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Archive for July, 2010

Analyses  of African wild ass MtDNA have confirmed the identity of one of the ancestors of the domestic donkey.

It turns out that the very rare and possibly extinct Nubian wild ass is the ancestor of one the two genetically distinct groups of domestic donkey.

The ancestor of the other genetically distinct group is unknown, but it has been confirmed that the mostly solitary Somali wild ass is the ancestor of neither of these two groups. The exact identity of this other group is still up for  speculation, including some “wild ass” guesses.  (If you don’t like these jokes, then you probably think I’m an ass after reading this post.)

These studies confirm that the first domestication of the donkey occurred somewhere in North Africa around 5,000 years ago.  This finding is pretty interesting, because no other large African mammal has been domesticated.

What’s more is that the researchers found that domestication was an ongoing process. The Nubian wild ass was domesticated several times, and there was always a gene flow between the wild and domestic populations.  This finding is not entirely different from what we’ve found out about dog and wolf populations.

Now, the identity of the other ancestor of the domestic donkey is still a mystery. This is not actually all that unusual. We still do not know which population of wild mouflon is the ancestor of the domestic sheep and the feral European mouflon. In fact, it has only been recently that the European mouflon has been recognized as a feral sheep and is not part of Europe’s native fauna. The exact ancestral wild sheep is probably extinct.

And in this way, donkeys and sheep share a history. The Nubian wild ass is often thought of as extinct in the wild. No one has seen one since late the 1990’s.

But because it went extinct only recently, we can make comparisons using DNA extracted from recently deceased specimens.

It is certainly interesting that the MtDNA studies found this relationship. I am very curious about the identity of the non-Nubian wild ass-derived donkeys. I have not seen the study, and I am wondering whether Asian wild asses might be that ancestor.

I honestly don’t know whether onagers and kiangs can hybridize with domestic donkeys or whether these hybrids are fertile. I also don’t know whether all the different species of ass were included in that study or if all the different subspecies of African wild ass were included. I have not seen the study, but if one of my very well-connected readers could find it and send it to me, it would be very nice.

Of course, one must be careful with reading too much into MtDNA studies. MtDNA may be least prone to mutation, and it is very useful in tracing matrilinear inheritance.  However, it is only one part of the genome, and there are no genome-wide analyses of the donkey. MtDNA is but one part of the genome. It’s useful for its purpose, but one must be careful in reading too much into it.

Remember, the MtDNA studies in domestic dogs strongly suggested that they were derived from East Asian wolves, specifically a South Chinese population. The genome-wide studies found that this simply was not the case.  Using SNP-chip technology, it was found that Middle Eastern wolves were much more similar to domestic dogs than an East Asian population of Canis lupus.

So these are interesting findings, but we need to be cautious about accepting this finding as the final proof.

Still, it shows how important donkeys were in the founding of civilization. We Americans like to think our civilization was built on the back of a horse. It is true. However, world civilization has mostly been built on the back of the donkey.

Where I live donkeys are kept for one purpose: livestock guardians.

One can drive down any rural road in West Virginia and come across small herds of beef cattle. Usually standing in the midst of those cows is a donkey. The donkey’s job is to keep the coyotes and stray dogs out of the pasture– a job they would take seriously even if there were no cows there.

As a general rule, donkeys hate anything that looks like a dog.

The next time I see one of these guard donkeys, I’m going to think of their wild North African ancestors– one extinct and the other unknown. I’m going to think of the ancient civilizations that relied upon these animals to build their marvels and to grow the grain that fed their populations.

I’m going to salute the donkey. I’m going to look at it with wonder.

We would probably be nothing without them.

And now that we no longer need them in my part of the world, it is good to know that they are being put to some use. Guarding livestock from canine predators is really not that hard compared to being a beast of burden, as they are in so many parts of the world.

Compared to their counterparts in poorer countries, most American donkeys have it good.

And that’s no wild ass speculation.

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I wrote about this in my mara post.

Source.

Maras will raise their babies communally.

However, females will allow only their offspring to nurse.

So you do get tense situations when the guard changes at the crèche.

***

This story reminds me of a documentary on sheep I saw a few years ago.

This Scottish shepherd had a ewe that had given birth to three lambs, but because these were hardy Highland sheep, he didn’t want to nurse a lamb and turn it into a pet.

One of his other ewes had given birth to the usual twins, but one of these twins died shortly after birth. The ewe had nurse the lamb and was bonded to it, but it just died.

Ewes will not nurse lambs that are not their own, so the extra lamb that the other ewe had could not be fostered without some innovation.

The shepherd skinned the dead lamb, and then he dressed the third lamb in its pelt.

The foster ewe thought the third lamb was her baby, and she allowed him to nurse.

The third lamb continued to wear the skin of the deceased for a day or two. By then the third lamb had drank enough of its new mother’s milk to smell right.

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Source

This clip shows how three species of antelope utilize acacia trees.

The dik-dik gets to eat only the leaves at the lowest level.

The impala gets the leaves that are at the middle levels on the tree.

And the bizarre gerenuk can eat the leaves from the higher branches.

In this way, three species of antelope are able to utilize the same resource without become direct competitors.

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The answer.

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I’m tweetin’

Yes, I know I have an old twitter account, but I am starting a new one for this blog.

Please use this one.

The “twi” just means twitter. It wouldn’t let me have more letters.

I’m unsure of how twitter is supposed to improve the blogging experience.

But it’s worth a try.

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Source.

This is a relatively young puppy.

It’s unusual to see such a young puppy swim without flailing its front legs in the water.

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Check them out.

The big news is that an otter civet has been filmed. I had only read about this creature. I have never seen a photo or anything other than a crude sketch of one. To see one on film is quite remarkable.

The Sunda stink badger is actually not a badger. It is one of two Old World skunks. The other is the Palawan stink badger, which lives in the Philippines.

All the animals mentioned in this piece, save the Sunda stink badger, are Feliform carnivores. Civets and mongooses are more closely related to cats than they are to Mustelids (weasels, mink, otters, polecats, martens and badgers). Civets are closely related to Hyenas. Hyenas are actually more closely related to cats than they are to dogs.

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