Posts Tagged ‘species’

Changes in diet lead to changes in morphology and behavior:


These are precisely the same changes that have happened between wild and domestic Canis lupus populations.

Domestic variants are called Canis lupus familiaris.

In the same way that these lizards have evolved to eat vegetation, domestic dogs have new digestive adaptations to consume carbohydrates.

But these does not mean that new species have been created.

In the case of dogs and wolves, there has continued to be a small but not insignificant gene flow between wild and domestic populations. Black wolves in North America obtain their melanism from a mutation that was introduced into their population through breeding with domestic dogs, and now melanistic Italian wolves have been found to have exactly the same mutation that was also introduced in exactly the same way.

I don’t think dogs and wolves will ever become divergent enough to become distinct species, but I do think that smaller dogs, which are genetically isolated from the larger ones, could eventually evolve into a new species.

If there is no gene flow between the lizards on these two islands, they will also eventually become so genetically distinct as to lose chemical infertility.

I should also note that Dawkins hits the nail right on the head when he makes the caveat that we should not automatically assume that the lizards of Pod Kopiste haven’t also experienced rapid evolution as the ones on Pod Mrcaru. They could have indeed experienced similar rapid evolution, but the two would have derived from a common ancestor.

I think some of the problems in doing comparison research on dogs and wolves is that people are unwilling or unable to understand that this possibility exists.

There is an assumption that the wolves we are studying in captive situations are truly reflective of the ancestral population that gave rise to domestic dogs.

Most of these wolves are large wolves from northern Eurasia or northern North America.

It’s very unlikely that any of these wolves has contributed much genetic material to  modern dog populations.  North American wolves haven’t contributed much at all.

Further, most wolves in captivity descend from ancestors that were heavily persecuted by man.

What we’ve done is something like the Belyaev experiment in reverse. Whereas Belyaev selected for lack of fear in foxes, man has selected for something akin to paranoia in wolves.

We’ve trapped and poisoned them across the northern hemisphere.

The only ones that have survived, with the exception of some populations in the high arctic, have been those that have been most overly cautious. It’s well-known that many wolves won’t even cross highways, which stymies their recolonization of much of their former range, and in Yellowstone, at least one “Casanova wolf,” a bachelor wolf that mated only with the non pair-bonded wolves in established packs, used the highway as a buffer zone to keep from being killed by the main breeding male  in the pack.

The wolf that once ranged over the northern hemisphere couldn’t be like these animals. It had to have been much more adaptable and less timorous than these very reactive and fearful animals.

The ancient wolf had to have been an animal that was very easy to domesticate.

I’ve occasionally stolen from an insurance company’s advertisements when I’ve written about these issues, but I do think that dog domestication had to have been so easy a caveman could do it.

Modern wolves, in general, are difficult animals to tame. There are exceptions, and I’ve written about them at length on this blog.

But they are exceptions.

And just because some modern wolves have proven to be quite like dogs when socialized to humans doesn’t mean they are all appropriate pets.

It just means that the analogy that says dogs and wolves are as different as chimps and humans is false one.

You’ll never find a chimp that can do all the things that a human can do, but occasionally, you’ll find a wolf that is as tractable as any retriever or a dog that is as obstinate and reactive as any wolf.

Because some wolves are quite like dogs when they are imprinted and socialized with humans, I think it’s actually much more important to tell people not to keep them as pets.

Just because one tame wolf is as nice as a golden retriever doesn’t mean they all are. In fact, most are not.

But it’s not like the difference between humans and chimps.

It’s really the difference between wild and domestic.

I don’t know why it is that with this one domestic species very intelligent species spend hour after hour trying to deny the proper classification with its wild ancestor.

It’s almost creationist in a way.


I should also note the wall lizards have been introduced to southwestern Ohio. One of the members of the Lazarus department store family introduced a few lizards to the Cincinnati suburbs from Italy, and the wall lizards have expanded their range into adjacent Kentucky and Indiana.

Because they were introduced by a member of the Lazarus family, they are called “Lazarus lizards.”

I wonder if these lizards have any unique adaptations that separate them from the ones in Italy.




Read Full Post »

What is this animal?


Leave your guesses in the comments.

Answer coming soon.

Read Full Post »

%d bloggers like this: