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Posts Tagged ‘Chinese wolves’

Let’s say you’ve been asked to identify a tree.

And all you’ve been given are two twigs.

You might get it right.

If you’re educated, you might get within the right genus, but getting the exact species is probably next to impossible.

Now, let’s say someone gave you a log and asked you to do the same thing.

Logs are a bigger part of  the tree.  They have bark, and you can examine the hardness and texture of the wood.

You are much more likely to get it right.

Currently, there is a debate between geneticists about the origin of the domestic dog. One school, which uses studies mtDNA and y-chromosomes, say that dogs have origins in either southern China or Southeast Asia.  The other, which has examined nearly 50,000 SNP’s (single-nucleotide polymorphisms) within the dog genome and found that dogs are most similar in their genome to Middle Eastern wolves.

The ones who are looking at mtDNA and y-chromosomes are looking at twigs.  They are but a tiny fraction of the genome compared to the 50,000 SNP’s.  All mtDNA does is trace maternal heritage, and it’s possible to get severe errors with it, such as under-estimating when savanna and forest elephants split or diving the Indian wolf a separate species.  The exact same errors can be made with y-chromosome analysis. The only difference is that y-chromosome analysis looks at paternal heritage.

That’s why I’m generally dismissive of the new studies (this one and this one) that say dogs are derived from Southeast Asia or East Asian wolves. There are no Southeast Asian wolves, except for a few that live in Myanmar (Burma), so it’s always been a very silly thing for people to puff up about.  Except for those Burmese wolves, there have never been Canis lupus wolves in Southeast Asia, but there have been golden jackals and their relativels. Similarly, Southern China is on on the periphery of the wolf’s range– and always has been.

The landmark study of dog and wolf nuclear DNA was performed at UCLA.  Peter Savolaninen, who is the major proponent of the theory that dog originated in East Asia, complains that this study didn’t include any wolves from south of the Yangtze. It didn’t need to. It included dingoess, which have origins in Southeast Asian domestic dogs. They take the place of that much harder to procure sample.

The problem with these “twig” studies is they are much easier to perform and analyze than the genome-wide analyses.

I’m much more willing to trust a study that used a “log” than one that looked at “twigs.”

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Mark Derr performs a devastating take-down of the theory that dogs originated in East Asia in How the Dog Became the Dog.  He points out that the time period for which dogs supposedly originated in East Asia does not correspond with any archaeological data. Dogs don’t appear in that part of the world until thousands of years after they appear in other parts of the world.

Now, just because dogs appear to be most closely related to Middle Eastern wolves does not mean that they became morphologically distinct from wolves there.  Derr wrote that the first morphologically distinct dogs would be found in Central Asia– and just a few months later, a 33,000-year-old skull of wolf with domestication features was discovered in the Altai Republic.

It’s also an error to look for an origin time and place for domestic dogs. It actually involved relations between people and wolves that took place over tens of thousands of years.  Middle Eastern wolves were the basis for most dogs we have today, but some of those from East Asia– including the dingo– do show some influence from Chinese wolves. Some European breeds show some influence from European wolves.

 

 

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