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Today, an article about the tigers in the Swiss newspaper, "Le Temps". Interesting, I try to sum up it.

Introduction: a fact: 97% tigers disapeared since the year 1900 ago. Main factor: the man. Because of 1) hunting, 2) tiger's habitat reduction, 3) their preys's impoverishment, 4) poaching because of the "Chinese medicine".

Development:
The "Current Biology" magazine from the 25/10/2018, published the results of an international study about the tiger's history, its migration paths and its local adaptations. This study is funded on the entire 32 wild or captive tigers' genome. These 32 tigers are representative from the different Asian regions where the tigers are living.

This study confirms there are, indeed, 6 tiger subspecies: South China tiger, Sumatran tiger, Bengal tiger, Indochinese Tiger, Malaysian tiger and Siberian tiger. In 2004, a partial study of this genome already told there were 6 tiger subspecies. But other researchers in 2015 advanced a lower figure, but now thank to this study, the 6 tiger subspecies are confirmed. 6 tiger subspecies in addition to 3 extinct tiger subspecies: Bali tiger, Caspian tiger and Java tiger.

But, very interesting, this study of the tiger's genome reconstitutes the "geological story" of this felid. The oldest fossils date from 2 million years and were located China and Indonesia. But the genome analysis allows only to go back to 110.000 years, thus linked to a weak genetic diversity. End of the Pleistocene era, bad period for the tiger, "genetic bottleneck period" for the tiger that lasted till the end of the last glaciation i.e. 11700 years before JC.
75000 years ago: the super volcano Toba (Sumatra) eruption provoked several winter decades and more than 1000 years cooling of the Earth.
53000 years ago: The Bengal tiger is an isolated subspecy.
45000 years ago: a new East Asian tiger lineage is born. This new lineage split in two: the Malaysian tiger and the Indochinese tiger.
After the last glaciation (11700 years ago I presume ?): birth of the last tiger subspecy, the Siberian tiger.

This study also stresses on 14 strong pressure-submitted tiger's genes. Among these ones, the ADH7 gene, ruling the size of the big cat that ranges from 2,30 meters  (Sumatra tiger) to 3,80 meters (Siberian tiger).

Conclusion: "all the tigers don't look alike" ! Hence the necessity to respect their singularities and to not cross different subspecies. Reply