De-Extinctionists Look at Caspian Tiger and Tasmanian Tiger

If de-extinction – bringing an extinction species back into existence using cloning, selective breeding or some other means – becomes a reality, some experts argue that the first and potentially best candidates should be animals that are recently extinct. Two possibilities getting a lot of attention recently for very different reasons are the Caspian tiger and the Tasmanian tiger.

Caspian tigers (Panthera tigris virgata) weighed over 300 pounds and grew to ten feet in length when they inhabited Central Asia from the Caspian Sea in Turkey, through Iran and Iraq, to north-west China They were hunted, poisoned, developed and diseased to extinction during the era of the Soviet Union, with the last one reportedly killed in Turkey in 1970.

According to a new study in the journal Biological Conservation, biologists believe they can re-introduce the Caspian tiger using the Amur or Siberian tiger (Panthera tigris altaica), another tiger subspecies that still exists in a small area of northeastern Russia and is nearly identical genetically to the Caspian species. An area of Kazakhstan has been chosen that could support a population of 100 tigers and the wild animals they prey on within 50 years.

So technically this is a case of moving a nearly-identical species to an area, not a Jurassic Park-style de-extinction using DNA extracted from remains of an extinct species. That’s what’s being discussed in Australia with the Tasmanian tiger (Thylacinus cynocephalus). A new study in PLOS One reveals that researchers have been studying two of the four known preserved Tasmanian tiger brains and comparing them to the brains of Tasmanian devils (Sarcophilus harrisii).

Why? Since no one has proven to have seen one in the wild since 1930 (the last captive thylacine died in 1936), it would help to know what they acted like if they are ever de-extincted. The researchers used diffusion tensor imaging (DTI) to map the neural connections of the thylacine brains (an accomplishment considering they’re close to 100 years old) and compared them to the brains of the smaller, distantly-related devils. The tiger brains are more complex, indicating they were hunters rather than scavengers like the devils.

So? Assuming enough viable DNA material could be obtained to clone and de-extinct a Tasmainam tiger, how would we know if it looked and acted like the species when it was alive? The formation of the brain and its neural connections would go a long way towards proving it.

There’s no close cousin to the Tasmanian tiger that could be re-introduced to a small area of its former habitat. If there was, would it be a good idea? Is it a good idea to re-introduce tigers in an area that has changed dramatically since they were driven to extinction?

Are we doing this for science, entertainment or to relieve our guilt? The answer to that question may answer the rest.