Abstract. A goal of phylogeography is to relate patterns of genetic differentiation to potential historical geographic isolating events. Quaternary glaciations, particularly the one culminating in the Last Glacial Maximum ;21 ka (thousands of years ago), greatly affected the distributions and population sizes of temperate marine species as their ranges retreated southward to escape ice sheets. Traditional genetic models of glacial refugia and routes of recolonization include these predictions: low genetic diversity in formerly glaciated areas, with a small number of alleles/haplotypes dominating disproportionately large areas, and high diversity including ''private'' alleles in glacial refugia. In the Northern Hemisphere, low diversity in the north and high diversity in the south are expected. This simple model does not account for the possibility of populations surviving in relatively small northern periglacial refugia. If these periglacial populations experienced extreme bottlenecks, they could have the low genetic diversity expected in recolonized areas with no refugia, but should have more endemic diversity (private alleles) than recently recolonized areas. This review examines evidence of putative glacial refugia for eight benthic marine taxa in the temperate North Atlantic. All data sets were reanalyzed to allow direct comparisons between geographic patterns of genetic diversity and distribution of particular clades and haplotypes including private alleles. We contend that for marine organisms the genetic signatures of northern periglacial and southern refugia can be distinguished from one another. There is evidence for several periglacial refugia in northern latitudes, giving credence to recent climatic reconstructions with less extensive glaciation.

Ulva, one of the first Linnaean genera, was later circumscribed to consist of green seaweeds with distromatic blades, and Enteromorpha Link was established for tubular forms. Although several lines of evidence suggest that these generic constructs are artificial, Ulva and Enteromorpha have been maintained as separate genera. Our aims were to determine phylogenetic relationships among taxa currently attributed to Ulva, Enteromorpl/(J, Umhraulva Bae et I.K. Lee and the monotypic genus Chloropelta C.E. Tanner. and to make any nomenclatural changes justified by our findings. Analyses of nuclear ribosomal internal transcribed spacer DNA (ITS nrDNA) (29 ingroup taxa including the type species of Ulm and Ellteromorpha), the chloroplast-encoded rbcL gene (for a subset of taxa) and a combined data set were carried out.

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Phylogeographic analysis of the red seaweed Palmaria palmata reveals a Pleistocene marine glacial refugium in the English Channel Provan, J., Maggs, C., & Wattier, R. A. (2005). Phylogeographic analysis of the red seaweed Palmaria palmata reveals a Pleistocene marine glacial refugium in the English Channel. Phylogeographic analysis of the red seaweed

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