Hans Peter Linder

Bio: Hans Peter Linder is an academic researcher from University of Zurich. The author has contributed to research in topics: Restionaceae & Species richness. The author has an hindex of 38, co-authored 107 publications receiving 6083 citations. Previous affiliations of Hans Peter Linder include University of Cape Town & Royal Botanic Gardens.

Phylogeny and subfamilial classification of the grasses (Poaceae)

Abstract: A large collaborative effort has yiel(led a comprehensive study of the phylogeny and a new suhfanilial classification of the grass family (Poaceae/Graminieae). The stu(ly was (con(luc(ted on an integratedl andl representative set of 62 grasses (0.6% of the species and ca. 8% of the genera) plus four outgroup taxa using six molecular sequence (lata sets ({ndhFl, rbcL, rpoC2, phyB, ITS2, and (;BSSI or waxy), chloroplast restriction site (lata, and( morphological idata. A parsimony analysis using 2143 informative characters (the comblined analysis) resulted in a single most parsimonious tree of 8752 steps with an RI of 0.556 and bootstrap support of > 90% for more than half of the internal no(les. Significant relationships that appear consistently in all analyses of all (lata sets and are strongly supported by the combined analysis include the following: Joinvilleaceae are sister to a monophyletic Poaceae; the earliest (liverging lineages of the Poaceae are Anomochlooideae, Pharoideae, and Puelioideae, respectively; and( all remaining grasses form a clade. Multiple monophyletic clades were recovere(, including Bambusoideae s. str., Ehrhartoideae, Pooideae s.l., Aristidoideae, l)anthonioideae, Chloridoideae s. str., Chloridoideae s.l., Panicoideae, Parianeae, Olyreae s. str., Oryzeae, Stipeae, Meliceae, Lygeum + Nardus, and Molinia + Phragmites. 'The PACCAI) Clade is monophyletic, containing Aristidoideae, Danthonioideae, Arundinoideae s. str., Chloridoideae s.l., Centothecoideae, Panicoideae, Eriachne, Micraira, and Gynerium. Based on the phylogeny, a classification of 11 previously published subfamilies (Anomochlooideae, Pharoideae, Puelioideae, Bambusoideae, Ehrhartoideae, Pooideae, Aristidoideae, Arundinoideae, Chloridoideae, Centothecoideae, and Panicoideae) and 1 new subfamily (Danthonioideae) is proposed. Several changes in the circumscription of traditionally recognized subfamilies are included. Previous phylogenetic work and classifications are reviewed in relation to this classification and circumscription, and major characteristics of each subfamily are discussed and described. The matrix, trees, and updated data matrix are available at (http://www.virtualherbarium.org/grass/gpwg/ default.htm).

Endemism in the Australian flora

Abstract: Aim To detect centres of vascular plant endemism at a continental scale by analysis of specimen-based distributional data and to relate any pattern to environmental factors and history. Location Australia. Methods Presence of 8468 seed plant species-level taxa throughout continental Australia and Tasmania was mapped on a 1∞ grid to visualize the pattern of species richness. This sample comprises half the known flora. Three indices of endemism were calculated but we preferred one that is unrelated to species richness, so that these two concepts could be distinguished in practice. Centres of endemism were detected by simple mapping and by spatial autocorrelation analysis (SAC). Linear regression was used to examine the relationship of the patterns of species richness and endemism to latitude, topography and climate. Results Both species richness and endemism vary greatly across the continent but in most cases the same centres were high in both richness and endemism. Twelve distinct centres were identified. The major centres of both diversity and endemism are south-west western Australia, the Border Ranges between New South Wales and Queensland, the Wet Tropics near Cairns, Tasmania and the Iron-McIlwraith Range of eastern Cape York Peninsula. The last centre appears to be more significant than recognized by past authors. Whether this is a true Australian centre of endemism, or is largely an outlier of the flora of Papua New Guinea, is explored. Another centre, in the Adelaide‐Kangaroo Island region, has been overlooked altogether by previous authors. Regression analysis did not find a simple climatic explanation of the observed patterns. There was a suggestion that topographic variation within the 1∞ cells may be positively correlated with endemism, which is consistent with mountainous regions functioning as refugia. One clear result is that all the major centres of endemism are near-coastal. A likely explanation is that Pleistocene expansions of the central desert have been a powerful limitation on the viability of refugia for narrowly endemic species. All the centres of endemism lie outside the estimated limits of the expanded arid zone at the last glacial maximum (18,000 yr BP). In particular, the ‘Central Australian Mountain Ranges centre of plant diversity and endemism’ of Boden & Given (1995) is detected as a strong centre of species richness, but not at all as a centre of endemism. This is despite good sampling of this region. Main conclusions Endemism can be distinguished from species richness by using an appropriate index and mapping of such indices can detect centres of endemism. This study demonstrates the value of specimen based distributional data, such as is held in state herbaria and museums.

