02659nas a2200169 4500008004100000245015800041210006900199300000700268490000700275520206500282100001802347700002202365700001502387700001702402700002102419856004902440 2015 eng d00aOligocene niche shift, Miocene diversification - Cold tolerance and accelerated speciation rates in the St. John's Worts (Hypericum, Hypericaceae)0 aOligocene niche shift Miocene diversification Cold tolerance and a800 v503 a

Background: Our aim is to understand the evolution of species-rich plant groups that shifted from tropical into cold/temperate biomes. It is well known that climate affects evolutionary processes, such as how fast species diversify, species range shifts, and species distributions. Many plant lineages may have gone extinct in the Northern Hemisphere due to Late Eocene climate cooling, while some tropical lineages may have adapted to temperate conditions and radiated; the hyper-diverse and geographically widespread genus Hypericum is one of these.

Results: To investigate the effect of macroecological niche shifts on evolutionary success we combine historical biogeography with analyses of diversification dynamics and climatic niche shifts in a phylogenetic framework. Hypericum evolved cold tolerance c. 30 million years ago, and successfully colonized all ice-free continents, where today ~500 species exist. The other members of Hypericaceae stayed in their tropical habitats and evolved into ~120 species. We identified a 15–20 million year lag between the initial change in temperature preference in Hypericum and subsequent diversification rate shifts in the Miocene.

Conclusions: Contrary to the dramatic niche shift early in the evolution of Hypericum most extant species occur in temperate climates including high elevations in the tropics. These cold/temperate niches are a distinctive characteristic of Hypericum. We conclude that the initial release from an evolutionary constraint (from tropical to temperate climates) is an important novelty in Hypericum. However, the initial shift in the adaptive landscape into colder climates appears to be a precondition, and may not be directly related to increased diversification rates. Instead, subsequent events of mountain formation and further climate cooling may better explain distribution patterns and species-richness in Hypericum. These findings exemplify important macroevolutionary patterns of plant diversification during large-scale global climate change.

1 aNürk, N., M.1 aUribe-Convers, S.1 aGehrke, B.1 aTank, D., C.1 aBlattner, F., R. uhttp://www.biomedcentral.com/1471-2148/15/8002248nas a2200157 4500008004100000020001600041245010900057210006900166300000800235490000600243520163400249100002301883700002401906700002501930856013501955 2013 eng d a- 1664-802100aExplosive radiation in high Andean Hypericum– Rates of diversification among New World lineages0 aExplosive radiation in high Andean iHypericumi Rates of diversif a1750 v43 a

The páramos, high-elevation Andean grasslands ranging from ca. 2800m to the snow line, harbor one of the fastest evolving biomes worldwide since their appearance in the northern Andes 3–5 million years (Ma) ago. Hypericum (St. John’s wort), with over 65% of its Neotropical species, has a center of diversity in these high Mountain ecosystems. Using nuclear rDNA internal transcribed spacer (ITS) sequences of a broad sample of New World Hypericum species we investigate phylogenetic patterns, estimate divergence times, and provide the first insights into diversification rates within the genus in the Neotropics. Two lineages appear to have independently dispersed into South America around 3.5 Ma ago, one of which has radiated in the páramos (Brathys). We find strong support for the polyphyly of section Trigynobrathys, several species of which group within Brathys, while others are found in temperate lowland South America (Trigynobrathys s.str.). All páramo species of Hypericum group in one clade. Within these páramo Hypericum species enormous phenotypic evolution has taken place (life forms from arborescent to prostrate shrubs) evidently in a short time frame. We hypothesize multiple mechanisms to be responsible for the low differentiation in the ITS region contrary to the high morphological diversity found in Hypericum in the páramos. Amongst these may be ongoing hybridization and incomplete lineage sorting, as well as the putative adaptive radiation, which can explain the contrast between phenotypic diversity and the close phylogenetic relationships.

