The common ancestor of camels and llamas, Procamelus, evolved in North America around 11 million to 14 million years ago, and its descendants migrated to Asia and Africa where they eventually developed into modern camels.  The ancestor of the guanaco entered South America by way of the newly formed isthmus of Panama some 5 million years ago.  Geneticists estimate the minimum divergence time between the Asian and American camelids at about 11 million years.     "A camel is six times the size of the wild guanaco mother, but the baby was the size of a normal guanaco calf," says Short.

. Tiger quolls (Dasyurus maculatus).  Could females of this species prove to be suitable surrogate mothers for artificially produced thylacine embyos?

    "The mother's system somehow overrides any tendency to produce a huge baby.  But since the hybrid was born, it has grown like a rocket - it's already much bigger than the mother."

    Embryo size probably wouldn't be a problem if a quoll or Tasmanian devil served as a surrogate mother to a thylacine embryo.  All large marsupials, including thylacines, are born no larger than about 2.5 cm (1 in.) in size - although pouch space could prove to be an issue later.

    However, there would remain other intimidating difficulties to creating a viable thylacine embryo.  Short says that even though they have made hundreds of attempts, scientists have yet to achieve successful interspecific clones between distantly related animals such as sheep, cattle and pigs.

    Even when nuclei are taken from fresh cells of living animals, they fail to develop in the host oocytes - the nuclei of sheep, for instance, refuse to develop in cow or pig oocytes, and vice-versa.  Short believes that it would be far more difficult to clone nuclei obtained from dehydrated thylacine cells into quoll or Tasmanian devil oocytes.
 

. One of five preserved thylacine pouch young in the collection of the Tasmanian Museum and Art Gallery, Hobart.  This male was about three months old when collected, and thus has only a sparse amount of hair.

Professor Alan Trounson, pioneering IVF (In Vitro Fertilization) researcher of Monash University, believes that cloning of the thylacine will be "basically impossible" using science's current level of technological development.  "When you pickle something in alcohol, it displaces all the water in the tissue, and you can't rehydrate it," said Trounson.  "But then, I didn't think they would be able to clone Dolly the sheep, so what do I know?"     Ethyl alcohol preserves tissue and genes, but in doing so, water, the very substance which is vital to life, is expelled.  Researchers would need to rehydrate not only the DNA in the thylacine nuclei, but the entire matrix of nuclear proteins and enzymes that maintains its structure, and conducts its orderly replication as the cell divides and multiplies.  Therefore, more is needed than just the coded instructions for how to build a thylacine.  Obtaining the complete package of necessary biochemical components will be the determining factor in whether thylacine cloning is a success or failure.     Trounson is less discouraged about the prospect of Japanese researchers which may eventually succeed in resurrecting a Woolly mammoth Mammuthus primigenius - or at least, a hybrid between the mammoth and its close relative, the Indian elephant, Elephas gigas.     Hopefully, some male mammoth which was quickly frozen in Siberian permafrost around 10,000 years ago could provide viable, dehydrated sperm that could be revived - as is the case with sperm stored in liquid nitrogen - to fertilize an egg from an Indian elephant.  It is speculated that the elephant would prove to be an ideal surrogate mother.  Presumably a descendant of early mammoths, it is genetically more similar to the woolly mammoth than a guanaco is to a camel.

    Trounson believes that advancements in technology might allow scientists several hundred years from now to reconstruct a thylacine from scratch.  With existing technologies, it should be rather routine to clone the entire genetic program of the thylacine and keep it in storage until the technology is ready.  The thyacine's blueprint would be preserved as an array of overlapping DNA sequences spliced into the chromosomes of E. coli bacteria, and indefinitely maintained as a self-perpetuating "DNA library".