The radiation of the Cape flora, southern Africa

Abstract: The flora of the south-western tip of southern Africa, the Cape flora, with some 9000 species in an area of 90,000 km2 is much more speciose than can be expected from its area or latitude, and is comparable to that expected from the most diverse equatorial areas. The endemism of almost 70%, on the other hand, is comparable to that found on islands. This high endemism is accounted for by the ecological and geographical isolation of the Cape Floristic Region, but explanations for the high species richness are not so easily found. The high species richness is accentuated when its taxonomic distribution is investigated: almost half of the total species richness of the area is accounted for by 33 'Cape floral clades'. These are clades which may have initially diversified in the region, and of which at least half the species are still found in the Cape Floristic Region. Such a high contribution by a very small number of clades is typical of island floras, not of mainland floras. The start of the radiation of these clades has been dated by molecular clock techniques to between 18 million years ago (Mya) (Pelargonium) and 8 Mya (Phylica), but only six radiations have been dated to date. The fossil evidence for the dating of the radiation is shown to be largely speculative. The Cenozoic environmental history of southern Africa is reviewed in search of possible triggers for the radiations, climatic changes emerge as the most likely candidate. Due to a very poor fossil record, the climatic history has to be inferred from larger scale patterns, these suggest large-scale fluctuations between summer wet (Palaeocene, Early Miocene) and summer dry climates (Oligocene, Middle Miocene to present). The massive speciation in the Cape flora might be accounted for by the diverse limitations to gene flow (dissected landscapes, pollinator specialisation, long flowering times allowing much phenological specialisation), as well as a richly complex environment providing a diversity of selective forces (geographically variable climate, much altitude variation, different soil types, rocky terrain providing many micro-niches, and regular fires providing both intermediate disturbances, as well as different ways of surviving the fires). However, much of this is based on correlation, and there is a great need for (a) experimental testing of the proposed speciation mechanisms, (b) more molecular clock estimates of the age and pattern of the radiations, and (c) more fossil evidence bearing on the past climates.

Plant diversity and endemism in sub‐Saharan tropical Africa

Abstract: Aim This paper has as its central aim the location of centres of species richness and endemism in the sub-Saharan African flora. Previous postulation of these centres has been based on an intuitive interpretation of distributional data; this paper provides a test of these centres. A second aim is to establish whether the two indices, richness and endemism, locate the same centres. Thirdly the relationship between species richness and endemism, and latitude and rainfall are explored. Location The study area includes much of sub-Saharan Africa, but excludes the species-poor southern margin of the Sahara and the Namib–Kalahari regions. Methods Analyses were based on 1818 species, scored on a 2.5 × 2.5 degree grid. Species richness was inferred from a simple grid-diversity count; endemism was determined by three measures: the number of species restricted to two grids, the sum of the inverse of the ranges of the component species of each grid, and the proportion of the species in each grid that have restricted ranges. Results The African flora shows a remarkably profound patterning, both in species richness and endemism. The two measures locate largely the same centres, although the rank order among them differs. These centres are: the Cape Floristic Region, East Coast, Congo-Zambezi watershed, Kivu, Upper and Lower Guinea. Richness is strongly related to maximum rainfall, but there are no obvious correlations between modern climate and endemism. Species richness and endemism north of the equator is much more concentrated into centres than south of the equator. Main conclusions There are strongly developed refugia in sub-Saharan Africa. North of the equator, these refugia are sharply delimited and rather small, separated by large areas of very low endemism. South of the equator endemism tends to be more generally distributed. Variation in species richness in sub-Saharan Africa can be explained largely by modern rainfall, while endemism may be related to palaeoclimatic fluctuations. Both species richness and endemism show a strong skewing towards the south, indicating that the fluctuations in the Sahara might have influenced the modern distribution of plants in Africa.

Phylogeny and radiation of pollination systems in DISA (Orchidaceae).

