Ongoing climate change affects various aspects of an animal's life, with impor- tant effects on distribution range and phenology. The relationship between global warming and body size changes in mammals and birds has...Ongoing climate change affects various aspects of an animal's life, with impor- tant effects on distribution range and phenology. The relationship between global warming and body size changes in mammals and birds has been widely studied, with most find- ings indicating a decline in body size over time. Nevertheless, little data exist on similar size change patterns of invertebrates in general and insects in particular, and it is unclear whether insects should decrease in size or not with climate warming. We measured over 4000 beetle specimens, belonging to 29 beetle species in 8 families, collected in Israel during the last 100 years. The sampled species are all herbivorous. We examined whether beetle body size had changed over the years, while also investigating the relationships between body size and annual temperature, precipitation, net primary productivity (NPP) at the collection site and collection month. None of the environmental variables, including the collection year, was correlated with the size of most of the studied beetle species, while there were strong interactions of all variables with species. Our results, though mostly neg- ative, suggest that the effect of climate change on insect body size is species-specific and by no means a general macro-ecological rule. They also suggest that the intrapopulation variance in body size of insects collected as adults in the field is large enough to conceal intersite environmental effects on body size, such as the effect of temperature and NPE展开更多
The fauna of the Pleistocene Homo-bearing sites of Java has been well known for more than a century.A recent revision of the crocodylian remains confirmed both the validity of Gavialis bengawanicus and the synonymiza-...The fauna of the Pleistocene Homo-bearing sites of Java has been well known for more than a century.A recent revision of the crocodylian remains confirmed both the validity of Gavialis bengawanicus and the synonymiza-tion of Crocodylus ossifragus with C.siamensis.Here we report on a still unpublished crocodylian specimen collected by Eugene Dubois in the latest Early Pleistocene of Kali Gedeh that can be tentatively referred to the genus Crocodylus.The size of the specimen,the approximately 1 m long lower jaw in particular,indicat-ed that this crocodile attained a total length of approximately 6 or 7 m.Along with specimens from the Plio-Pleistocene of Africa,this material provides evidence for gigantism in Crocodylus.It is not clear whether or not the‘temperature-size rule’applies to fossil crocodylians,but due to the growing interest in predicting future temperature-related size changes of the extant organisms,it would be interesting to study in detail the past reac-tion to temperature changes of crocodylians and other terrestrial ectothermic animals.展开更多
文摘Ongoing climate change affects various aspects of an animal's life, with impor- tant effects on distribution range and phenology. The relationship between global warming and body size changes in mammals and birds has been widely studied, with most find- ings indicating a decline in body size over time. Nevertheless, little data exist on similar size change patterns of invertebrates in general and insects in particular, and it is unclear whether insects should decrease in size or not with climate warming. We measured over 4000 beetle specimens, belonging to 29 beetle species in 8 families, collected in Israel during the last 100 years. The sampled species are all herbivorous. We examined whether beetle body size had changed over the years, while also investigating the relationships between body size and annual temperature, precipitation, net primary productivity (NPP) at the collection site and collection month. None of the environmental variables, including the collection year, was correlated with the size of most of the studied beetle species, while there were strong interactions of all variables with species. Our results, though mostly neg- ative, suggest that the effect of climate change on insect body size is species-specific and by no means a general macro-ecological rule. They also suggest that the intrapopulation variance in body size of insects collected as adults in the field is large enough to conceal intersite environmental effects on body size, such as the effect of temperature and NPE
基金This research has been supported by Fondi ex-60%Universitàdi Torino(to M.Delfino)by the Ministerio de Economía y Com-petitividad de España(CGL2011-28681 to M.Delfino).
文摘The fauna of the Pleistocene Homo-bearing sites of Java has been well known for more than a century.A recent revision of the crocodylian remains confirmed both the validity of Gavialis bengawanicus and the synonymiza-tion of Crocodylus ossifragus with C.siamensis.Here we report on a still unpublished crocodylian specimen collected by Eugene Dubois in the latest Early Pleistocene of Kali Gedeh that can be tentatively referred to the genus Crocodylus.The size of the specimen,the approximately 1 m long lower jaw in particular,indicat-ed that this crocodile attained a total length of approximately 6 or 7 m.Along with specimens from the Plio-Pleistocene of Africa,this material provides evidence for gigantism in Crocodylus.It is not clear whether or not the‘temperature-size rule’applies to fossil crocodylians,but due to the growing interest in predicting future temperature-related size changes of the extant organisms,it would be interesting to study in detail the past reac-tion to temperature changes of crocodylians and other terrestrial ectothermic animals.