Center for Scientific Studies

Review of "Tasmanian Tiger : The Tragic Tale of How the World Lost Its Most Mysterious Predator"

by James A. Huggins, Ph.D., University Professor & Director of the Hammons Center for Scientific Studies

March 61, 2006 - Author David Owen has created an important historical narrative of the apparent demise of one of earth’s truly unique creatures.  I use “apparent demise” because Tasmania is a ruggedly beautiful and sparsely populated land that offers considerable space for a dog-sized creature to conceal itself.  Having lost something we humans have a tendency to go to great lengths to find it again.  Such is the case with this marsupial predator; perhaps even to the extent that our desire to reclaim what is past that our imagination runs away with us.  Ample testimony to this fact is provided by the observation that, according to Owen, one of every three human residents of the island has a “Tiger story” that purports the continued existence of Thylacinus cyanocephalus.  Indeed it seems that, despite the low probability that the science would assign this species any meaningful chance for survival, a whole nation longs for, and perhaps expects in many cases, its return. He further observes that the longer the animal remains deceased the more fascinated the Tasmanians, and in truth humans everywhere, become with it.  While imagination may run rampant, he vast number of sightings reported every year simply can not in totality represent contrived sightings to promote what has become almost a national symbol for Tasmania and, to some lesser degree, the world.  It is truly amazing how this vanished organism, the thylacine, has found its way into countless artist and literary expressions.  Since the 1980’s no less than 15 books of fiction have been written with the thylacine playing a prominent role.  This represents a complete reversal in the attitude that, for the greater part of a century, dominated the hearts of Tasmanian citizens.  For fifty years the “Tiger” battled against a superior and powerfully dominant species that desired no less than its complete extermination.  Perhaps the tremendous national desire to see this animal resurrected is a subconscious desire to right the wrong that was done this singular creature in God’s kingdom.  No doubt many fantasize about its stealthy movement across rugged Tasmanian terrain but it is equally obvious that scores of people believe it still exists.

These animals, which were painted like zebras, looked like dogs (canids) but were obviously marsupials, so confused early taxonomists that the Latin name was changed three times before finally settling in 1824 as Thylacinus cyanocephalus.  As a marsupial this creature carried its 3 to 4 young in a backward facing pouch along the abdomen.  Young tigers were born deaf, blind, and without hind limbs.  However, like modern extant marsupials, the young, guided by instinct from behavioral genes, found their way into the pouch where they fastened themselves to the mother’s teats.  As adults they were the size of a Laborador retriever but with a distinctively different look.  Their jaws gaped to immense size, they possessed more incisors than dogs, and they lacked the ability to grind bones as do their canid look-a-likes since their molars were not nearly so powerfully built.  They were tan in color and had as many as 20 dark stripes coming off the back and down their sides.  Sexual dimorphism was evident with males being larger. Relatively recent discoveries of fossil marsupials in the Gobi Desert have confused the current evolutionary thought surrounding these animals.  Originally discovered by Ray Chapman, the model for the popular motion picture hero Indiana Jones, these specimens illustrate that the marsupial tiger, as is the case for some other marsupials, was never restricted to the regions of Australia.  It is commonly thought that when ranges of similar placental and marsupial mammals overlapped placental mammals were able to win the war of resource competition; thereby driving many marsupial species into extinction.

Large predators live on the edge of survival as individuals and as a species simply because of the Eltonian pyramid of numbers.  This pyramid tells us that when considering the dissipation of energy throughout natural systems there is a great deal less energy available at the top of the pyramid i.e. those sites occupied by predators.  To be sure, the human introduction of the dingo and other canids put two similar predators into competition.  In addition, the territory from which the large predator must extract energy will of necessity be large.  Habitat reduction can therefore be extremely detrimental for such predators as available resources will diminish concomitantly.   The problems presented by competition, habitat reduction and decreases in available resources are confounded when habitat shrinks to the point that there is no longer enough suitable and available space to support the maintenance of a healthy gene pool (keeping inbreeding to a minimum).  The level of heterozygosity is an extremely important component of viable vertebrate populations.

The last known marsupial tiger died September 7, 1936 at the Hobart Zoo after a century of species persecution.  Fifty years later to the day it was declared extinct.  This represents the standard period of time that the world’s experts will list a species, after repeated attempts to document its existence have met with failure, as extinct.  Professor Thomas Flynn (father of actor Erol Flynn) called for the creation of a sanctuary for these creatures as early as 1914.  I wish his famous son had seen fit to purchase and set aside such ecological protection for the thylacine.  Alas he did not.  Unfortunately similar episodes have graced the historical pages of man’s interaction with other predators.  This scenario has been played out, though the entire course may not have been so completely run, with the wolf, the bear, the tiger, the shark, and the list goes on.  As has been the case for so many of the animals which man has viewed as a competitor in the economy of life, there was a bounty on the thylacine for his infrequent attempts at eating sheep.  Despite considerable evidence that minimized the damage inflicted upon agrarian industry, the species was not granted a reprieve until 1936, a mere two months before the last specimen died.

To this point the story is a familiar one; however, the Australian Museum has added a new twist to this extinction story by undertaking the extremely bold and controversial task of cloning a Tasmanian tiger by the year 2010.  Cells collected from the 200 odd specimens housed in museums across the globe yielded cells from three specimens that are thought to be usable.  The DNA from a pup preserved in 1866 within ethyl alcohol is purported to show considerable promise.  In fact, it has been announced that using polymerase chain reaction techniques that some thylacine genes have been successfully replicated.  However, this achievement is light years from an entire genetic library of this animal.  I wish them luck but I have my doubts about a 2010 triumph. 

The Tassi Tiger has understandably become a potent symbol of wildlife conservation.  Its story symbolizes wanton, careless destruction of the natural world in the name of the security and defense of human property.  It belies the observation that humans, as the keystone species which controls the veritable future of this planet, appears bent upon shirking our responsibility for preserving our natural heritage.  As a species we can’t seem to place any “other” above our perceived immediate needs.  Unfortunately the use and preservation of natural resources are inextricably linked to the economies of nations and the human entities thereof.  Such has all too frequently tolled the irrevocable death knell and led to the final and complete loss of many irretrievable biological treasures.