In North-western Iceland, records of slope processes were increasing during the twentieth century. Few dramatic events during the last decades highlighted the danger due to slope dynamics, leaving local populations in a risk situation that was merely unknown before 1970. The recent snow-avalanche, debris-flow and rock-fall activity underlined that the most frequent processes are not these with ...

The regular cyclic fluctuations in vertebrate numbers have intrigued scientists for more than 70 years, and yet the cause of such cycles has not been clearly demonstrated. Red grouse populations in Britain exhibit cyclic fluctuations in abundance, with periodic crashes. The hypothesis that these fluctuations are caused by the impact of a nematode parasite on host fecundity was tested by experim...

Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless fa...