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Posts Tagged ‘Qinling panda’

giant panda

Giant pandas are the last survivors of their entire lineage of bears.  The Ailuropodinae were once a diverse, mostly omnivorous lineage of bears that were widespread throughout Eurasia and North America during the Miocene.  About 2 million years ago, one extant line of these bears began to adapt to more herbivorous diet, and we believed that this shift to a more herbivorous diet was directly analogous to becoming a bamboo specialist.

The truth is no one ever looked at the carbon isotopes in ancient and modern panda remains to see exactly what when giant pandas became bamboo specialists. Well, a study just published in Current Biology has revealed something quite shocking.

The authors did look at the isotopes in several ancient pandas, including the modern species, but what they found was that the shift to a more vegetarian diet was probably accomplished by the Pliocene.

However, the bamboo specialization did not become established in modern pandas until between 5,000 to 6,000 years ago, roughly about the same time as the rise of the Indus Valley Civilization and the Ubaid Period of Mesopotamia.

This finding has some interesting implications. One is that specialization can happen relatively rapidly in the evolution of mammals.

The other is that specialization can be quite disastrous for a species. Evolution has no grand design, and if there were some kind of foresight in the whole enterprise. giant pandas would have been better of living generalist herbivores.

It is also not really clear what pushed giant pandas into this specialization. Maybe there was a massive range expansion of ungulate herbivores into their forests that pushed them towards that diet.  Maybe there were some human-related factors that led to this specialization.

The truth is we don’t know.

I do, however, have a big question:  Did the Qinling panda evolve the bamboo-specialist diet at the same time as other giant pandas?

The reason I ask is that full genome comparisons revealed that Qinling panda diverged from the other giant pandas 300,000 years ago?

That means that these two forms of giant panda split from each other long before this bamboo specialization. It seems to me that they would evolved this bamboo specialization independently of each other.

There are also fewer studies on Qinling pandas. There aren’t as many studies on this form of panda, and it might not be as bamboo-specialized as the most common form.

Very real conservation implications could come from this discovery.  This discovery means that we should be looking more carefully at the Qinling panda in the wild to see if its diet really is different. This study included only modern pandas from Sichuan, so it would be quite interesting to see what wild Qinling pandas isotopes are like.

So, yes, this is an amazing find, but it has very real implications for panda conservation. It could potentially add more evidence for the Qinling panda as a distinct (and thus very endangered) species if it is found that Qinling pandas have a more diverse diet.

And if they have the same diet, then this diet evolved in parallel between the common giant panda subspecies and the Qinling panda.

Which is pretty amazing that both extant forms of panda bet on this same limited niche.  And this is an odd fate for what were once wildly successful omnivorous bears across the Northern Hemisphere.

Evolution takes us on weird journeys, doesn’t it?

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