ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)

[GrizzlyClaws]

(03-23-2019, 08:37 AM)Sanju Wrote:

(03-23-2019, 12:29 AM)GrizzlyClaws Wrote: However, the genetic study that is quite certain that the modern Sunda tiger also shared a common ancestor with the modern Mainland tiger as recent as 75 kya, then the aforementioned graphs were likely accurate about the whole context.

If, Java and Bali islands were connected with sumatra in glacial maximum, then this founder wanhsien population might have again colonised and bred with ngandong to form bali and javan tigers. So, that there is mainland tiger shared ancestry still existed in all sunda tigers still in 75 kya.

(03-23-2019, 12:29 AM)GrizzlyClaws Wrote: Javan tiger: pure biological descendant of the Ngandong tiger, but exposed to the insular dwarfism

Bali tige: pure biological descendant of the Ngandong tiger, but also exposed to the insular dwarfism

Sumatran tiger: mixed descendant of the Ngandong tiger and the post-eruption mainland tiger (Wanhsien tiger) population

That's the likely theory for the evolutionary lineage for the modern Sunda tiger.

Oh ! if this is true, then I find 2 spp classification inaccurate. There must be "3" spp with sumatran in one clade and bali and javan together in one clade.

Can you please give me PDF about that phylogeny which you referred?

But the big question:

After Toba super volcanic activity, wanhsien radiation supposed to be the only one to survive and expand, how come ngandong tiger survived that catastrophe this to result in 3 spp of sunda tigers?

If they survived to do that, Ngandong tiger who formed by insular gigantism undergone insular dwarfism may be because of extinction of mega fauanal prey which maintained large ngandong tigers but adaptive direction shifted as soon as large prey extinct after eruption and left this tigers to lower their body mass according to prey.

So, I think climate and geography or habitat didn't play much role as they are unchanged after and before.

Now it is about theories.

It is possible that not all local Pleistocene tiger population in the Sunda Shelf died out after the Toba eruption, and the remaining population managed to survive.

When the ecosystems had been recovered after few millennia, another large influx of Mainland tiger managed to migrate to the western part of the Sunda Shelf. The eastern part might be relatively more isolated, thus the Sunda tigers over there were pure, whereas in the western part the Sunda tigers managed to interbreed with the Mainland tiger, therefore the hybrid tiger population like the Sumatran tigers were created.


BTW, the difference between the Javan tiger and Bali tiger were only geographical, since they only isolate from each other for few thousands years, so it was not enough to be considered as two separated subspecies. Reply