Heh, actually I'm glad that someone else besides me understands that
an adult organism could never be genetically altered the way sci-fi
often portrays. Even if you could introduce foreign DNA to every
cell, it likely wouldn't activate properly, and the developmental
pathways which would have to be reactivated to induce essentially de-
differentiation of the adult tissues so changes could then take place
would more than likely simply be highly disregulated, resulting in
numerous neoplasms. It's very difficult to make already formed
structures change their shape spontaneously to another organized
form.
Now from the single-celled embryo start-point, it might not be as
difficult as we would think. The simple fact is that DNA of most
higher organisms is remarkably similar. In fact, humans share about
75% sequence homology with bananas! It would be a very tedious
process to transfer genes one by one, which is the only way to ensure
proper chromosomal positioning, and one would need to be certain to
include transcription factor genes that are specific for the
structural protein and patterning genes that would create the unique
organism, but from what I've learned in my graduate genetic studies
and indexing of genetics journals, a transfer of less than 1% of
human DNA, a one to two hundred genes, would be enough to create a
furry. The most important change would of course be to cortical
development in the brain. And interestingly enough, geneticists have
found that the alterations between chimps and humans are very
simple. Perhaps as few as two dozen polymorphic alleles are
responsible for the majority of human brain size and complexity.
The main reason humans and animals cannot form viable chimeric
organsisms has less to do with the similarity of gene sequence than
with the actual positioning of those genes on the chromosomes and the
number of chromosomes. For proper mitosis, the sequences of
chromosomes must pair up closely enough to then segregate evenly into
the daughter cells. Even chimp DNA, as closely matched as it is
(99.4% homology), is useless to creating a chimera because the
chromosomal arrangement is different, and chimps have 48 chromosome
instead of 46. Since the extra chromosome has some vital genes,
during the formation of the chimeric embryo, the first cell would
have 47 chromosomes, and the mis-matched sequences would suffer from
non-disjunction and numerous translocations. The cells would likely
get to perhaps the blastula stage, but as structures try to form, the
cells would find that too many lack the right genes while others have
more than a single pair, and thusly embryonic lethality.
This is not the case with gene-by-gene transfer. With sequence-
specific vector systems, it is possible to replace the homologous
gene sequences with a high degree of accuracy. There was recently a
meeting in which geneticists actually discussed human-animal
chimeras. So advanced has the technology become, that the questions
were not about if it could be done, but rather what the moral and
ethical implications are for creating such an organism.
Personally, I feel that even if we were successful to our wildest
dreams and ended up with beings that were utterly flawless, they'd
still have short miserable lives. Can we forget that not more than
40 years have passed in the USA since the civil rights movement? How
humans still hate each other simply on the basis of race? What would
these bigots do to a being that was truly a non-human intelligence?
I can assure you, after having seen many History Channel
documentaries of the Nazi's, the KKK, and other crazed groups of hate-
mongers, that the poor furry creatures would be tortured and killed
most horribly. That is why, even if I do happen to locate all the
proper genes, I cannot create a furry. How can I justify subjecting
an innocent creature to the suffering the human race would inflict
upon it? My own dreams would not be realized then, for I would never
be able to live a peaceful happy life with the beautiful beings of my
dreams. Unfortuately, humans are too filled with hate and foolish
pride and greed. The dream must remain a dream
--- In SkunkworksAMA_at_yahoogroups.com, "Andrew Priest" <apriest_at_n...>
wrote:
> It's a nice thought, isn't it? That but with some human DNA and
some skunk
> DNA you could do the magic mixing thing and make a living version
of the
> trio. I do, however, fear it wouldn't work that way. If the
scientists feel
> that the result of such a crude fusion of human and animal DNA is an
> abomination, well, I'd not be surprised if it was. Even if be some
lucky
> chance you ended up with a viable organism, what would you have
achieved if
> you produced some freakish thing that barely ekes out some months of
> horrible existence before finally succumbing to the inevitable
conclusion; a
> miserable death to end a pitiable life? Perhaps is might be so bad,
but
> we're tinkering where we have no idea. Furries as depicted would,
at best,
> have to be the product of an absolute knowledge of DNA and genetic
> manipulation. They would have to be the result of precise designing
from the
> ground up.
>
>
>
Received on Sat Sep 06 2003 - 02:25:42 CDT