Spatial analysis of taxonomic and genetic patterns and their potential for understanding evolutionary histories Bickford, S en_US Laffan, Shawn en_US Kok, R en_US Orthia, L en_US 2021-11-25T13:09:52Z 2021-11-25T13:09:52Z 2004 en_US
dc.description.abstract Aim: The aim of this research is to develop and investigate methods for the spatial analysis of diversity based on genetic and taxonomic units of difference. We use monophyletic groups of species to assess the potential for these diversity indices to elucidate the geographical components of macro-scaled evolutionary processes. Location: The range occupied by Pultenaea species in temperate and sub-tropical eastern Australia, extending from western South Australia (133 degrees E - 32 degrees S) to Tasmania (146 degrees E - 43 degrees S) to coastal central Queensland (148 degrees E - 20 degrees S). Methods: We applied a series of both spatially explicit and spatially implicit analyses to explore the nature of diversity patterns in the genus Pultenaea, Fabaceae. We first analysed the eastern species as a whole and then the phylogenetic groups within them. We delineated patterns of endemism and biotic (taxon) regions that have been traditionally circumscribed in biogeographical studies of taxa. Centres of endemism were calculated using corrected weighted endemism at a range of spatial scales. Biotic regions were defined by comparing the similarity of species assemblages of grid cells using the Jaccard index and clustering similar cells using hierarchical clustering. On the basis that genetically coherent areas were likely to be more evolutionary informative than species patterns, genetic indices of similarity and difference were derived. A matrix of similarity distances between taxa was generated based on the number of shared informative characters of two sections of trnL-F and ndhF chloroplast nuclear regions. To identify genetically similar areas, we clustered cells using the mean genetic similarities of the species contained within each pair of cells. Measures of the mean genetic similarity of species in areas were delineated using a geographically local multi-scalar approach. Resultant patterns of genetic diversity are interpreted in relation to theories of the evolutionary relationships between species and species groups. Results: Centres of Pultenaea endemism were defined, those of clades 1 congruent with the spatially separated centres of clades 2 and 3. The taxonomic classification analysis defined cells with shared groups of species, which in some cases clustered when plotted in geographic space, defining biotic regions. In some instances the distribution of biotic regions was congruent with centres of endemism, however larger scale groupings were also apparent. In clade 1 one set of species was replaced by another along the extent of the range, with some connectivity between some geographically disjunct regions due to the presence of widespread species. In the combined analysis of clade 2 and 3 species the major biotic (taxonomic) groups with geographic coherence were defined by species in the respective clades, representing the geographic separation of these clades. However distinctive biotic regions within these main groupings of clades 2 and 3 were also apparent. Clustering cells using the mean genetic similarities of the species contained within each pair of cells indicated that some of the taxonomically defined biotic boundaries were the result of changes in composition of closely related species. This was most apparent in clades 1 and 2 where most cells were highly genetically similar. In clade 3 genetically distinct groups remained and were in part defined by sister taxa with disjunct distributions. Gradients in mean genetic similarity became more apparent from small to larger scales of analysis. At larger scales of analysis, regions of different levels of genetic diversity were delineated. Regions with highest diversity levels (lowest level of similarity) often represented regions where the ranges of phylogenetically distinctive species intergraded. Main conclusions: The combined analysis of diversity, phylogeny and geography has potential to reveal macro-scaled evolutionary patterns from which evolutionary processes may be inferred. The spatial genetic diversity indices developed in this study contribute new methods for identifying coherent evolutionary units in the landscape, which overcome some of the limitations of using taxonomic data, and from which the role of geography in evolutionary processes can be tested. We also conclude that a multiple-index approach to diversity pattern analysis is useful, especially where patterns may be the result of a long history of different environmental changes and related evolutionary events. The analysis contributes to the knowledge of large-scale diversity patterns of Pultenaea which has relevance for the assessment of the conservation status of the genus. en_US
dc.identifier.issn 0305-0270 en_US
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri en_US
dc.source Legacy MARC en_US
dc.subject.other spatial analysis en_US
dc.subject.other diversity pattern en_US
dc.subject.other species diversity en_US
dc.subject.other genetic diversity en_US
dc.subject.other endemism en_US
dc.subject.other biotic elements en_US
dc.subject.other macro-evolutionary processes en_US
dc.subject.other Pultenaea en_US
dc.title Spatial analysis of taxonomic and genetic patterns and their potential for understanding evolutionary histories en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.identifier.doiPublisher en_US
unsw.relation.faculty Science
unsw.relation.ispartofissue 11 en_US
unsw.relation.ispartofjournal Journal of Biogeography en_US
unsw.relation.ispartofpagefrompageto 1715-1733 en_US
unsw.relation.ispartofvolume 31 en_US
unsw.relation.originalPublicationAffiliation Bickford, S en_US
unsw.relation.originalPublicationAffiliation Laffan, Shawn, Biological, Earth & Environmental Sciences, Faculty of Science, UNSW en_US
unsw.relation.originalPublicationAffiliation Kok, R en_US
unsw.relation.originalPublicationAffiliation Orthia, L en_US School of Biological, Earth & Environmental Sciences *
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