Mark Stephen wrote:
> Jon Schild wrote:
>>
>> ilya2@[EMAIL PROTECTED]
wrote:
>>> Has anyone ever written a story about aliens who take over Earth, and
>>> regard humans as "charming wildlife"? I know there are stories where
>>> humans are *pests* living in an alien environment, but what I am
>>> asking about are stories where the top dogs of said environment
>>> actually *like* humans, and take some steps to ensure our survival --
>>> but not to the point of leaving our planet to us. IOW, the way many
>>> suburbanites view raccoons.
>>
>> There is one I read not too long ago, but for some reason can't
>> remember much about. The humans were kept in pens and used as horses
>> by the rather small aliens. Not quite charming wildlife, but not
>> exterminated either.
>>
>
> Not the same story, but in Jack Vance's _Dragon Masters_, humans and
> aliens breed their captives selectively to produce weapons, draft
> animals etc.
>
> I'm a little surprised this idea never comes up in the interminable
> evolution threads. I have three dogs, a border collie, an Irish
> flat-coat retriever and a Great Pyrenees. They differ wildly in size,
> appearance, temperament and intelligence, and these traits seem to have
> been established in only a few generations. AFAIK, the only sf novel
> with a cultural background which would allow this sort of
> experimentation on humans by humans was _Iron Dream_, but is this sort
> of selective breeding with humans actually impossible, or merely
> unethical and kinda disgusting?
>
I was watching a nature show recently about dogs (forget the
actual title, sorry!), and they said that one of the
reasons that there is such a wide variation in dogs, in a
relatively short time frame (80% of the recognized breeds
today didn't exist before 1900) is that dogs have "slippery"
DNA. Apparently dogs have a lot of repeating sections of
DNA, and how many repeats there are has a dramatic impact on
a dogs appearance. For example, the different sizes
(chihuaha, lab, Great Dane) depend on the number of repeats
of a specific section of DNA. Other animals have repeating
DNA. For example, I believe that the severity of one of
the inherited birth defects... cerebral palsy, maybe...
depends on the number of repeats of a particular section of
DNA. The more repeats, the more severe the symptoms.
However, they do not have as many of them as dogs do. So
the short answer is: yes, you can selectively breed for
traits with other animals, but no, you will probably never
get the variety you do with dogs.
Rebecca
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