CHILL-COMA TOLERANCE, A MAJOR CLIMATIC ADAPTATION AMONG DROSOPHILA SPECIES

• Published in: Evolution 2001-05, Vol.55 (5), p.1063-1068
• Main Authors: Gibert, Patricia, Moreteau, Brigitte, Pétavy, Georges, Karan, Dev, David, Jean R
• Format: Article
• Language: English
• Subjects: Acclimatization - physiology; Adaptation; Animals; Biological adaptation; Biological Evolution; Biological taxonomies; BRIEF COMMUNICATIONS; Chill coma; Chills; Climate; Climate models; climatic adaptation; Cold Climate; Cold tolerance; Coma; Coma - physiopathology; Drosophila; Drosophila - physiology; Drosophila melanogaster; Drosophila melanogaster - physiology; Experiments; Insect genetics; Insects; Life Sciences; Other; Phylogeny; Population genetics; Species; Species Specificity; Temperature; Time Factors; Tropical Climate; Tropical climates
• ISSN: 0014-3820; 1558-5646
• DOI: 10.1554/0014-3820(2001)055[1063:CCTAMC]2.0.CO;2

Most drosophilid species can be classified either as temperate or tropical. Adults of species were submitted to a cold treatment (0°C) and then brought back to ambient temperature. They generally exhibited a chill coma and the time needed to recover was measured. We found in a set of 26 temperate species that recovery was rapid (average 1.8 min, range 0.15–4.9). In contrast, a long recovery time (average 56 min, range 24–120) was observed for 48 tropical species. A few species, like Drosophila melanogaster, are cosmopolitan and can proliferate under temperate and tropical climates. In 9 of 10 such species, slight genetic differences were found: a shorter recovery in temperate than in tropical populations. Comparing physiological data to phylogeny suggests that chill-coma tolerance has been a recurrent adaptation that is selected for in cold climates but tends to disappear under a permanently warm environment. This major climatic adaptation, evidenced in drosophilids, seems to occur in other insect groups also. Corresponding Editor: T. Mousseau