It is something of a cliche that DNA and genetic manipulation is the future of human medicine. However true that proves to be we will see. But DNA testing and manipulation is certainly a major key in the struggles to prevent extinction – and perhaps reverse it. It is also a major player in the control of all sorts of pests and invasive species.
Recently we talked about efforts to use DNA sequencing and genetic engineering to try and reverse extinctions. We have also talked about discoveries that may allow humans to control ticks by altering their genes. Australia is considering genetic warfare against a number of invasive species.
Today the topic is tiger pawprints in Sumatra and how those prints may help protect the isands highly endangered tigers.
Since 1900 tigers have gone extinct on Java and Bali. The Caspian tiger is also gone and the South China tiger is gone or nearly so. Tigers are found in about a dozen countries and are now considered to be two subspecies. Continental tigers (Panthera tigris tigris) and Sunda tigers (Panthera tigris sondaica.) The Sunda tigers are now only surviving on Sumatra. There are approximately 400 of them left in the wild.
The future of the tiger in the wild is mixed. There may be tigers in about a dozen nations but populations in Vietnam Laos and Cambodia are tenuous at best. Some countries, such as Nepal, may have doubled their populations. India has had major success at increasing tiger populations, it it may be at the cost of other vulnerable animals. To date, counting tigers is based on visual sightings, camera traps, finding scratch marks and other less efficient tools.
Now comes another tool in the battle.
San Diego Zoo researcher Mrinalini Watsa has made a major advance using DNA testing and a cell phone app. It’s quite simple. She used a Sumatran tiger living at the zoo as a test subject. She was able to scoop up soil from a pawprint, find tiger DNA in the pawprint and transfer infomation to a cellphone. According to CNN she is refining the technique to be able to identify gender before testing in the wild.
The breakthrough has serious implications. Previously researchers could only count pawprints and make a rough estimate of the tigers in a given area. Now they can be far more accurate about the number and gender of the animals present and what they are doing.
Watsa is a reseracher in population sustainability and focuses on Sumatran tigers. Her research goals are to develop low cost investigational tools to help protect the tigers, according to the zoo website.
It is also a fact that there a very likely many more tigers in captivity than there are in the wild. The Wild Animal Sanctuary (TWAS) recently rescued six who were in captivity as a tourist attraction on Guam. Such tigers are not considered too important in the war on extinction. They are usually mixed breed tigers and not representative of a specific subspecies.