Phylogeographic analysis of North American populations of the parasitic herbaceous plant Monotropa hypopitys reveals a complex history of range expansion from multiple late glacial refugia

Aim We carried out a phylogeographic study across the range of the herbaceous plant species Monotropa hypopitys L. in North America to determine whether its current disjunct distribution is due to recolonization from separate eastern and western refugia after the Last Glacial Maximum (LGM). Location North America: Pacific Northwest and north-eastern USA/south-eastern Canada. Methods Palaeodistribution modelling was carried out to determine suitable climatic regions for M. hypopitys at the LGM. We analysed between 155 and 176 individuals from 39 locations spanning the species' entire range in North America. Sequence data were obtained for the chloroplast rps2 gene (n=168) and for the nuclear ITS region (n=158). Individuals were also genotyped for eight microsatellite loci (n=176). Interpolation of diversity values was used to visualize the range-wide distribution of genetic diversity for each of the three marker classes. Minimum spanning networks were constructed showing the relationships between the rps2 and ITS haplotypes, and the geographical distributions of these haplotypes were plotted. The numbers of genetic clusters based on the microsatellite data were estimated using Bayesian clustering approaches. Results The palaeodistribution modelling indicated suitable climate envelopes for M. hypopitys at the LGM in both the Pacific Northwest and south-eastern USA. High levels of genetic diversity and endemic haplotypes were found in Oregon, the Alexander Archipelago, Wisconsin, and in the south-eastern part of the species' distribution range. Main conclusions Our results suggest a complex recolonization history for M. hypopitys in North America, involving persistence in separate eastern and western refugia. A generally high degree of congruence between the different marker classes analysed indicated the presence of multiple refugia, with at least two refugia in each area. In the west, putative refugia were identified in Oregon and the Alexander Archipelago, whereas eastern refugia may have been located in the southern part of the species' current distribution, as well as in the 'Driftless Area'. These findings are in contrast to a previous study on the related species Orthilia secunda, which has a similar disjunct distribution to M. hypopitys, but which appears to have recolonized solely from western refugia. © 2011 Blackwell Publishing Ltd.

Adolescent men's attitudes and decision-making in relation to an unplanned pregnancy. Responses to an interactive video drama

This study confronts a gender bias in research on adolescent pregnancy by exploring adolescent men’s decisions relating to a hypothetical unplanned pregnancy. A cross-sectional survey was conducted with adolescent men (N = 360) aged between 14 and 18 years attending schools in the Republic of Ireland. The study, the first of its kind in Europe, extends the small body of evidence on adolescent men and pregnancy decision-making by developing and examining reactions to an interactive video drama used in a comparable study in Australia. In addition, we tested a more comprehensive range of sociological and psychological determinants of adolescent men’s decisions regarding an unplanned pregnancy. Results showed that adolescent men were more likely to choose to keep the baby in preference to abortion or adoption. Adolescent men’s choice to continue the pregnancy (keep or adopt) in preference to abortion was significantly associated with anticipated feelings of regret in relation to abortion, perceived positive attitudes of own mother to keeping the baby and a feeling that a part of them might want a baby. Religiosity was also shown to underlie adolescent men’s views on the perceived consequences of an abortion in their lives.