Compared to their mainland congener , Channel Islands foxes are dwarves with little genetic variation . In fact , one of these island populations may be the least genetically varying population of all wild animals , according to findings published inCurrent Biologylast week .
Channel Island foxes ( Urocyon littoralis ) evolved from gray Charles James Fox convey over to the islands by man some 7,000 years ago . today , they experience on six of California ’s Channel Islands . They ’re about two - tierce the sizing of foxes experience on mainland southern California , and like many island coinage , they ’re not really afraid of humans . These isolated island population have persevere for thousands of years at exceedingly small universe sizes . But in the last brace of decade , four of these subspecies – from San Miguel , Santa Rosa , Santa Cruz , and Santa Catalina – were listed as endangered after predation from non - aboriginal golden eagles and the introduced canine tooth distemper virus make catastrophic declines .
A team led by UCLA’sRobert Waynesequenced the genome of Channel Island slyboots representing all six population as well as one mainland gray fox ( Urocyon cinereoargenteus ) from southerly California using desoxyribonucleic acid sample collected in 1988 before their recent declines , with the programme to forge a manikin for prospicient - term conservation of diminished endangered populations .
Not only do island foxes have drastically decreased familial mutation , they also have high levels of deleterious mutant compared to the gray fox . That suggests survival has n’t regorge their genome of harmful variants . Specifically , island foxes show a 3- to 84 - fold reduction in what ’s called heterozygosity . That ’s when an individual inherits different variants of a gene from its parents .
In especial , the San Nicolas Island fox showed the most extreme reducing of heterozygosity : They have a cheeseparing absence of version . After sequencing the genomes of two San Nicolas soul , the team found that they were nearly monovular . This unique instance of " genomic flatlining " in all likelihood should n’t bode well , yet this small universe has negociate to survive .
" The academic degree to which the San Nicolas foxes have lost transmissible sport is singular , upholding a previous observance that they may be the least genetically variable population of wild animals bed , " Wayne said in astatement . " It indicate that under some conditions , genetic variation is not dead all important for the persistence of endangered populations . "
