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Université de Fribourg

Molecular ecology studies of species radiations: current research gaps, opportunities and challenges

la Harpe, Marylaure de ; Paris, Margot ; Karger, Dirk N. ; Rolland, Jonathan ; Kessler, Michael ; Salamin, Nicolas ; Lexer, Christian

In: Molecular Ecology, 2017, p. -

Understanding the drivers and limits of species radiations is a crucial goal of evolutionary genetics and molecular ecology, yet research on this topic has been hampered by the notorious difficulty of connecting micro- and macroevolutionary approaches to studying the drivers of diversification. To chart the current research gaps, opportunities and challenges of molecular ecology approaches to...

Université de Fribourg

Sino-Himalayan mountains act as cradles of diversity and immigration centres in the diversification of parrotbills (Paradoxornithidae)

Liu, Yang ; Hu, Junhua ; Li, Shou-Hsien ; Duchen, Pablo ; Wegmann, Daniel ; Schweizer, Manuel

In: Journal of Biogeography, 2016, vol. 43, no. 8, p. 1488–1501

Aim: Montane regions like the Sino-Himalayas constitute global diversity hotspots. Various mechanisms such as in situ adaptive divergence, speciation following immigration or allopatric diversification in complex landscapes have been proposed to account for the exceptional diversity found in a particular clade in a montane setting. We investigated macroevolutionary patterns to test these...

Université de Fribourg

Is hybridization driving the evolution of climatic niche in Alyssum montanum

Arrigo, Nils ; La Harpe, Marylaure de ; Litsios, Glenn ; Zozomová-Lihová, Judita ; Španiel, Stanislav ; Marhold, Karol ; Barker, Michael S. ; Alvarez, Nadir

In: American Journal of Botany, 2016, p. -

PREMISE OF THE STUDY: After decades of interest, the contribution of hybridization to ecological diversification remains unclear. Hybridization is a potent source of novelty, but nascent hybrid lineages must overcome reproductive and ecological competition from their parental species. Here, we assess whether hybrid speciation is advantageous over alternative modes of speciation, by comparing...

Université de Fribourg

Dynamic optimal capital growth of diversified investment

Yonga, Luo ; Bo, Zhu ; Yong, Tang

In: Journal of Applied Statistics, 2015, vol. 42, no. 3, p. 577–588

We investigate the problem of dynamic optimal capital growth of diversified investment. A general framework that the trader maximize the expected log utility of long-term growth rate of initial wealth was developed. We show that the trader's fortune will exceed any fixed bound when the fraction is chosen less than critical value. But, if the fraction is larger than that value, ruin is almost...

Université de Fribourg

‘Next generation’ biogeography: towards understanding the drivers of species diversification and persistence

Lexer, Christian ; Mangili, Sofia ; Bossolini, Eligio ; Forest, Felix ; Stölting, Kai N. ; Pearman, Peter B. ; Zimmermann, Niklaus E. ; Salamin, Nicolas

In: Journal of Biogeography, 2013, p. -

The drivers of species diversification and persistence are of great interest to current biogeography, especially in those global biodiversity ‘hotspots’ harbouring most of Earth's animal and plant life. Classical multispecies biogeographical work has yielded fascinating insights into broad-scale patterns of diversification, and DNA-based intraspecific phylogeographical studies have started to...

Université de Fribourg

Diversification and limited information in the Kelly game

Medo, Matúš ; Pis’mak, Yury M. ; Zhang, Yi-Cheng

In: Physica A: Statistical Mechanics and its Applications, 2008, vol. 387, no. 24, p. 6151-6158

Financial markets, with their vast range of different investment opportunities, can be seen as a system of many different simultaneous games with diverse and often unknown levels of risk and reward. We introduce generalizations to the classic Kelly investment game [J.L. Kelly, IEEE Transactions on Information Theory 2 (1956) 185–189] that incorporates these features, and use them to investigate...