As if sleeping, she lay peacefully on her side. Her legs were tucked in close to her body, and she still felt warm as I gently patted her on the head. Half-closed, her eyelids partially covered her ocean blue eyes and her soft creamy white fur tempted me to cuddle up next to her. She was a 350-pound white tiger, and during the night she had peacefully died in her sleep. With approximately only 200 white tigers in the United States, an autopsy was being connected to determine the cause of her death.
White tigers are not their own species of tiger; they are white-colored Bengal tigers. They are not albinos either; they have a pink nose, creamy white fur with black / brown stripes, and blue eyes. White tigers only occur when two tigers mate and both carry the gene for white coloring. I assisted the veterinarians in stretching out her nine-foot long body as the chief veterinarian made a small belly incision in order to explore her vital organs. While examining the tiger, the doctor prepared several of her vital organs for testing by sealing them in small sterilized containers. As I sat next to the tigers head, the doctor looked up from his patient and said, Hold this. As if he was holding a Ming vase, the doctor carefully rested a warm fleshhy sphere into my palm. You are holding over a thousand white tigers in your hand. He said.
While continuing his examination he added, That is one of her ovaries, and it may one day save this entire species from extinction. Mammals such as the tiger have thousands of surplus egg-cells in their ovaries, and males have millions of sperm cells in their testes. If accessed, these gametes as they are scientifically called, can be utilized to radically increase the breeding potential of an individual animal.
This is the future of endangered species recovery and survival. Assisted Reproduction Technology is a new conservation tool that has the potential to play a decisive role in reversing the brightness of our most endangered wildlife species. Assisted reproduction technology such as artificial insemination, embryo transfer and invroit, or test-tube fertilization represent is a powerful means for the recovery, storage and use of viable gametes from both live and recently faded animals. Embryos produced by invitro fertilization, test- tube tigers for example, can be transferred to recipients of the same or nearly related species, or cryopreserved; frozen and stored for later use. Essentially, the endangered animals are able to breed long after they die.
Organizations such as Gamete Recovery International aim to recover gametes and other biomaterials from animals which die in captivity as a conservation tool for research purposes and the maintenance of genetic diversity within threatened populations. A network (of participating institutions such as national parks, reserves, zoos and breeding farms), has established access to the genetic material of rare and endangered species that die in their facilities. Several South African wildlife organizations have already collected and banked biological material from cheetahs, black and white rhinos, dolphins, wild dogs and sable antelope. Through this project, viable genetic material from dead endangered wildlife is recovered and recycled back into the wild. This technology minimizes the impact that the loss of an individual member can have on the rest of its already thinning population.
Assisted reproduction technology not only has the potential of saving endangered populations, but it also preserves genetic diversity. When an animal is rescued from extinction at the last perilous minute, only a fraction of its genetic diversity remains. Genetic diversity is what makes every individual different. Every animal that sexually reproduces contains its own personal mix of genes. To quote EO Wilson in Biodiversity (1988. Washington, DC: National Academy Press).
The number of genes range from about 1,000 in bacteria and 10,000 in some fungi to 700,000 or more in many flowering plants and a few animals. A typical mammal such as the house mouse has about 100,000 genes …. If stretched out fully, the DNA would be roughly one meter long. But this molecule is invisible to the naked eye …. The full information contained therein, if translated into ordinary-size letter of printed text, would just about fill all 15 editions of the Encyclopedia Britannica published since 1768.
This tremendous variation within a species allows its installations to adapt to changes in climate and local environmental conditions. In addition, genetic diversity can be critical in controlling disease.
Genetic diversity boosts American farms total crop values by over $ 500 million a year. Without a constant blend of new resilient genes into our crop species, pests and diseases could soon become rampant. Genetic diversity provides a constantly evolving defense against invaders, more so than pesticides can provide. Over 400 species of crop pests have already developed a resistance to one or more of the pesticides used to control them.
Due to human overpopulation, many wildlife populations are becoming fragmented and spread over wide distances. Highways, fences, and buildings constructed to make our lives easier, division animal territories.The Florida panther, for example, is at a genetic bottleneck. Due to fragmented territory and population loss, the immigration and emigration from neighboring subspecies of mountain lions has stopped. This isolation creates little or no genetic exchange between them. Unable to refresh the gene pool, the only diversity is mutation. Mutation can be important to genetic diversity but it rarely produces positive results.
In addition to auto collisions, which account for 49% of documented Florida panther deaths, inbreeding within the species has added to the population reduction. Low semen quality, lowered fertility, and a decrease in cub survival have played a huge role in limiting the Florida panther population to only 50-60 individuals. This has also happened to the cheetah population in Africa. The effects of Florida panther inbreeding are also clearly visible. Many panthers have kinked tails and a cowlick, or whorl of hair in the middle of its back. These are believed to be results of recessive genes being expressed through inbreeding. Assisted reproduction technology may be one solution to the Florida Panthers problem. Breeding the Florida panther with other cats of the species, so freshening the gene pool, may increase their reproductive potential. This has been tested on some panthers with limited success but the potential still remains.
As for the white tiger, when the veterinarians concluded their examination that they were still unable to find her cause of death. Her organs were immediately sent to a laboratory for further testing, while her ovaries were prepared for safe storage. After my final goodbye, I gently slid my hand over the tigers soft face, forever closing her ocean blue eyes, while her countless future offspring slid into a foggy cryogenic chamber awaiting the day of their birth.