Carnivorous Nights by Margaret Mittelbach Read Free Book Online

ultimate stage of the project: cloning a tiger.
    “Of course, having just one wouldn't do any good,” Karen said. “We'd have to make at least two hundred tigers.” Then she and Don began to laugh. Even in the heart of the cloning project it seemed like science fiction.
    “There's really a lot of pressure,” said Don, still laughing and wiping tears from his eyes. The chances of success—of creating just one thylacine— were 5 to 8 percent in twenty years.
    But, he added, the odds could get better. Technology was improving all the time. Since the discovery of the structure of DNA in 1953, scientists have learned to dissect, copy, map, manipulate, and even change the code of life. Through genetic modification, they've created insectresistant breeds of corn. Tomatoes that have extended shelf lives. They have bioengineered cows to produce “farmaceuticals,” including potential treatments for blood clots, anemia, hemophilia, and emphysema. They have put bioluminescent jellyfish DNA into white rabbits to make them glow under ultraviolet light—and they have even introduced spider DNA into goats, causing them to produce copious amounts of superstrong silk webbing in their milk.
    Cloning, or bringing to life the twin of an individual, has also become a reality. The first mammal clone, Dolly the Sheep, was created in 1996 from a single cell nucleus taken from the udder of an adult sheep. Recently,clones of the first endangered species were created by implanting their DNA into the eggs of related animals.
    The first such trans-species birth was in 2001 when a cloned guar— an extremely rare species of wild ox that lives in Southeast Asia— was brought to term inside a cow named Bessie. This experiment was followed up in 2003 when a cloned Javanese banteng, a rare species of wild cattle, was born on an Iowa farm. The banteng's “mother” was a beef cow. In China, scientists are currently working to produce embryonic clones of giant pandas that could be “mothered” by black bears.
    This is how the tiger clone would be created. If cloning scientists are able to reconstitute the thylacine's genome, they will need to pick a species to be the tiger's surrogate mother, an Eve for a new race of thylacines. This animal will have to be as closely related to the tiger as possi-ble—which presents a bit of a problem.
    “The thylacine was the sole remaining representative of its family,” Don said. As a species, the Tasmanian tiger diverged from its closest cousin 25 million years ago. Of the sixty or so species of living marsupial carnivores—all of which are potential candidates—none look very much like the tiger. These species include such creatures as the dusky antechinus, a mouse-sized marsupial with a giant-sized sex life (its copulation is described as “violent” and the males all die of stressrelated disease within three weeks of mating); the spotted-tailed quoll, a forest predator that looks like a cross between a cat and a weasel; and the Tasmanian devil, a black-furred scavenger with powerful, bonecrunching jaws.
    “I think it would come down to the devil really,” said Karen. “The devil is the largest of the carnivorous marsupials.”
    Although only one third the size of the thylacine, the Tasmanian devil is a fierce beast. And like the thylacine and all marsupials, the devil gives birth to tiny incompletely developed young, which it suckles in a protective pouch.
    To create this devil of a tiger, the cloning scientists would take an unfertilized egg from a female Tasmanian devil, remove all the devil DNA from inside, and then micro-inject the tiger's DNA into the egg. Then they would zap the egg with an electrical pulse. The egg and DNA wouldfuse, and cell division would begin. Shortly thereafter, they would implant the resulting microscopic embryo into the devil's womb and a few weeks later a tiny tiger would be born.
    Alexis, who had been quiet up to this point, suddenly perked up. “So are you saying