Re: Why Sexual reproduction is more popular

On Jul 7, 7:08=A0pm, "Perplexed in Peoria" <jimmene...@xxxxxxxxxxxxx>
wrote:
"Tim Tyler" <seemy...@xxxxxxxxxxxxxx> wrote in messagenews:h2r72u$5lr$1@d=
arwin.ediacara.org...
Perplexed in Peoria wrote:
"Tim Tyler" <seemy...@xxxxxxxxxxxxxx> wrote:

But there are two features of animal hermaphroditism
that you ought to mention and include in the essay.
1. =A0Some hermaphroditic animals require reciprocal coitus. =A0But pl=
ants
don't/can't use this strategy. =A0Instead, they broadcast the male pol=
len.
Why don't plants engage in coitus? =A0My guess is because they don't
have a fixed shape. =A0(Well, also because they are immobile).

This is true. =A0However, how this relates to separated genders is not
immediately obvious to me. =A0It could be implicated - but you haven't
proposed how.

In the absense of reciprocal coitus protocols, non-sequential hermaphrodi=
tism
is unstable because desirable mates in terms of female choice may not
match the desirable mates for male-choice. =A0You, yourself, may find tha=
t
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 prevent=
ed,
there is no instability. =A0A standard argument shows that resources shou=
ld
be equally divided between the sex roles.

I had to look up what "reciprocal coitus" meant: in unilateral
mating, only one critter inseminates the other, while in
reciprocal mating, both critters inseminate each other.

I am still not sure I understand the argument. However, the
conclusion seems to involve some animals getting to use
reciprocal coitus sometimes - and those animals being less
likely to have divided genders.

It seems fair enough - but I don't know enough about it to say very
much. I don't know how common reciprocal coitus is. Also, I think
we are supposed to assume that females can usually decide when they
get fertilised - since they are in charge of their own plumbing.
Just because some sperm is delivered, that doesn't mean the females
have to use it. For example, they could do something like what
ducks do - turn their reproductive tract into a maze of twisty
passages for losing bad sperm in.

"Duck genitals locked in arms race"

- http://www.cosmosmagazine.com/node/1277
--
__________
|im |yler http://timtyler.org/ tim@xxxxxxxxxxx Remove lock to
reply.

.

Quantcast