Nova-explores how and why dogs evolved from wolves in less than 10,000 years

[0roo0roo]

Nova
Dogs and More Dogs
60 mins.

?Dogs and More Dogs? explores how and why dogs evolved from wolves in less than 10,000 years, and why (scientifically speaking) they hooked up with people. Their domestication, it seems, was wolf-inspired: they learned that if they stuck close to humans, they'd be fed. And their diversity (400 breeds) stems from the various things that people had some---but not other---dogs do. And why do people like dogs so much? ?They're very good at showing they like us,? says James Serpel of the University of Pennsylvania's School of Veterinary Medicine. John Lithgow narrates.

http://www.pbs.org/wgbh/nova/dogs/


pretty interesting, esp the part where a russian scientist breeds 10 generations of wolves and selects for friendliness, and ends up not with only tame wolves, but drooping ears, different coloration etc....

i'm sure you can find repeat showings on tvguide.com.. maybe the pbs site or your local pbs station site. was on today, but tvguide.com shows repeats for my area atleast. and well pbs has digital stations that do encores too. http://www.pbs.org/digitaltv/localstation.htm

damnit, 5 digital channels in my area http://www.kqed.org/tv/digitaltv/index.jsp gotta get hdtv or a hd card

 

[Excelsior]

Funny you should mention this, I was flipping the channels and saw this on. I found it pretty interesting. I hated the geneticist from UC Berkley cause he didn't like dogs.

 

[0roo0roo]

Interestingly, many of the morphological and physiological differences that exist between dogs and wolves may not have been intentionally selected for by humans, and could have been a result of selection for tameness in dogs. An experiment which involved Siberian foxes (Vulpes vulpes) demonstrates how this could have happened (see Trut, 1999 for a review). The experiment was started in the 1940's by the Russian geneticist Dmitri Belyaev, who studied the process of domestication using a population of fur farm foxes (see Fig. 1). The foxes used in the beginning stages of the experiment were difficult to handle, very afraid of people and generally behaved like wild animals. The experimenters began to selectively breed the foxes for one trait - tameness around people. At the age of one month, an experimenter would offer food to each fox kit while trying to pet and handle it. This was done twice - while the kit was alone and while it was with other fox kits. This routine was repeated monthly until the kit was seven to eight months old and at that point, each kit was assigned to one of three classes based on how tame it was. Class III foxes attempted to flee from experimenters or tried to bite them. Class II foxes were not friendly to the experimenters, but allowed themselves to be touched. Class I foxes were friendly towards the experimenters and would often approach them. After six generations of breeding only tame foxes, a new class, Class IE, ("domesticated elite") had to be added. These foxes were very dog-like and actively sought out human attention and would lick experimenters and wag their tails like dogs. After twenty generations, 35% of the experimental foxes were domesticated elite and today, 70-80% of the foxes are.

-A photo of a captive silver fox, Vulpes vulpes.

Since the foxes in the experiment were being selectively bred for a behavioural trait (tameness), the experimenters hypothesized that physiological changes in the systems governing the fox's hormones and neurotransmitters would also occur, as an animal's behaviour is often mediated by these chemicals. Indeed, that is exactly what happened. As the experiment proceeded, a steady drop in the hormone producing activity of the domestic fox's adrenal glands was measured. For example, after several generations of selective breeding, the basal level of corticosteroids in the blood of the domesticated foxes was far lower than that of the control group of non-domesticated foxes. Changes in the neurochemistry of the domesticated foxes was also noted, as they had higher levels of serotonin in their brains compared to the control group of foxes.

After several generations of selecting for tameness, new traits only rarely seen in wild foxes began to become more common in the domesticated population. For example, after ten generations, several of the domesticated foxes had piebald coloured or brown mottled coats. Later in the experiment, it was noted that several of the tame foxes had floppy ears, short tails or curly tails. Even later, changes in the skull morphology of the foxes was noted as well, as skull measurements showed that the cranial height and width of the domesticated foxes tended to be smaller than those of control group foxes. The domestic foxes also had shorter and wider muzzles than the control group ones.