Abstract: We studied the patterns of adaptive radiation in Disa, a large orchid genus in southern Africa. A cladogram for 27 species was constructed using 44 morphological characters. Pollination systems were then mapped onto the phylogeny in order to analyze pathways of floral evolution. Shifts from one pollination system to another have been a major feature of the evolutionary diversification of Disa. Unlike many plant genera that are pollinated mainly by a single group of insects, radiation in Disa has encompassed nearly all major groups of pollinating insects; in all, 19 different specialized pollination systems have been found in the 27 species included in this analysis. Another striking pattern is the repeated evolution of broadly similar pollination systems in unrelated clades. For example, butterfly-pollinated flowers have evolved twice; showy deceptive flowers pollinated by carpenter bees, twice; long-spurred flowers pollinated by long-tongued flies, four times; night-scented flowers pollinated by moths, three times; and self-pollination, three times. This suggests that a few dominant pollinator species in a region may be sufficient to generate diversification in plants through repeated floral shifts that never retrace the same pathways.

The Theory of Island Biogeography

Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

Analysis of the genome sequence of the flowering plant Arabidopsis thaliana.

Abstract: The flowering plant Arabidopsis thaliana is an important model system for identifying genes and determining their functions. Here we report the analysis of the genomic sequence of Arabidopsis. The sequenced regions cover 115.4 megabases of the 125-megabase genome and extend into centromeric regions. The evolution of Arabidopsis involved a whole-genome duplication, followed by subsequent gene loss and extensive local gene duplications, giving rise to a dynamic genome enriched by lateral gene transfer from a cyanobacterial-like ancestor of the plastid. The genome contains 25,498 genes encoding proteins from 11,000 families, similar to the functional diversity of Drosophila and Caenorhabditis elegans--the other sequenced multicellular eukaryotes. Arabidopsis has many families of new proteins but also lacks several common protein families, indicating that the sets of common proteins have undergone differential expansion and contraction in the three multicellular eukaryotes. This is the first complete genome sequence of a plant and provides the foundations for more comprehensive comparison of conserved processes in all eukaryotes, identifying a wide range of plant-specific gene functions and establishing rapid systematic ways to identify genes for crop improvement.

The vegetation of South Africa, Lesotho and Swaziland.

Abstract: The plant genus Strelitzia occurs naturally in the eastern parts of southern Africa. It comprises three arborescent species, known as wild bananas, and two acaulescent species, known as crane flowers or bird-of-paradise flowers. The logo of the South African National Biodiversity Institute is based on the striking inflorescence of Strelitzia reginae, a native of the Eastern Cape and KwaZulu-Natal that has become a garden favourite worldwide. It symbolises the commitment of the Institute to promote the sustainable use, conservation, appreciation and enjoyment of the exceptionally rich biodiversity of South Africa, for the benefit of all people.

The global diversity of birds in space and time

Abstract: Current global patterns of biodiversity result from processes that operate over both space and time and thus require an integrated macroecological and macroevolutionary perspective. Molecular time trees have advanced our understanding of the tempo and mode of diversification and have identified remarkable adaptive radiations across the tree of life. However, incomplete joint phylogenetic and geographic sampling has limited broad-scale inference. Thus, the relative prevalence of rapid radiations and the importance of their geographic settings in shaping global biodiversity patterns remain unclear. Here we present, analyse and map the first complete dated phylogeny of all 9,993 extant species of birds, a widely studied group showing many unique adaptations. We find that birds have undergone a strong increase in diversification rate from about 50 million years ago to the near present. This acceleration is due to a number of significant rate increases, both within songbirds and within other young and mostly temperate radiations including the waterfowl, gulls and woodpeckers. Importantly, species characterized with very high past diversification rates are interspersed throughout the avian tree and across geographic space. Geographically, the major differences in diversification rates are hemispheric rather than latitudinal, with bird assemblages in Asia, North America and southern South America containing a disproportionate number of species from recent rapid radiations. The contribution of rapidly radiating lineages to both temporal diversification dynamics and spatial distributions of species diversity illustrates the benefits of an inclusive geographical and taxonomical perspective. Overall, whereas constituent clades may exhibit slowdowns, the adaptive zone into which modern birds have diversified since the Cretaceous may still offer opportunities for diversification.

Pollination Syndromes and Floral Specialization

Abstract: ▪ Abstract Floral evolution has often been associated with differences in pollination syndromes. Recently, this conceptual structure has been criticized on the grounds that flowers attract a broader spectrum of visitors than one might expect based on their syndromes and that flowers often diverge without excluding one type of pollinator in favor of another. Despite these criticisms, we show that pollination syndromes provide great utility in understanding the mechanisms of floral diversification. Our conclusions are based on the importance of organizing pollinators into functional groups according to presumed similarities in the selection pressures they exert. Furthermore, functional groups vary widely in their effectiveness as pollinators for particular plant species. Thus, although a plant may be visited by several functional groups, the relative selective pressures they exert will likely be very different. We discuss various methods of documenting selection on floral traits. Our review of the literatur...