, L.·Cosentino Lagomarsino, M.·Dal Bello, M.·Fant, L.·Ghedini, G.·Grilli, J.·Yvon-Durocher, G.·Reuman, D. C.

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Abstract

Growth slows as population density increases, sensitively influencing species coexistence, conservation, and resource management. This slowdown is widely attributed to declining per-capita access to energy and nutrients, and standard models of resource-limited growth predict superlinear declines of growth rate with density. However, we observed sublinear declines for 94% of 4,022 bacterial and eukaryotic growth curves. High-resolution experiments with Escherichia coli revealed a two-phase density dependence: a dominant sublinear regime that transitions to superlinear decline only very near population saturation. The sublinear pattern was invariant across initial resource concentrations, ruling out resource depletion as the cause of early slowing. Our results challenge the standard resource-limitation paradigm and identify non-resource inhibitory processes as a widespread and previously unappreciated regulator of population growth.

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Mazzarisi, O., Droghetti, R., Carmichael, H., Ciandrini, L., Cosentino Lagomarsino, M., Dal Bello, M., Fant, L., Ghedini, G., Grilli, J., Yvon-Durocher, G., Reuman, D. C.. 2025-12-30. Universal sublinear population growth density dependence unrelated to resource limitation. https://doi.org/10.64898/2025.12.30.697033

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