Destabilized host-parasite dynamics in newly founded populations

Bolnick, D. I.; Barrett, R.; Choi, E.; Eckert, L.; Hendry, A.; Kerns, E. V.; Lind, A.; Milligan-McClellan, K.; Peichel, C.; Sasser, K. T.; Wolf, C.; Steinel, N.; Weber, J. N.

doi:10.1101/2024.06.24.600494

bioRxiv · 10.1101/2024.06.24.600494

Destabilized host-parasite dynamics in newly founded populations

Bolnick, D. I.·Barrett, R.·Choi, E.·Eckert, L.·Hendry, A.·Kerns, E. V.·Lind, A.·Milligan-McClellan, K.·Peichel, C.·Sasser, K. T.·Wolf, C.·Steinel, N.·Weber, J. N.

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Abstract

When species disperse into previously unoccupied habitats, new populations encounter unfamiliar species interactions such as altered parasite loads. Theory predicts that newly founded populations should exhibit destabilized eco-evolutionary fluctuations in infection rates and immune traits. However, to understand founder effects biologists typically rely on retrospective studies of range expansions, missing early-generation infection dynamics. To remedy this, we experimentally founded whole-lake populations of threespine stickleback. Infection rates were temporally stable in native source lakes. In contrast, newly founded populations exhibit destabilized host-parasite dynamics: high starting infection rates led to increases in a heritable immune trait (peritoneal fibrosis), suppressing infection rates. The resulting temporal auto-correlation between infection and immunity suggest that newly founded populations can exhibit rapid host-parasite eco-evolutionary dynamics.

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Bolnick, D. I., Barrett, R., Choi, E., Eckert, L., Hendry, A., Kerns, E. V., Lind, A., Milligan-McClellan, K., Peichel, C., Sasser, K. T., Wolf, C., Steinel, N., Weber, J. N.. 2024-06-27. Destabilized host-parasite dynamics in newly founded populations. https://doi.org/10.1101/2024.06.24.600494

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