TY - JOUR
T1 - Life history traits, but not body size, vary systematically along latitudinal gradients on three continents in the widespread yellow dung fly
AU - Blanckenhorn, Wolf U.
AU - Bauerfeind, Stephanie S.
AU - Berger, David
AU - Davidowitz, Goggy
AU - Fox, Charles W.
AU - Guillaume, Frédéric
AU - Nakamura, Satoshi
AU - Nishimura, Kinya
AU - Sasaki, Hitoshi
AU - Stillwell, R. Craig
AU - Tachi, Takuji
AU - Schäfer, Martin A.
N1 - Funding Information:
Acknowledgements – We thank many people who have contributed to this long-term project, especially the numerous fly collectors listed in Supplementary material Appendix 1 Table A1. Funding – This work was supported by grant 3100A0-111775 from the Swiss National Foundation and several other grants over the years, the Zoological Museum Zurich, and the Univ. of Zurich. The JSPS funded an extended visit of WUB to Japan to complete the project. Author contributions – WUB and MAS conceived and lead the research. They plus SSB, DB, RCS, GD, and CWF performed the rearing in Zürich or the USA. GD, SSB and CWF coordinated the field collections in North America. SN coordinated WUB’s sabbatical visit and the field collections in Japan together with KN, HS and TT. WUB, CWF and MAS analysed the data, FG performed the Fst/Qst analyses. WUB, MAS and CWF wrote the paper, with input by all others. All authors have seen and agreed to the submission and publication of this manuscript.
Publisher Copyright:
© 2018 The Authors
PY - 2018/12
Y1 - 2018/12
N2 - Large-scale clinal variation in body size and other life-history traits is common enough to have stimulated the postulation of several eco-geographical rules. Whereas some clinal patterns are clearly adaptive, the causes of others remain unclear. We present a comprehensive intraspecific population comparison for the cosmopolitan yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) to check for consistent world-wide patterns. Common garden assessment of various life history traits permitted continental comparison of (clinal) quantitative genetic differentiation (Qst) with putatively neutral genetic differentiation (Fst) derived from field-caught flies. Latitudinal clines in fly development time, growth rate, and overwintering propensity were consistent among North American, European and Japanese populations. Increased winter dormancy incidence and duration at higher latitude, combined with a faster growth rate and shorter development time, suggest that flies are adaptated to season length more than to temperature. The resulting body size clines, in contrast, were not very consistent; importantly, they were not negative, as expected under seasonal constraints, but flat or even positive clines. Quantitative genetic differentiation QST exceeded neutral molecular variation FST for most traits, suggesting that natural selection plays a consistent role in mediating global dung fly life histories. We conclude that faster growth and development in response to shorter growing seasons at higher latitudes may indirectly counteract expected direct effects of temperature on body-size, potentially resulting in flat or inconsistent body size clines in nature.
AB - Large-scale clinal variation in body size and other life-history traits is common enough to have stimulated the postulation of several eco-geographical rules. Whereas some clinal patterns are clearly adaptive, the causes of others remain unclear. We present a comprehensive intraspecific population comparison for the cosmopolitan yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) to check for consistent world-wide patterns. Common garden assessment of various life history traits permitted continental comparison of (clinal) quantitative genetic differentiation (Qst) with putatively neutral genetic differentiation (Fst) derived from field-caught flies. Latitudinal clines in fly development time, growth rate, and overwintering propensity were consistent among North American, European and Japanese populations. Increased winter dormancy incidence and duration at higher latitude, combined with a faster growth rate and shorter development time, suggest that flies are adaptated to season length more than to temperature. The resulting body size clines, in contrast, were not very consistent; importantly, they were not negative, as expected under seasonal constraints, but flat or even positive clines. Quantitative genetic differentiation QST exceeded neutral molecular variation FST for most traits, suggesting that natural selection plays a consistent role in mediating global dung fly life histories. We conclude that faster growth and development in response to shorter growing seasons at higher latitudes may indirectly counteract expected direct effects of temperature on body-size, potentially resulting in flat or inconsistent body size clines in nature.
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U2 - 10.1111/ecog.03752
DO - 10.1111/ecog.03752
M3 - Article
AN - SCOPUS:85050360868
SN - 0906-7590
VL - 41
SP - 2080
EP - 2091
JO - Ecography
JF - Ecography
IS - 12
ER -