Temperature and humidity are among the most important environmental factors affecting insect adaptive strategies and evolution. Here, we report multiple adaptive differences between Drosophila melanogaster isofemale lines derived from the opposite slopes of Lower Nahal Oren canyon at Mount Carmel, Israel. The slopes are separated by 100 m at the bottom and 400 m at the top, and contrast sharply in physical and biotic factors. The multivariate fitness complex analysed in D. melanogaster included oviposition temperature preferences, viability and longevity changes, caused by short-term and lifetime temperature treatments, and resistance to drought stress at different temperatures. Some of these measures were obtained for the sibling species, D. simulans, and gave results that paralleled those of D. melanogaster. We conclude that strong microclimatic natural selection overrides migration in Drosophila at this microsite.
Bibliographical noteFunding Information:
The authors acknowledge with thanks the helpful comments and suggestions of two anonymous referees. This research was supported by the Israeli Ministry of Absorption, the Israeli Ministry of Science, grant no. 4147, the Ancell-Teicher Research Foundation for Genetics and Molecular Evolution and the Israel Discount Bank Chair of Evolutionary Biology.
- Drosophila melanogaster
- Habitat choice
- Heat stress
- Microsite selection
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