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Ancient DNA

 
 
 
Museum speciman of an iiwi (Hawaiian honeycreeper). A tiny fragment of skin provides DNA for analysis.
Photo credit: Jack Dumbacher
 
CCEG scientists participated in a study of the evolutionary relationships of the extinct quagga, a zebra that lost its stripes.
Photo credit: Michael Hofreiter

Ancient DNA (DNA isolated from things long dead such as subfossil bones, mummies, or museum specimens) methods are extremely useful in studies of conservation and evolutionary genetics. Careful application of these methods have enabled CCEG researchers to estimate the levels and patterns of genetic variation in a species even thousands of years ago, and how this variation has changed over time.

We can determine whether low genetic variation in a species was caused by recent human-caused declines in population size, or from declines that occurred more distant in the past (in, for example, the Hawaiian goose or nene and the Hawaiian petrel). Scientists can also use ancient DNA analysis to reconstruct evolutionary relationships of extinct and endangered animals, allowing us to better define species and populations and their evolutionary uniqueness.

Recently, using these methods, we found that the five honeyeater species that once lived in Hawaii (one until the 1980s) are not the same as Australasian honeyeaters, but were a unique family of Hawaiian birds related most closely to waxwings and silky flycatchers. Convergent evolution because of similar foraging habits caused the deceptive similarity.

Ancient DNA methods have also proven very useful for studies of wildlife disease. They can allow us, for example, to determine when invasive pathogens colonized native host populations, genetic changes in introduced vectors, and even to assess coevolution that can occur between host and parasite.

CCEG has been a leader in the application of ancient DNA methods to issues in conservation and evolutionary biology. Some of our other important studies involve extinct and endangered Hawaiian honeycreepers, black-footed ferrets, quaggas, Indian wolves, ivory-billed woodpeckers, and a new species of forest robin from Gabon.