Projects / Programmes
The unity of biogeographic history in a cave fauna and its causes
| Code |
Science |
Field |
Subfield |
| 1.03.01 |
Natural sciences and mathematics |
Biology |
Zoology and zoophysiology |
| Code |
Science |
Field |
| B320 |
Biomedical sciences |
Systematic zoology, taxonomy, zoogeopraphy |
| Code |
Science |
Field |
| 1.06 |
Natural Sciences |
Biological sciences |
Stygobionts, Dinaric Karst, phylogeography, biogeographic patterns, vicariance, speleobiology
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
25832 |
PhD Valerija Zakšek |
Biology |
Head |
2011 - 2013 |
136 |
Organisations (1)
Abstract
Common patterns in the biogeographic history of cave fauna and their causes
Historical biogeography, conservation biology, and evolutionary ecology require information about how historical patterns and processes have shaped lineage diversification at various spatial and temporal scales. It is important to understand how specific historical processes, and specific biogeographic boundaries, may have similarly or differentially impacted on lineages.
Scientific background. Phylogeographic analyses of three aquatic subterranean taxa with similar distribution patterns along the entire Dinaric Karst: the European cave salamander Proteus anguinus, the cave shrimps Troglocaris s. str. and the cave tube worm Marifugia cavatica), revealed that all taxa are highly genetically structured and have similar distribution of phylogroups. The most parsimonious explanation for the common patterns of evolutionary history shared by several different taxa, is by past vicariant events affecting ancient populations.
Problem identification. The Dinaric Karst area is well known for its high hydrographical fragmentation and a dynamic geologic history due to tectonic shifts, as well as past hydrographic changes and climatic changes. A concordant phylogeographic structure of diverse subterranean taxa in the Dinaric Karst suggests the same underlying vicariant events, therefore the question arises: which event(s)? The existent age estimates for the concordant phylogroups of the European cave salamander, the cave shrimps and the cave tube worm are contradictory. The estimates are based either on the substitution rate estimates of other taxa (for the European cave salamander and the cave shrimps) or on the fossil records (for the cave tube worm). While there is no other reliable biogeographical calibration points available for the Dinaric Karst the relevance of the estimates remains questionable. A thorough comparison of both, the relative and the corrected absolute timing would thus enable our testing of the hypothesis: that the same historical events are responsible for similarities in the phylogeographic structure in all studied taxa. As the distribution of the amphipod Niphargus steueri coincides with the distributions of the above mentioned taxa, we might test the hypothesis: about the common phylogeographic patterns of the aquatic cave fauna, by clarifying the amphipod’s phylogeography.
Objectives of the proposed research.
To identify the importance of vicariant events in the evolution of the subterranean taxa on the basis of concordant phylogeographic structure of different model organisms, and to test the impact of several environmental factors: hydrography, geology and climate.
To determine the importance of historical and recent hydrographic connections for the current population structure in the case of cave shrimps (the only taxon with large enough samples available).
To estimate the age of common phylogeographic events and to highlight the biogeographical history of the Dinaric Karst.
To complement the list of the conservation priorities of the Dinaric Karst, with new endemic taxa and new data on their distribution and status, especially in Slovenia.
Significance for science
A new scientific knowledge about phylogeographical patterns and processes of several aquatic subterranean taxa distributed along the Dinaric karst represent a step forward in understanding of evolution, biogeography and biodiversity in subterranean environment. We find the following findings as the most important for further scientific development: - During the research of phylogeny and phylogeography of the clade of cave amphipods we found out non adaptive radiation in allopatry, meanwhile radiation in sympatry is adaptive leading to evolution of new ecomorphs. We showed that the main process leading differentiation from an ancestral lake ecomorph to so called daddy longleg ecomorph is competition and occupancy of ecological niches. - In the case study of cave shrimps we showed that genetic differentiation and connectivity of subterranean populations is not concordant to recent and known underground water connections, but is most probably a result of past hydrographical connections. - We have showed a paradox of syntopy of two cryptic lineages of aquatic subterranean taxa, in which it is known that ranges of cryptic taxa are mainly allopatric. And thus confirmed that larger number of specimens and a dense sampling of populations is needed to have good overview and to understand its phylogeograhic structure. - We have summarized that different taxa on the Dinaric karst inhabits the same areas, although the concordant areas between taxa are a result of diverse biogeographic history and processes of each taxon. - When using phylogeography and genetic diversity centers of distribution of phyletic lineages were identified on the Dinaric karst, which could represent significant conservation units (CSU) and units for research of hydrographical and geological history of the Dinaric karst.
Significance for the country
First scientific description and discoveries of subterranean fauna started in Slovenia, Slovenia is a global hotspot of subterranean biodiversity, which we study and with results of scientific studies we contribute to the maintenance of international importance of Slovenian speleobiology. During the project we studied a genetic differentiation and diversity of selected aquatic subterranean taxa, which might be recognized as a key and an umbrella species for conservation of subterranean biodiversity. The results have significantly improved our knowledge about distribution of some taxa and the knowledge about their genetic differentiation represents a good scientific background for strategies of conserving subterranean biodiversity. An indirect role of this project is educational one, which is reflected through the education of young researchers in field of speleobiology and phylogeography (co-mentor of two student theses) and in international cooperation. During the research project a cooperation with several PhD students and researchers was established and they have been on practical training in our molecular laboratory, where they completed a main part of their research. By education of foreign students we also contribute to visibility and add to Slovenian science credit.
Most important scientific results
Annual report
2011,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2011,
final report,
complete report on dLib.si
