Abstract:
|
The Montseny brook newt (Calotriton arnoldi), considered the most endangered amphibian in Europe, is a
relict salamandrid species endemic to a small massif located in northeastern Spain. Although conservation
efforts should always be guided by genomic studies, those are yet scarce among urodeles, hampered by
the extreme sizes of their genomes. Here, we present the third available genome assembly for the order
Caudata, and the first genomic study of the species and its sister taxon, the Pyrenean brook newt (Calotriton
asper), combining whole-genome and ddRADseq data. Our results reveal significant demographic
oscillations which accurately mirrored Europe’s climatic history. Although severe bottlenecks have led to
depauperate genomic diversity and long runs of homozygosity along a gigantic genome, inbreeding
might have been avoided by assortative mating strategies. Other life history traits, however, seem to
have been less advantageous, and the lack of land dispersal has driven to exceptional levels of population
fragmentation. |