DNA Analysis of California Condor Specimens Reveals Substantial Genetic Diversity Prior to Recent Bottleneck

The existing genetic diversity of California Condors, all of which are descended from just 14 individuals, is strikingly low. But were condors more genetically diverse before their 20th century population crash, or were they already, as one paleontologist put it in the 1940s, a Pleistocene relict with "one wing in the grave?" The researchers behind a new study in the November 2016 issue of The Condor: Ornithological Applications analyzed samples from condor museum specimens dating back to the 1820s and found that the historical population was surprisingly diverse, but that a substantial amount of that diversity was lost in the last two centuries. This finding supports the hypothesis that condors were fairly widespread and abundant prior to increases in human-caused mortality, which likely drove their numbers down quickly in the 1800s and early 1900s. Analyzing the museum specimens' mitochondrial DNA, Jesse D'Elia, Ph.D., of the U.S. Fish and Wildlife Service and his colleagues showed that more than 80% of the unique haplotypes present in the birds of the past have disappeared from the gene pool of condors alive today. The low amount of genetic diversity in the current population, which is descended from only 14 genetic founders from the captive flock, was already well known, but this is the first study to show that there was substantial genetic diversity in the historical population. Dr. D'Elia and his colleagues used tissue samples from 93 California Condor specimens collected between 1825 and 1984 in locations ranging from Mexico to Washington state. "The value of museum collections for answering important questions when considering population translocations and species' reintroductions cannot be overstated," says Dr. D'Elia.
Login Or Register To Read Full Story