open access

https://hdl.handle.net/2115/82052

Spatiotemporal fluctuations in natural selection acting on the gall-parasitic aphid Tetraneura sorini

英語

partial least square regression

2016-07

Blackwell Publishing

Journal of Evolutionary Biology

29(7)

1423-1436

The measurement of the selection gradient is crucial for understanding the magnitude of selection acting directly on a trait and predicting the evolutionary trajectory of that trait. This study evaluated the selection gradient acting on the morphology of the gall-parasitic aphid Tetraneura sorini during the galling process and compared the strength among populations. Gall formers (first instars) frequently fight with conspecifics or heterospecifics for usurping incipient galls using their well-developed hind legs. First instars that successfully acquired galls were found within galls, whereas those that failed were found dead on leaf surfaces. Selection gradients were estimated using logistic stepwise regression and partial least square (PLS) regression. Calculated selection differentials indicated that first instars that secured galls were larger in body size than failed individuals through all populations. However, selection gradients on weapon traits varied largely among populations or among years in the same population. We confirmed microevolutionary changes in the relationship between traits, which accorded with the expectation from changes in the selection gradients. When gall formers were transferred onto developing buds individually, individuals that successfully induced galls had smaller body size than failed individuals. Available evidence suggests that the selection gradient on body size becomes higher with an increasing proportion of T. sorini in the Tetraneura species community. Thus, we concluded that more intense fighting with conspecifics leads to stronger selective pressure on body size, but that selective pressure for each trait is variable depending on differences in the tactics and species composition among populations.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: Muramatsu, K. and Akimoto, S. (2016), Spatiotemporal fluctuations in natural selection acting on the gall-parasitic aphid Tetraneura sorini. J. Evol. Biol., 29: 1423-1436, which has been published in final form at https://doi.org/10.1111/jeb.12881. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

1010-061X