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| Titel |
Constant diversification rates of endemic gastropods in ancient Lake Ohrid: ecosystem resilience likely buffers environmental fluctuations |
| VerfasserIn |
K. Föller, B. Stelbrink, T. Hauffe, C. Albrecht, T. Wilke |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 23 ; Nr. 12, no. 23 (2015-12-10), S.7209-7222 |
| Datensatznummer |
250118207
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| Publikation (Nr.) |
 copernicus.org/bg-12-7209-2015.pdf |
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| Zusammenfassung |
Ancient lakes represent key ecosystems for endemic freshwater species. This
high endemic biodiversity has been shown to be mainly the result of
intra-lacustrine diversification. Whereas the principle role of this mode of
diversification is generally acknowledged, actual diversification rates in
ancient lakes remain little understood. At least four types are conceivable.
Diversification rates may be constant over time, they may fluctuate, rates
may be higher in the initial phase of diversification, or there may be a
pronounced lag phase between colonization and subsequent diversification. As
understanding the tempo of diversification in ancient lake environments may
help reveal the underlying processes that drive speciation and
extinction, we here use the Balkan Lake Ohrid as a model system and the
largest species flock in the lake, the non-pyrgulinid Hydrobiidae, as a
model taxon to study changes in diversification rates over time together
with the respective drivers.
Based on phylogenetic, molecular-clock, lineage-through-time plot, and
diversification-rate analyses we found that this potentially monophyletic
group is comparatively old and that it most likely evolved with a constant
diversification rate. Preliminary data of the SCOPSCO (Scientific Collaboration On Past Speciation Conditions in Lake Ohrid) deep-drilling program
do indicate signatures of severe environmental/climatic perturbations in
Lake Ohrid. However, so far there is no evidence for the occurrence of
catastrophic environmental events. We therefore propose that the constant
diversification rate observed in endemic gastropods has been caused by two
factors: (i) a potential lack of catastrophic environmental events in Lake
Ohrid and/or (ii) a probably high ecosystem resilience, buffering
environmental changes. Parameters potentially contributing to the lake's
high ecosystem resilience are its distinct bathymetry, ongoing tectonic
activities, and karst hydrology.
The current study not only contributes to one of the overall goals of the
SCOPSCO deep-drilling program – inferring the driving forces for biotic
evolution in Lake Ohrid. It might also enhance our understanding of how
ecosystem resilience, in general, may promote relatively constant
diversification rates in isolated ecosystems. However, we encourage future
studies testing hypotheses about the lack of catastrophic events in Lake
Ohrid. These studies should be based on high-resolution data for the entire
geological history of the lake, and they should potentially involve information from
the sediment fossil record, not only for gastropods but also for other
groups with a high share of endemic taxa. |
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