The Devil is in the Details: Genetic Diversity and the Endangered Tasmanian Devil

If you are of a certain age, the name “Tasmanian Devil” most likely conjures up an image of a ferocious brown hairy cartoon character that traveled in the center of a tornado of chaos. Sometimes, as in this case, the truth is much less strange than the fiction. The real Tasmanian Devils (Sarcphilus harrisii) are relatively small, somewhat cuddly looking, marsupials found only on the island of… you guessed it, Tasmania. Despite their diminutive size, they are the largest living carnivorous marsupial.  Unfortunately, these terrier-sized animals are also in danger of becoming extinct, largely as a result of a deadly, infectious transmissible cancer called Devil Facial Tumor Disease (DFTD). Continue reading

Don’t Judge a Cheetah by Its Spots: New Insights into the Genetics and Evolutionary History of African and Asiatic Cheetahs

The genetics of wild cheetah (Acinonyx jubatus) populations has a special significance for me. In fact, it could be said that the population genetics of cheetahs changed my life.  I first learned about the low genetic variability in cheetahs in a darkened lecture hall at Iowa State University in 1988. I was so fascinated by what I learned in those lectures about genetics and its importance in conservation efforts that I eventually changed my major to Genetics.  “The Cheetah Papers” as a colleague calls them, were, and perhaps still are, common teaching tools for biology and genetics classes. And why not? The results were amazingly cool, if a bit disturbing. Imagine a population that, through a series of natural events over thousands of years, had become so genetically similar to one another as to be almost clonal.

Still, if science teaches us nothing else, it teaches us that there is always more to the story. Continue reading

The Latest On: When Five Hundred Tigers Are Not Enough

Bengal tiger growling

It is sad but true that the latest news has not been promising for wild tiger populations. In September, an article published in PLoS Biology (1) estimated that the best hope of saving the wild tiger population would be to shift focus to source sites, which are “…at spatially well-defined priority sites, supported by proven best practices of law enforcement, wildlife management, and scientific monitoring.” The authors estimate the cost to save these sites at $82 million (U.S). At the time of publication, $47 million had been committed by governments and other groups. It isn’t difficult  math to figure out there is a deficit.   Continue reading

Caspian Tigers: Extinction Not Quite Forever?


The Caspian Tiger might not be as extinct as once believed.

When is an extinct subspecies not extinct? Maybe when it is not really a subspecies at all— The tiger subspecies Panthera tigris virgata, or Caspeian Tiger, was purported to have become extinct in February of 1970 when the last survivor was shot in Turkey. Leaving aside the hard to grasp idea that we might know down to the month when a species became extinct because someone shot the last one, it is clear that one tiger can hardly make little tigers by itself, so that subspecies was already doomed. Or was it? Continue reading

When Five Hundred Tigers Are Not Enough



In my sophomore year at Iowa State University, I sat enthralled in a dark lecture hall as my animal genetics professor described studies done on wild populations of cheetahs that had found that the animals were so genetically similar that they could almost be called clones. Past bottlenecks in the cheetah population meant that and even though population numbers had rebounded, the individuals were so genetically similar that the effective breeding population was much smaller. I was hooked. A week later I changed my major from “Pre-vet” to Genetics. Continue reading