Protandry (prior emergence of males) in insect populations is usually considered to be the result of natural selection acting directly on eclosion timing. When females are monandrous (mate once), males in high density populations benefit from early emergence in the intense scramble competition for mates. In low density populations, however, scramble competition is reduced or absent, and theoret...

Our possibility to appropriately detect, interpret and respond to climate-driven phenological changes depends on our ability to model and predict the changes. This ability may be hampered by non-linearity in climate-phenological relations, and by spatiotemporal variability and scale mismatches of climate and phenological data. A modeling methodology capable of handling such complexities can be ...

Metapopulation theory provides a framework for understanding population persistence in fragmented landscapes and as such has been widely used in conservation biology to inform management of fragmented populations. However, classical metapopulation theory [Levins, R. (1970) Lect. Notes Math. 2, 75-107] ignores metapopulation structure and local population dynamics, both of which may affect extin...

This chapter surveys the fundamental forces that drive the formation and size of cities. We discuss the different types of agglomeration economies generated by a dense web of activities, with special emphasis on the benefits associated with the clustering of highly skilled workers. The distribution of activities within cities results from the trade-off between commuting and housing costs. We sh...

The nucleotide sequences of 5S rRNA from two red algae, Gracilaria compressa and Porphyra tenera have been determined. The two 5S rRNAs are fairly dissimilar to each other in their sequences (65% identity), although they are both composed of 121 nucleotides. Their secondary structures are generally of the eukaryotic with a prokaryotic characteristic. Judged from the 5S rRNA sequence data, the r...

The changes in diatom species composition in a sediment core from Crevice Lake, Yellowstone National Park, spanning the past 2550 yr, were used to reconstruct long-term limnological and ecological conditions that may be related to late Holocene climate variability. Planktic forms dominate the fossil diatom assemblages throughout this record, but changes in species dominance indicate varying nut...