The Last Glacial Maximum (LGM) refers to a period in the Earth's climate history when ice sheets were at their maximum extension, between 26,500 and 19,000–20,000 years ago,[1] marking the peak of the last glacial period. During this time, vast ice sheets covered much of North America, northern Europe and Asia. These ice sheets profoundly impacted Earth's climate, causing drought, desertification, and a dramatic drop in sea levels.[2] It was followed by the Late Glacial Maximum.
2. 末次冰期后，动植物在欧洲/美洲的扩张历史。
http://johnhawks.net/weblog/topics/population_structure/movement/postglacial-brown-bears-2009.html
Ursus It seems that each taxon has responded independently to Quaternary cold periods ,and therefore is largely a unique case with its own history .For example ,if we compare lineages present in Italy and in the Iberic peninsula ,they are closely related in (less than 1% of sequence divergence in the cytochrome bgene) but much more distantly related in Crocidura(6.4%), in Arvicola(7.6%) and in Triturus(8.5%), Sorexwhile the species considered here exhibit two lineages in each of these two refugia. Populations occurring in France come either from a refugium in the Iberic peninsula (e.g., Arvicola sapidus, Triturus marmoratus), or from a refugium in the Balkans (e.g., Chorthippus parallelus, Fagus sylvaticus).
...[T ]he results obtained in Europe and North America (Zink 1996)suggest that congruence is the exception at the continental scale .The consequence of an independent history for each taxon is that assemblages of plants and animals comprising particular communities are not stable over time ,an observation consistent with previous findings based mainly on fossil pollen data (Bennett 1990) (Taberlet et al . 1998:459).
3. Demographic History Has Influenced Nucleotide Diversity in European Pinus sylvestris Populations
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