Gremiensitzungen


Freitag, 11. Juli 2014 - 13:15 Uhr
GEO-Gebäude, Raum 1550 (Hörsaal)
Agnes Weiner

Planktonic foraminifera have a long tradition as proxies for the reconstruction of past ocean and climate conditions. In order to achieve a high resolution of these reconstructions an exact species classification as well as knowledge of the ecological adaptations of a species is highly important. So far, species classification was conducted using morphological characteristics of the calcite shell. With the application of molecular genetic approaches on living planktonic foraminifera, the classical species concept, however, has been challenged by the discovery of a large number of cryptic species “hidden” within the morphospecies.
The studies for my dissertation focused on establishing a connection between information from the fossil record and the genetic background in extant species in order to find out to what degree morphologically defined species reflect real biological diversity. I used molecular genetic techniques in combination with morphometric analyses to examine the extent of cryptic genetic diversity in selected morphospecies and its relation to morphological traits. This connection helped to resolve the taxonomy and validity of certain questionable morphospecies. Furthermore, I analyzed the biogeographic distribution patterns of extant species in order to differentiate between species with local adaptations and endemism versus species with global dispersal and gene flow.



Publications:
Weiner A, Weinkauf M, Kurasawa A, Darling K, Kucera M, Grimm G (2014) Phylogeography of the tropical planktonic foraminifera lineage Globigerinella reveals isolation inconsistent with passive dispersal by ocean currents. PLoSONE, 9(3): e92148.
André A, Weiner A, Quillévéré F, Aurahs R, Morard R, Douady CJ, de Garidel-Thoron T, Escarguel G, de Vargas C, Kucera M (2013) The cryptic and the apparent reversed: lack of genetic differentiation within the morphologically diverse plexus of the planktonic foraminifer Globigerinoides sacculifer. Paleobiology, 39(1): 21-39.
Weiner A, Aurahs R, Kurasawa A, Kitazato H, Kucera M (2012) Vertical niche partitioning between cryptic sibling species of a cosmopolitan marine planktonic protist. Molecular Ecology, 21(16): 4063-4073.




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