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Combining ecology, micro- and macro-evolution into an integrated analysis of diversification

Titel Englisch Combining ecology, micro- and macro-evolution into an integrated analysis of diversification
Gesuchsteller/in Linder Hans Peter
Nummer 152982
Förderungsinstrument Projektförderung (Abt. I-III)
Forschungseinrichtung Institut für Systematische Botanik und Botanischer Garten Universität Zürich
Hochschule Universität Zürich - ZH
Hauptdisziplin Botanik
Beginn/Ende 01.12.2014 - 30.11.2018
Bewilligter Betrag 678'000.00
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Keywords (8)

biogeography; radiation; Cape flora; community ecology; diversity; ecology; speciation; evolution

Lay Summary (Deutsch)

Lead
Eine der ältesten Fragen der evolutionäre Biologie ist, weshalb manche Gebiete und manche Organismengruppen artenreicher sind als andere. Die Südafrikanische Kapflora ist weltweit eine der artenreichsten Floren. Sie hat eine Mischung artenarmer und artenreicher Gruppen. Anhand der Familie der Restionaceen werden wir die Muster und Entstehungsprozesse der Artbildung dieser Flora untersuchen. Artbildung kann auf zwei Ebenen untersucht werden: als Prozess welcher auf der genetischen Divergenz zwischen Populationen basiert (Populationsgenetik), und als Muster, welches auf den Unterschieden in den Artbildungsraten zwischen Artgruppen basiert (Makroevolution).
Lay summary

Wir testen die Hypothese, dass die Artbildungsrate einer Pflanzengruppe von der Zusammensetzung und Artenvielfalt der Pflanzengesellschaften und Habitate in denen diese Gruppe vorkommt, beeinflusst wird. Arten existieren nicht isoliert, sondern Überleben nur eingebettet in eine spezifische Pflanzengesellschaft. Wir dokumentieren die Restionaceengesellschaften, und ihre ökologischen Parameter, in der Kapflora. Weiter stellen wir die Listen der Arten (die Regionalflora) auf, aus denen diese Gesellschaften etabliert werden können. Wir postulieren, dass die Artenvielfalt und Zusammensetzungen der Gesellschaften, und auch die Vielfalt und Zusammensetzung der Regionalfloren, die Artbildungsrate beeinflussen. Die Muster vergangener Artbildung sollten sowohl in der phylogenetischen Struktur der Gesellschaften und der Regionalfloren, als auch in den Artaustauschmustern zwischen den Gesellschaften und Regionalfloren ersichtlich sein. Wir erwarten, dass Gesellschaftstruktur, die Prozesse der Artbildung, und die Muster der abgelaufenen Artbildungsprozesse miteinander verknüpft sind.

Direktlink auf Lay Summary Letzte Aktualisierung: 19.11.2014

Verantw. Gesuchsteller/in und weitere Gesuchstellende

Mitarbeitende

Verbundene Projekte

Nummer Titel Start Förderungsinstrument
126270 Niche evolution. A unifying concept for systematics, ecology, palaeontology and conservation biology 01.07.2009 Wissenschaftliche Tagungen
130847 Känozoische Angiospermen-Radiationen: Die Rolle von Klimaänderungen 01.12.2010 Projektförderung (Abt. I-III)

Abstract

The evolution of species diversity is a central theme in evolutionary biology, and there has been spectacular progress since the publication of the Origin of Species started the research field. In the latter half of the 19th Century Darwin explored the roles of natural and sexual selection in driving divergence, and in the early 20th Century the focus shifted to mechanisms that could interrupt gene flow during speciation. At the end of the 20th Century the ability to reconstruct phylogenetic history led to the exploration of the species radiations, and recent work linked niche concepts (time-equilibrium concepts) to evolutionary history (phylogenies, mapping niche variables over phylogenies) and started integrating these into macro-evolutionary concepts like adaptive radiations and biogeography. This led to the realization that global variation in biodiversity may be the consequence not only of environmental variables, but also of evolutionary history. Here we incorporate interspecific interactions into speciation and radiation, by explicitly using communities as the evolutionary arena, as the context for speciation, co-existence and radiation. Populations are the main units that evolve; they expand or decline into extinction in response to biotic and abiotic selection. The evolutionary fate of a species is an epiphenomenon of the evolutionary fates of all its constituent populations. That said, populations are linked by gene flow (plants) and migration (animals). Communities constitute the arena of interaction between populations of different species. This interaction can be mutualistic, facilitative, synergistic, competitive, or predatorial. Every species is part of at least one community, it is filtered into the community by its geographical presence, by its eco-physiological ability to deal with the abiotic conditions in the community, and by its ability to survive the biotic interactions within the community. It interacts with all members in a community through, inter alia, competition for resources (space, light, water, nutrients), facilitation (protection) or mutualism (dispersal, pollination). Membership of a community may be seen as evidence of successful integration. A species which cannot survive in at least one community will go extinct.We explore three phases in the evolution of diversity. The first is speciation, the origination of lineages that have unique evolutionary histories and fates. We explore the contributions of variables that limit gene flow between diverging lineages (allopatry, ploidy change, flowering time shift) and variables that select against intermediates (e.g. failure of intermediates to survive in at least one community) to the increase in genetic divergence among the diverging lineages, in the context of the emerging realization that genomic organisation might facilitate speciation with gene flow. The second is the continued coexistence of the recently diverged lineages, either due to geographical separation (found in the same community, but in different regions), or to niche shifts (either found in different communities in the same region, or occupying different alpha-niches within the same community). The third is the translation of speciation and continued coexistence in communities into macro-evolutionary patterns of diversity. These could be used to interpret historical periods of intense speciation in response to new ecological opportunities, or due to the evolution of key innovations. These leave a trace in community phylogenetics (phylogenetic clustering or overdispersion), and in the divergence patterns (diversification slowdowns). This approach accounts for the differences in alpha, beta and gamma diversity in terms of the speciation and co-existence, and for the patterns of radiation in terms of the number of niches available within a community, the number of communities in a region and the number of regions in the Cape flora.As study group we use the African Restionaceae, a typical element of the hyperdiverse Cape flora. Not only do we already have substantial background information on this family, but it is also suitably species rich. As such it is an excellent model group to explore the integration of pattern and process in diversification.
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