Restoring faith in conservation action: maintaining wild genetic diversity through the Tasmanian devil insurance program

Conservation breeding programs aim to maintain 90% wild genetic diversity,
but rarely assess functional diversity. Here, we compare both genome-wide
and functional diversity (in over 500 genes) of Tasmanian devils
(Sarcophilus harrisii) within the insurance metapopulation and across the
species’ range (64,519 km2). Populations have declined by 80% since 1996
due to a contagious cancer, devil facial tumour disease (DFTD). However,
predicted local extinctions have not occurred. Recent suggestions of
selection for “resistance” alleles in the wild precipitated concerns that
insurance population devils may be unsuitable for translocations. Using
830 wild samples collected at 31 locations between 2012-2021, and 553
insurance metapopulation devils, we show that the insurance metapopulation
is representative of current wild genetic diversity. Allele frequencies at
DFTD-associated loci were not substantially different between captive and
wild devils. Methods presented here are valuable for others investigating
evolutionary potential in threatened species, particularly ones under
significant selective pressures.