[ad_1]
A new study suggests that there are six distinct subspecies of tigers in the world, not two. These results, according to a report by the New York Times, could offer better advice to conservation groups in hopes of saving the endangered animal.
Before the new study, scientists originally thought that tigers can be classified into five subspecies. Gizmodo wrote that this had changed in 2015 when researchers discovered that the classification of tigers was as simple as dividing them into two subspecies: one on the mainland and another in Sumatra and in other Indonesian islands. In 2017, the International Union for the Conservation of Nature (IUCN) Cat Specialist Group recommended this system of two subspecies as the ideal system to prevent the decline of tiger populations.
Shi-Jun Luo, a researcher at Peking University and lead author of the study, and colleagues at Peking University, however, challenged this direction in an article published in the newspaper on Thursday. Current biology. Compared to 14 years ago, when Luo first introduced his theory that tigers had six living subspecies, the team used newer and more advanced genomic methodologies and techniques to perform a genomic analysis of 32 preserved wild tiger specimens.
New discoveries have confirmed the existence of six subspecies of live tigers: Amur, Bengal, Indochinese, Malayan, South China and Sumatra. Three other subspecies identified for the first time in the 1930s – Bali, Caspian and Javan tigers – have become extinct in the last 70 years.
As noted the New York Timesless than 4,000 tigers currently survive in the wild. This figure is considerably lower than the approximately 100,000 tigers that lived about a century ago, before anthropogenic factors such as poaching and habitat destruction reduced their numbers. One subspecies, the South China Tiger, currently exists only in captivity.
"Three other subspecies of tigers have already disappeared from extinction." https://t.co/sRV5V7LjZo
– Extinguishing symbol (@extinctsymbol) October 28, 2018
The researchers also found that all subspecies of tigers recently had a common ancestor about 110,000 years ago. This creature would have existed in what is now known as Southeast Asia and South China. It is at this point that the species has probably spread to other parts of Asia due to the collapse of the population caused by climate change.
Because of this collapse of the population, all subspecies of living tigers have their own unique genetic characteristics that distinguish them from each other. These include the Sumatran tigers, who were the first to diverge from their common ancestor and possess genes that allowed them to develop smaller bodies than those of other subspecies.
"In India and Siberia, tigers attack large ungulates, but in Sumatra they are more dependent on wild boar and smaller deer. It makes sense that smaller prey exerts selective pressure on the smaller tigers, "said Luo.
In a statement cited by the New York TimesLuo said the work of his team is important because it is just as essential to preserve the genetic diversity of tigers as to prevent animals from disappearing.
"Preserving such genomic signatures, it is preserving the evolutionary uniqueness accumulated by tigers over the course of thousands of years. We must respect this specificity by maximizing our efforts for all subspecies of tigers. "
While Luo and his team think that reclassifying tigers into six subspecies might be more beneficial than the old two-subspecies system, other experts believe that using advanced techniques to analyzing the tiger genome will not have a sufficient impact on the research. save all subspecies of extinction. Ullas Karanth of the Wildlife Conservation Society told the New York Times that the populations of certain subspecies, in particular the Indian and Russian tigers, are "simply too small" to be saved by reclassification.
[ad_2]
Source link
