Projects / Programmes source: ARIS

Inbreeding and evolutionary dead-ends: from population-level processes to macroevolutionary patterns

Research activity

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 
evolution, dead ends, inbreeding, diversity, sociality, spiders, Anelosimus
Evaluation (rules)
source: COBISS
Researchers (1)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  28289  PhD Ingi Agnarsson  Biology  Head  2007 - 2009  133 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0618  Research Centre of the Slovenian Academy of Sciences and Arts  Ljubljana  5105498000  63,134 
Due to habitat fragmentation and disappearing strains and breeds for human food production, the long term consequences of inbreeding on the evolutionary persistence of lineages is a rapidly growing concern for conservation and livestock genetics. Spider sociality has evolved repeatedly and each time results in a dramatic shift from outbred to strongly inbred populations structure, a shift that marks the beginning of the end for the lineage: the inbred social spiders are a remarkable example of replicate evolutionary dead-ends. This repeated evolutionary experiment offers a rare opportunity to study the phylogenetic and ecological consequences of changes in population genetic structuring within species. We propose to use data from multiple loci to (1) reconstruct the genetic history (via gene trees) within and between social and non-social species, (2) measure the change in genetic and phenotypic variability inferred by inbreeding, (3) examine the consequences of limited variation on evolvability and evolutionary fate of inbred lineages, and (4) the disconnect between the ecological and macroevolutionary time scales (or levels of selection) that may result in the repeated evolution of an evolutionary dead-end. This project brings the power of modern molecular techniques to a unique study system of evolutionary replicas, to bear on crucial questions in biology. While the social spiders are ideal tools to answer these questions, this project has broad implications for most of life.
Significance for science
This project uses a natural evolutionary experiment in spiders, an independent switch to inbreeding in multiple lineages, to understand the consequences of inbreeding in the long term. We focus on consequences of inbreeding in evolutionary time, that is, beyond initial inbreeding depression. Thus the project represents a novel and important approach to the problem of inbreeding. Our findings indicate marked effects of inbreeding and population structure on both the structuring and quantity of genetic variability. First, genetic variability is repackaged so as to represent nearly entirely between population variability with negligible within population variability (for one focal species Fst = 0.98). Second, even though variability is retained between populations, overall within inbred species variability is strongly reduced. Based on comparisons among multiple species, genetic variability in inbred social species is reduced by as much as 90%. As heterosis underlies the potential of species to respond to environmental change and/or disease, loss of genetic variability may explain why inbred social spiders represent an evolutionary dead-end. By extension, our results indicate that similar problems may face many wild populations in the long run, as human-induced habitat fragmentation increasingly forces species to switch from panmixia to inbred breeding system. Therefore, our results have important implications for conservation planning. We also have amassed a very large dataset that is yet to be analysed, which will further advance our understanding of the above questions and result in several additional publications supported by this project.
Significance for the country
As a novel line of research with world-wide relevance (e.g. conservation biology, agriculture) our project has the potential to place Slovenia on the map as a leader in the research of inbreeding consequences. As the only research program of its kind in Slovenia, it may open up novel areas of research for the next generation of Slovenian researchers.
Most important scientific results Final report, complete report on dLib.si
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