1 aNürk, Nicolai, M.1 aScheriau, Charlotte1 aMadriñán, Santiago uhttp://www.frontiersin.org/Journal/Abstract.aspx?s=1254&name=evolutionary_and_population_genetics&ART_DOI=10.3389/fgene.2013.0017502320nas a2200265 4500008004100000020001400041245010800055210006900163250001500232300001000247490000700257520148200264653002401746653001701770653003801787653001401825653001201839653001401851100002301865700002501888700002101913700002001934700002401954856007601978 2013 eng d a1055-790300aMolecular phylogenetics and morphological evolution of St. John's wort (Hypericum; Hypericaceae)0 aMolecular phylogenetics and morphological evolution of St Johns  a08.09.2012 a1--160 v663 a

Phylogenetic hypotheses for the large cosmopolitan genus Hypericum (St. John’s wort) have previously been based on morphology, and molecular studies have thus far included only a few species. In this study, we used 360 sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for 206 species representing Hypericum (incl. Triadenum and Thornea) and three other genera of Hypericaceae to generate an explicit phylogenetic hypothesis for the genus using parsimony and model-based methods. The results indicate that the small genus Triadenum is nested in a clade within Hypericum containing most of the New World species. Sister to Hypericum is Thornea from Central America. Within Hypericum, three large clades and two smaller grades were found; these are based on their general morphology, especially characters used previously in taxonomy of the genus. Relative to the most recent classification, around 60% of the sections of Hypericum were monophyletic. We used a Bayesian approach to reconstruct ancestral states of selected morphological characters, which resulted in recognition of characters that support major clades within the genus and a revised interpretation of morphological evolution in Hypericum. The shrubby habit represents the plesiomorphic state from which herbs evolved several times. Arborescent species have radiated convergently in high-elevation habitats in tropical Africa and South America.

10aCharacter evolution10aHypericaceae10aInternal transcribed spacer (ITS)10aPhylogeny10aThornea10aTriadenum1 aNürk, Nicolai, M.1 aMadriñán, Santiago1 aCarine, Mark, A.1 aChase, Mark, W.1 aBlattner, Frank, R. uhttp://www.sciencedirect.com/science/article/pii/S1055790312003314?v=s500445nas a2200121 4500008004100000245010400041210006900145300001100214490000600225100002300231700002100254856004800275 2011 eng d00aMorphological and phytochemical diversity among Hypericum species of the Mediterranean basin0 aMorphological and phytochemical diversity among iHypericumi spec a14--280 v51 aNürk, Nicolai, M.1 aCrockett, S., L. uhttps://hypericum.myspecies.info/node/2908901944nas a2200217 4500008004100000245008600041210006900127300001400196490000700210520126900217653000901486653001701495653002301512653001401535653001401549653001401563653002201577100002301599700002101622856008301643 2010 eng d00aCladistic analysis of morphological characters in Hypericum (Hypericaceae)0 aCladistic analysis of morphological characters in iHypericumi Hy a1495-15070 v593 a

Hypericum is a worldwide distributed genus with almost 500 species, including the medically used apomictic species H. perforatum. It is one of the few large plant genera where alpha taxonomy is nearly completed. To conduct a formal cladistic analysis of the genus, we coded 89 morphological characters for all described taxa, and analyzed the data with parsimony and Bayesian methods. The obtained trees indicate Hypericum to be monophyletic, if the monotypic genus Santomasia is included, and Lianthus as the sister group. The arrangement of the remaining genera of Hypericaceae included in the analysis is in congruence with molecular phylogenies. Apomorphic characters supporting the relationships of the genera are pointed out. The cladistic analysis revealed four groups within Hypericum: a basal grade containing Mediterranean species and three big clades containing most of the diversity of the genus. The borders of the Mediterranean Sea as part of the late Tethys Ocean are hypothesized as a probable area of origin for the genus. As indicated in the presented tree, a shrubby habit appears to be the ancestral state within Hypericum from which trees and herbs evolved, and apomixis originated at least three times independently within the genus.

10a_nmn10abiogeography10acladistic analysis10aevolution10aHypericum10aPhylogeny10aSt. John’s wort1 aNürk, Nicolai, M.1 aBlattner, F., R. uhttp://www.ingentaconnect.com/content/iapt/tax/2010/00000059/00000005/art00014