Abstracts (first author)

Talk 

Museum DNA reveals a drastic and recent bottleneck in the Seychelles warbler

Author(s): Spurgin LG, Wright DJ, Collar NC, Komdeur J, Burke TA, Richardson DS

Summary:

Understanding the population history of endangered species is important for interpreting contemporary ecological processes, and of conservation high importance. We use microsatellite markers and museum specimens to examine 140 years of genetic diversity change in the Seychelles warbler (Acrocephalus sechellensis), a model system for evolutionary and conservation biology. In the 1960s this species was reduced to ca 30 individuals on a single island, but it is unknown whether it has ever been widespread and abundant. Across museum and contemporary samples, we found a 25% reduction in genetic diversity, which resulted in significant genetic structure. Using simulations we show that the warbler was bottlenecked from a large, outbred population. An ancestral effective population size of over 2,000 was reduced to less than 50 within the last century, which most likely occurred due to human disturbance. The approaches used form a powerful way of inferring population history, thus helping us to understand ecological processes and inform conservation.


Video


Abstracts (coauthor)

What drives the rapid regeneration of MHC diversity amongst recently bottlenecked populations?

Author(s): Richardson, DS, Van Oosterhout C, Emerson BC, Illera J, Bridgett S, Gharbi K, Spurgin LG

Summary:

.Population bottlenecks can restrict variation at functional genes, reducing the ability of populations to adapt to new and changing environments. Understanding how populations generate adaptive genetic variation following bottlenecks is therefore central to evolutionary biology. The major histocompatibility complex (MHC) is a multigene family that provides an ideal model for studying adaptive genetic variation due to its central role in pathogen recognition. While de novo MHC sequence variation is generated by point mutation, gene conversion can generate new haplotypes by transferring sections of DNA within and across duplicated MHC loci. However, the extent to which gene conversion generates new MHC haplotypes in wild populations is poorly understood. We used a 454 sequencing protocol to screen MHC variation across all 13 island populations of Berthelot’s pipit (Anthus berthelotii). The recent colonisation of this species (<75,000 years ago), along with the replicated island system gave us a unique opportunity to identify which MHC alleles were involved in the original colonisation events, and which have been generated in situ, post colonisation. This, in turn, allowed us to identify how new MHC haplotypes have been regenerated across the island populations. In light of these results, I will discuss the roles of mutation, gene conversion and selection in generating and maintaining functional genetic diversity in bottlenecked populations.

Contacts

Chairman: Octávio S. Paulo
Tel: 00 351 217500614 direct
Tel: 00 351 217500000 ext22359
Fax: 00 351 217500028
email: mail@eseb2013.com

Address

XIV Congress of the European Society for Evolutionary Biology

Organization Team
Department of Animal Biology (DBA)
Faculty of Sciences of the University of Lisbon
P-1749-016 Lisbon
Portugal

Website

Computational Biology & Population Genomics Group 
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