Re: Why Sexual reproduction is more popular

"Tim Tyler" <seemysig@xxxxxxxxxxxxxx> wrote in message news:h2r72u$5lr$1@xxxxxxxxxxxxxxxxxxxxxx
Perplexed in Peoria wrote:
"Tim Tyler" <seemysig@xxxxxxxxxxxxxx> wrote:

http://alife.co.uk/essays/gender_division/

Nice essay, Tim.

Thanks. It needs rewriting - but it makes a basic point and has some
references.

But there are two features of animal hermaphroditism
that you ought to mention and include in the essay.
1. Some hermaphroditic animals require reciprocal coitus. But plants
don't/can't use this strategy. Instead, they broadcast the male pollen.
Why don't plants engage in coitus? My guess is because they don't
have a fixed shape. (Well, also because they are immobile).

This is true. However, how this relates to separated genders is not
immediately obvious to me. It could be implicated - but you haven't
proposed how.

In the absense of reciprocal coitus protocols, non-sequential hermaphroditism
is unstable because desirable mates in terms of female choice may not
match the desirable mates for male-choice. You, yourself, may find that
you are scored as a desirable male partner, but an undesirable female one.
Hence you may have the incentive to focus your resources on one role
over the other.

But with reciprocal coitus protocols in place, if cheating can be prevented,
there is no instability. A standard argument shows that resources should
be equally divided between the sex roles.

2. Other hermaphroditic animals are serial hermaphrodites. But I don't
think that any (presumably perennial) plants are. Note that a serial
hermaphrodite is automatically sexually dimorphic and subject to
both male-combat and female-choice forms of sexual selection. My
own speculation is that serial hermaphroditism is the evolutionary
precursor of dioecious sexuality.

That is interesting and relevant. It weakens the argument for
the "different roles" theory a bit. However, it doesn't weaken it
terribly much. Control over development from birth provides more
in the way of options for specialisation than is present with
sequential hermaphrodism - which I understand is called "dichogamy".

See: http://en.wikipedia.org/wiki/Dichogamy

....for the story with plants.

Thx for the link. My ignorance of botany is again revealed. I had been
thinking in terms of plants expressing female one year and male the next.
I hadn't even considered that the two sexes might be expressed sequentially
in the same flower.

.

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