Is Gender Inevitable
Representative Trantis
[moderator's note: <snit> No. They have two SEXES. SEXES. NOT GENDERS.
Use the bluidy language properly. </snit>. - JAH]
This indicates that it evolved
early. Given that you are always going to get exploitation of a wide open
field, and that it makes no sense for both parents to make a nutritional
contriution to an ovum, given that the contribution of one is clerarly
sufficient, is it the case that the divisions into gender is as close as you
can get, evolutionary speaking, to something inevitable?
TWINBLUE
>Use the bluidy language properly. </snit>. - JAH]
Ah, While I might tend to agree with you here I think that you are going a bit
far.
For example consider the frequent discussion of single celled creatures who
engage in "sex" (exchange of genitic material) but who posess no gender and are
thus of neither sex. I believe they would be best described as "genderless"
rather than "unisexual" or "sexless".
TWINBLUE
TWINBLUE
evolutionary speaking, to something inevitable?>
While there may be other solutions to the
problem of genitic diversity and evolution
I would expect that where ever you find life
you will find sex. Since more than two varities of sex would be a bit unhandy
evolutionwise you would likely find most
creatures in the universe that are large enough to see with the naked eye are
divided into "male" and "female".
TWINBLUE
Anthony Cerrato
"TWINBLUE" <twin...@aol.com> wrote in message
news:bneq6e$17cc$1...@darwin.ediacara.org...
> >is it the case that the divisions into gender is as close
as you>can get,
> evolutionary speaking, to something inevitable?>
>
> problem of genitic diversity and evolution
> I would expect that where ever you find life
> you will find sex. Since more than two varities of sex
would be a bit unhandy
> evolutionwise you would likely find most
> creatures in the universe that are large enough to see
with the naked eye are
> divided into "male" and "female".
>
> TWINBLUE
I agree that more than two varieties of sex are a bit
unwieldy, but a single sex, viz., parthenogenesis (see also,
heterogamy, and metagenesis.) is certainly as efficient. For
all we know, budding might be the mainstay of the galaxy,
with our two sexes being the exception rather than the rule.
The key to single sex reproduction however, is to somehow
avoid the danger that lack of genetic diversity pure cloning
represents. ...tonyC
Malcolm
gender, but is not of female sex.
However feminists started using "gender" to refer to social aspects of sex
(women wear skirts, etc) as opposed to biological aspects, and then later
"gender" was used on job applications and similar places as a euphemism for
"sex", because "sex" is also shorthand for "sexual intercourse".
As I biologist I like crossing out "gender" and replacing with "sex".
As for two sexes being inevitable, in fungi there are complex mating
systems. In bacteria sex and reproduction are not linked. In plants and
molluscs some species are hermaphodite, though you still have two types of
gametes (sperm and ova).
Why are two sexes so common? I think the OP was probably right (and is
probably remembering something he read by Richard Dawkins). Once you have a
small difference in investment strategies escalate to the two extremes, so
eggs are the largest cells whilst sperm are the smallest in mammals.
Anon.
most sexual organisms have multiple mating types (there - my solution to
the sex/gender semantic debate! Do as mycologists do!), and then you
can go on to ask about the specialisation of mating types into
differentiable sexes.
Bob
--
Bob O'Hara
Rolf Nevanlinna Institute
P.O. Box 4 (Yliopistonkatu 5)
FIN-00014 University of Helsinki
Finland
Telephone: +358-9-191 23743
Mobile: +358 50 599 0540
Fax: +358-9-191 22 779
WWW: http://www.RNI.Helsinki.FI/~boh/
karate kid
early, b) it evolved many times. So it may have been with sex.
Greets,
the Kid
Tim Tyler
> The majority of creatures have two genders.
[...]
