Re: [Re: Feathered topics.]

[Tony Canning <tonyc@foe.co.uk>]

archosaur@usa.net wrote:
> 
> dbensen <dbensen@gotnet.net> wrote:
> > Here, I would like to stand in and defend Jurassic Park.  Although they
> > did a lot of silly things, the frogs _weren't_ and accident.  The author
> > (I misplaced my book, and I don't know how to spell Mr. C.'s name) put
> > those frogs in there, because, without them, he couldn't plausibly have
> > the dinosaurs change sex.  The whole idea was that the dinosaurs couldn't
> breed because they were all female, but the frog DNA provided them with a
> mechanism that turned some of the dinosaurs into males.  Frogs do make those
> changes, and fish too, but I don't think any birds can, so birds are out as
> genetic donors.  So, the frogs were necessary to the plot.
> > Dan
> 
> +++++++++++++++++++++++++++++++++
> 
> As a die hard JP fan myself, I feel that I am well within my Es/Ex rights here
> when I say that if Chrichton had bothered to do his homework a little more he
> could have used parthenogenesis in place of that silly anuran idea.
> 
> This would be especially advantageous to him, the writer, since all diploid
> reptiles and birds give parthenogenic birth to MALE young.
> 

Er, all the parthenogenetic reptiles I can think of are TRIPLOID giving
birth
to female young. 

In my view, a more plausible plot would have used temperature-dependent
sex
determination - the distribution of this character in diapsids and
anapsids
is consistent with with this being the ancestral state for Reptilia.  A
simple thermostatic malfunction of the JP incubator could then account
for
the appearance of both sexes.

NB, I am not claiming that dinosaurs had TSD, merely that it is more
believable
than compatibility with frog DNA.

Tony Canning