Long-distance dispersion

Miller (1989) is the question of how such an ancient organism has come to exist on a comparatively new oceanic island. Long-distance dispersal is an unlikely explanation for the present situation. Dispersal over shorter distances from island to island seems a reasonable possibility, with subsequent disappearance of many, or apparently all in the present case, of the intermediate stepping stones. Invocation of island hopping, after all, has many precedents. As Miller (1989) pointed out, obviously some vascular plant lineages have survived, some of which may have histories that reach back to the Antarctic flora. Needless to say, deep phylogenetic analyses would be helpful in addressing this question. 

It is likely sigifificant that L. glaberrima is self-compatible, whereas most other species of Lasthenia are self-incompatible. Long-distance dispersal of a single propagule of L. glaberrima would then have been sufficient to establish the species in Chile. It is, of course, entirely possible that propagules from one or another of the self-incompatible species could also have made the journey, but without a reproduc-tively compatible partner their fates were sealed. 

The biota of long-distance dispersal. IV. Genetic systems in the flora of oceanic... 

The genus Lupinus comprises several hundred more or less well-defined species, 12 in the Old World and the others in the New World of North, Central and South America. Sequence data indicate that New World lupins apparently derived from Old World species. Long distance dispersal from Old World origin seems to have led to the colonization of the Atlantic part of South America (clade with L. aureonitens, L. albescens and L. paragmrensis) and of North America (see Fig. 7.12a) (Kass and Wink, 1997b). 

Past range shifts were accomplished by seed dispersal 10-100 km beyond the species range limit. The frequency of long-distance dispersal events has not been adequately measured, but data show clearly that the average dispersal distance differs between species. Migration models will have to include species-specific dispersal parameters. 

Hymowitz et al. (1990), based upon cytogenetic studies, hypothesized that the disjunct allopolyploid distribution of G. tabacina and G. tomentella between Australia and the islands of the west-central Pacific region was due to long-distance dispersal by migrating shore birds. That hypothesis was verified by Doyle et al. (1990a, 1990b) who examined chloroplast DNA and histone H3-D polymorphism patterns within the G. tabacina polyploidy complex. 

Hymowitz, T R.J. Singh P.R Larkin. Long distance dispersal. The case for the allopolyploids Glycine tahacina Benth. and G. tomentella Hayata in the west-central pacific. Micronesica 1990, 23, 5-13. 

As a summary of the ideas expressed in the chapters of this book some main conclusions arise several distribution patterns are described and different processes are hypothesised to explain them. Long-distance dispersal is evidently possible, but it is not the rule, as other distribution patterns can be explained by other mechanisms, such as continental drift, stepping-stone migration and anthropogenic introduction. 

Reviews Microbiology 4,102-112. Moncalvo, J.M., Buchanan, P.K. (2008). Molecular evidence for long distance dispersal across the southern hemisphere in the Ganoderma applanatum-australe species complex (Basidiomycota). Mycological Research 112, 425-436. 

Genetic diversity of Pisolithus in New Zealand indicates multiple long-distance dispersal from Australia. New Phytologist 160,569-579. 

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