> This indicates that it evolved early. Given that you are always going
> to get exploitation of a wide open field, and that it makes no sense
> for both parents to make a nutritional contriution to an ovum, given
> that the contribution of one is clerarly sufficient, is it the case
> that the divisions into gender is as close as you can get, evolutionary
> speaking, to something inevitable?
Dimorphism based on gamete size is always likely to be widespread.
However, divided sexes are probably not so inevitable.
Today's divided sexes are enforced by mitochondrial inheritance
being through one parent only.
Remove the mitochondria and the remaining mechanisms for enforcing
division of the sexes are things such as it making sense for the seed
distributor to have its own body plan - rather than merely its own
specialised body parts.
If you are mobile, this still represents some pressure towards dividing
the sexes - but if you are something like a plant then devoting your
entire body plan to being male doesn't normally buy you very much.
There's a discussion of the future of gender in "Mendel's Demon" -
though I hasten to add that don't entirely agree with it. It
basically reaches the conclusion that our distant descendants will
be hermaphrodites; and that divided sexes are a temporary screw-up.
--
__________
|im |yler http://timtyler.org/ t...@tt1lock.org Remove lock to reply.
Anthony Cerrato
"Anon." <bob....@SPAMMERS.SOD.OFF.helsinki.fi> wrote in
message news:bnjht2$2dd3$1...@darwin.ediacara.org...
> TWINBLUE wrote:
> >>is it the case that the divisions into gender is as
close as you>can get,
> >
> > evolutionary speaking, to something inevitable?>
> >
> > problem of genitic diversity and evolution
> > I would expect that where ever you find life
> > you will find sex. Since more than two varities of sex
would be a bit unhandy
> > evolutionwise you would likely find most
> > creatures in the universe that are large enough to see
with the naked eye are
> > divided into "male" and "female".
> >
> What's wrong with a single sex? I think you have to start
by asking why
> most sexual organisms have multiple mating types (there -
my solution to
> the sex/gender semantic debate! Do as mycologists do!),
and then you
> can go on to ask about the specialisation of mating types
into
> differentiable sexes.
>
> Bob
I'm not sure what your point is exactly--but then I'm not
much of a mycologist. :) As a former chemist I'm not even
sure what you mean by "multiple mating types"--isn't that
just an analog of "sexes?" Do you mean multiple "modes" of
having sex or multiple ways (techniques?) of transferring
genetic material?
One thing which is obvious in my non-expert observation of
sexual vs nonsexual creatures: only sexual creatures fall
into the class of what I'd call "complex" life (and what are
generally the most commonly used definitions of same.) I
wonder what the general opinion is that sexuality is a
prerequisite for bio-complexity (and possibly, resultant
intelligence,) or if it plays little or no role in evolution
of complex life. BTW, I'm excluding for the moment,
aggregates of biological units in considering complexity
(e.g., hives/nests, slime molds, etc.) although such are
certainly pertinent with regard to semantics in the
definitions of bio-compleity. ...tonyC
Tim Tyler
> "TWINBLUE" <twin...@aol.com> wrote in message
>> >[moderator's note: <snit> No. They have two SEXES. SEXES.
>> > NOT GENDERS. Use the bluidy language properly. </snit>. - JAH]
>>
>> Ah, While I might tend to agree with you here I think that you are going >
>> a bit far.
>> For example consider the frequent discussion of single celled creatures >
>> who engage in "sex" (exchange of genitic material) but who posess no
>> gender and are thus of neither sex. I believe they would be best
>> described as "genderless" rather than "unisexual" or "sexless".
>>
> "Gender" is properly a grammatical term. In French a "table" has feminine
> gender, but is not of female sex.
> However feminists started using "gender" to refer to social aspects of sex
> (women wear skirts, etc) as opposed to biological aspects, and then later
> "gender" was used on job applications and similar places as a euphemism for
> "sex", because "sex" is also shorthand for "sexual intercourse".
> As I biologist I like crossing out "gender" and replacing with "sex".
