Re: Why Sex ?

Philos Anthropy (anthropy@inwave.com)
Thu, 18 Dec 1997 14:12:38 -0600


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Berrie Staring wrote:

> Thanks for using NetForward!
> http://www.netforward.com
> v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v
>
> (sorry for the horrible spelling)
>
> Anders wrote:
> >
> > I'm not sure, but I don't see any big benefit from the selfish genes
> > perspective with hermaphrodites; the child is still a mixture of the
> > parent genomes. But I think I'm missing something obvious here...
> >
>
> Maybe I should explain it better. If I understand the global
> vision of the book right. By natural selection and thanks
> to some copy misstakes of the genes (evolution:-) the one's
> best equiped stay and the one's who don't go.
> But, at some point in the history of this evolution some
> genes split....and could only "build" a new copy when
> they came back together again (ok a bit alterd).
> If I see this right there was a point that "they" both were not
> able to evolve alone and had (to evolve all sort of things) to get
> back together again. In this period "they" could have been
> wiped out.............what am I missing here.........
> IMHO it was very tricky to give away the oppertunity to
> spread alone!? Of course I accept the "luck" or "random"
> factor in this story. But maybe some of you would like
> to share their "why" opinions.
>
> Greetings,
>
> Berrie

I would suggest that primitive sex evolved similarly to the way it is
still done in bacteria. Yes bacteria usually are asexual but on rare
occasion they exchange genetic information in a process called conjugation
in which "plus" (+) and minus (-) or positve and negative strands. The F+
or male has a plasmid that codes for a projectile (called a "sex pilus",
really it is) that then penetrates the F- or female bacteria and initiates
conjugation with an endonuclease that nicks one strand of the double helix
of the F-. The F- strand then adds this F+ strand DNA to her genome as
she synthesizes a complementary strand. No courting. No romance :-( oh
well. It's called Rolling Circle Replication in the Biochemistry book I
learned it from (Moran et al., 1994, ISBN 0-13-814443-5). I think that
our eukaryotic cellular structure is mostly or entirely explainable as
symbiotic prokaryotic-types of cells working together. Meiosis and
"crossing over" is an eloborate "rolling circle replication" in my
viewpoint. This approach to chemical, prebiotic, protobiotic evolution is
known as the endosymbiant hypothesis.

> Berrie Staring Email : staring@worldonline.nl
> Co-founder: Transcedo Dutch >H
> Site: www.dse.nl/~transed/
> " So you own the seed. It will not become
> a Bonsai, unless you let it grow and cut wise"
> =====================================

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Berrie Staring wrote:

Thanks for using NetForward!
http://www.netforward.com
v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v

(sorry for the horrible spelling)

Anders wrote:
>
> I'm not sure, but I don't see any big benefit from the selfish genes
> perspective with hermaphrodites; the child is still a mixture of the
> parent genomes. But I think I'm missing something obvious here...
>

Maybe I should explain it better. If I understand the global
vision of the book right. By natural selection and thanks
to some copy misstakes of the genes (evolution:-) the one's
best equiped stay and the one's who don't go.
But, at some point in the history of this evolution some
genes split....and could only "build" a new copy when
they came back together again (ok a bit alterd).
If I see this right there was a point that "they" both were not
able to evolve alone and had (to evolve all sort of things) to get
back together again. In this period "they" could have been
wiped out.............what am I missing here.........
IMHO it was very tricky to give away the oppertunity to
spread alone!? Of course I accept the "luck" or "random"
factor in this story. But maybe some of you would like
to share their "why" opinions.

Greetings,

Berrie

I would suggest that primitive sex evolved similarly to the way it is still done in bacteria.  Yes bacteria usually are asexual but on rare occasion they exchange genetic information in a process called conjugation in which "plus" (+) and minus (-) or positve and negative strands.  The F+ or male has a plasmid that codes for a projectile (called a "sex pilus", really it is) that then penetrates the F- or female bacteria and initiates conjugation with an endonuclease that nicks one strand of the double helix of the F-.  The F- strand then adds this F+ strand DNA to her genome as she synthesizes a complementary strand. No courting. No romance :-(  oh well.  It's called  Rolling Circle Replication in the Biochemistry book I learned it from (Moran et al., 1994, ISBN 0-13-814443-5).  I think that our eukaryotic cellular structure is mostly or entirely explainable as symbiotic prokaryotic-types of cells working together.  Meiosis and "crossing over" is an eloborate "rolling circle replication" in my viewpoint.  This approach to chemical, prebiotic, protobiotic evolution is known as the endosymbiant hypothesis.
Berrie Staring  Email : staring@worldonline.nl
Co-founder: Transcedo  Dutch >H
Site: www.dse.nl/~transed/
" So you own the seed. It will not become
  a Bonsai, unless you let it grow and cut wise"
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