[sci.bio] baby dodo

A.S.Chamove@massey.ac.nz (A.S. Chamove) (11/14/90)

My question is why is it not possible to recreate extinct animals?

In the simplest situation, when samples of moist tissue remain 
(as is the case with the Mastodon where frozen bits have been found
in the far North), why cannot the DNA be removed from a cell and 
implanted into an ovum and carried by a related creature (elephant
in this case)?

In the case where only dry bits remain (the bones of Australopithecus or the dry skin of the Dodo or Moa or Passenger Pigeon),  are there
active or recoverable strands of DNA which could be comparably
removed and implanted into a living ovum?

arnold
new zealand
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kuento@kuhub.cc.ukans.edu (11/15/90)

In article <1990Nov14.005513.28666@massey.ac.nz>, A.S.Chamove@massey.ac.nz (A.S. Chamove) writes:
> My question is why is it not possible to recreate extinct animals?
> 
> In the case where only dry bits remain (the bones of Australopithecus or the dry skin of the Dodo or Moa or Passenger Pigeon),  are there
> active or recoverable strands of DNA which could be comparably
> removed and implanted into a living ovum?
> 
> arnold
> new zealand

They're working on it! I know of some published analyses of bits and
pieces of genetic material from extinct plants/animals...the problem
with "reconstruction", however is just that: all we can get are bits
and pieces. In order to *truly* reconstruct a critter, we'd need to
get all the chromosomes, with all the genes, all in their proper
arrangements...I hate to be a naysayer, but I just don't see how we'll
ever be lucky enough to get such a complete genetic package for any
long-dead organisms. The frozen mammoths seem to be the best bet for
a near-complete set, and it wouldn't surprise me to see someone raise
a baby quasi-mammoth in the next 10 years or so (i.e., a baby elephant
carrying some mammoth genes), but I can't imagine much beyond that
sort of scenario. Too bad, indeed.
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Doug Yanega        (Snow Museum, Univ. of KS, Lawrence, KS 66045)
My card: 0 The Fool         "UT!"          Bitnet: kuento@ukanvax
"This is my theory, such as it is....which is mine. AAH-HEM!"

sarima@tdatirv.UUCP (Stanley Friesen) (11/20/90)

In article <1990Nov14.005513.28666@massey.ac.nz> A.S.Chamove@massey.ac.nz (A.S. Chamove) writes:
>My question is why is it not possible to recreate extinct animals?

Mostly because a 100% intact genome is necessary.

>In the simplest situation, when samples of moist tissue remain 
>(as is the case with the Mastodon where frozen bits have been found
>in the far North), why cannot the DNA be removed from a cell and 
>implanted into an ovum and carried by a related creature (elephant
>in this case)?

Because DNA is a rather 'unstable' long-chain polymer that begins to break
down shortly after death.  Thus even the 'quick' freeze that preserved the
Mammoths &c. has allowed the DNA to degrade too far for full reconstruction.
[The meat is actually rather rotten in these frozen carcasses, far too
decayed for intact DNA.  I suppose with a giant cmputer, and lots of patience,
you could reconstruct the intact DNA from the bits and pieces in the millions
of cells in the carcasses, but that is *lots* of work].

>In the case where only dry bits remain (the bones of Australopithecus or
>the dry skin of the Dodo or Moa or Passenger Pigeon),  are there
>active or recoverable strands of DNA which could be comparably
>removed and implanted into a living ovum?

Probably not, these hard tissues are mostly non-cellular even in *living*
organisms, so they never had much DNA to start with.  (The skin of the Dodo
might include the dermis (the living layer), but I doubt it)
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uunet!tdatirv!sarima				(Stanley Friesen)