Many of the differences between the domestic foxes and the wild foxes are similar to the differences seen between domestic dogs and wolves. Wolves do not have floppy ears, curly tails, or piebald coloured coats, but many dogs do. Skull size is also one of the main ways dogs differ from wolves and selecting foxes only for tameness changed their skull size. The results of this experiment seem to suggest that many of the unique characters seen in dogs and not wolves are a result of the selection of dogs for tameness. But, how does selecting animals for a behavioural trait change their overall morphology like this? It has already been noted that selecting animals for a behavioural trait can change the amount of hormones and neurotransmitters produced by the animals because an animal's behaviour is often controlled by such chemicals. The early development of an animal is also, in part, controlled by these chemicals, so a small change in the animal's endocrine and neurochemical systems may result in changes to the early development of the animal.
http://www.ualberta.ca/~jzgurski/dog.htm
the pbs nova site doesn't really go into any detail that was in the show

 

[Redviffer]

Thanks for the heads up, I'd like to catch this and tape it for my kids. They are going through a pet phase: hamster, guina-pig, cat, dog, and hopefully nothing bigger.

 

[dighn]

Originally posted by: Excelsior
I found it pretty interesting. I hated the geneticist from UC Berkley cause he didn't like dogs.

i don't like dogs, do you hate me?

 

[Czar]

very interesting, want to see that show now, damnit

 

[Excelsior]

Originally posted by: dighn

Originally posted by: Excelsior
I found it pretty interesting. I hated the geneticist from UC Berkley cause he didn't like dogs.

i don't like dogs, do you hate me?

Yes, I hate you with every part of my being.

 

[jjones]

"The dingo ate your baby!"

 

[Kenazo]

John Lithgow, huh? Wasn't he the dad from 3rd rock from the sun? Great, an alien is telling us what to believe about our beloved pets.

 

[Kadarin]

They shouldn't say "evolve", because every decent, God-fearing Christian knows that the silly "Theory of Evolution" is wrong and that Creationism is right and that the Lord created dogs as they are 6000 years ago and that shows like this make the baby Jesus cry.

 

[Bassyhead]

i've seen something like this before, it's pretty interesting. is this the first time that nova episode aired?

 

[Quixfire]

It still doesn't explain how the Klingons evolved so fast.

 

[Kadarin]

Originally posted by: Quixfire
It still doesn't explain how the Klingons evolved so fast.

I'll go with the baby Jesus theory on that one, too..

 

[KLin]

Originally posted by: Quixfire
It still doesn't explain how the Klingons evolved so fast.

wasn't a larger makeup budget the verdict on that discussion?

 

[Amused]

If selective breeding can have that dramatic an effect on dogs in such a short time, what kind of effect has slavery and the selective breeding that comes with it had on humans?

 

[Fausto]

Originally posted by: Amused
If selective breeding can have that dramatic an effect on dogs in such a short time, what kind of effect has slavery and the selective breeding that comes with it had on humans?

Not much I'd say since the time period was much shorter although you certainly could breed larger, stronger humans if you wanted to.

 

[tk149]

Michael Crichton's "Congo" comes to mind...

 

[0roo0roo]

-

 

[0roo0roo]

Thursday, 5 4:00 AM Nova: Dogs and More Dogs 9 KQED
Friday, 6 3:00 PM Nova: Dogs and More Dogs 6 KVIE
Sunday, 8 12:00 PM Nova: Dogs and More Dogs 9 KQED

 

[MAME]

uh, that is a flat out lie. God made them seperately. Enough with this evolution nonesense

 

[Kev]

weird, i was thinking about this subject today for some reason (not nova, about how dogs evolved so quickly).

 

[Fausto]

Originally posted by: MAME
uh, that is a flat out lie. God made them seperately. Enough with this evolution nonesense

FlameTech Rating: 3 (of possible 10).

 

[MercenaryForHire]

Originally posted by: Fausto

Originally posted by: MAME
uh, that is a flat out lie. God made them seperately. Enough with this evolution nonesense

FlameTech Rating: 3 (of possible 10).

<Really Fast Announcer Reading Fine Print>
All FlameTech ratings are subject to further user and moderator intervention. Only you can prevent forum fires.

- M4H

 

[StageLeft]

Originally posted by: Fausto

Originally posted by: Amused
If selective breeding can have that dramatic an effect on dogs in such a short time, what kind of effect has slavery and the selective breeding that comes with it had on humans?

Not much I'd say since the time period was much shorter although you certainly could breed larger, stronger humans if you wanted to.

Already been done. They're called Canadians. *SWOOSH*.

Anyway, what sort of developmentally challenged scourge on humanity doesn't like dogs?

 

[MercenaryForHire]

Originally posted by: Skoorb

Originally posted by: Fausto
Not much I'd say since the time period was much shorter although you certainly could breed larger, stronger humans if you wanted to.

Already been done. They're called Canadians. *SWOOSH*.

:beer:

- M4H