``I make no apology for using the word gender when I mean sex (male or
female); I know it is a word that originally referred only to
grammatical categories, but meanings change and it is usefully
unambiguous to have a word other than sex for males and females.''
- Matt Ridley, TRQ, p.345.
[moderator's paraphrase: "People are sloppy; I make no apology for
abusing the language since it's already used to it." - JAH]
Anon.
have offspring. Humans have two such sexes (and the other differences
are secondary). Some fungi also have two sexes, or mating types (e.g.
the cereal mildews). Others have many more, some into the thousands.
> One thing which is obvious in my non-expert observation of
> sexual vs nonsexual creatures: only sexual creatures fall
> into the class of what I'd call "complex" life (and what are
> generally the most commonly used definitions of same.)
All definitions written by sexual humans. :-)
I
> wonder what the general opinion is that sexuality is a
> prerequisite for bio-complexity (and possibly, resultant
> intelligence,) or if it plays little or no role in evolution
> of complex life. BTW, I'm excluding for the moment,
> aggregates of biological units in considering complexity
> (e.g., hives/nests, slime molds, etc.) although such are
> certainly pertinent with regard to semantics in the
> definitions of bio-compleity. ...tonyC
>
I don't know if there's a definite answer to that yet. We're still
struggling to find out why sex occured in the first place.
Bob
Tim Tyler
> "Anon." <bob....@SPAMMERS.SOD.OFF.helsinki.fi> wrote in
>> What's wrong with a single sex? I think you have to start
>> by asking why most sexual organisms have multiple mating
>> types (there - my solution to the sex/gender semantic debate!
>> Do as mycologists do!), and then you can go on to ask about
>> the specialisation of mating types into differentiable sexes.
>
> I'm not sure what your point is exactly--but then I'm not
> much of a mycologist. :) As a former chemist I'm not even
> sure what you mean by "multiple mating types"--isn't that
> just an analog of "sexes?" Do you mean multiple "modes" of
> having sex or multiple ways (techniques?) of transferring
> genetic material?
``Mushrooms have as many as 36,000 sexes, and a strange growth
called slime mould has about thirteen.''
- http://news.bbc.co.uk/1/low/sci/tech/specials/sheffield_99/447058.stm
Tim Tyler
> We're still struggling to find out why sex occured in the first place.
It least these days the problem is not that we don't have explanations -
it is that we have too many explanations - and are not sure how to divide
the credit (or blame) between them.
William Morse
@darwin.ediacara.org:
> One thing which is obvious in my non-expert observation of
> sexual vs nonsexual creatures: only sexual creatures fall
> into the class of what I'd call "complex" life (and what are
> generally the most commonly used definitions of same.) I
> wonder what the general opinion is that sexuality is a
> prerequisite for bio-complexity (and possibly, resultant
> intelligence,) or if it plays little or no role in evolution
> of complex life. BTW, I'm excluding for the moment,
> aggregates of biological units in considering complexity
> (e.g., hives/nests, slime molds, etc.) although such are
> certainly pertinent with regard to semantics in the
> definitions of bio-compleity. ...tonyC
If memory serves me both dandelions and rotifers reproduce exclusively
asexually. Other animals and plants can do so under some conditions. Again
going on memory, dandelions are thought to be a temporary exception to the
general rule of sexual reproduction for "complex" life (i.e. they only
recently adopted asexual reproduction and may revert in the future) and
nobody has a good explanation for rotifers.
Yours,
Bill Morse
TomHendricks474
It least these days the problem is not that we don't have explanations -
it is that we have too many explanations - and are not sure how to divide
the credit (or blame) between them.
--
__________
|im |yler http://timtyler.org/ t...@tt1lock.org Remove lock to reply.
>>
If my idea of life being energy moderation with modification through descent,
is correct; then there are two sexes because in temperature you can only get
hotter or colder (no third option)
TH
Tim Tyler
> If memory serves me both dandelions and rotifers reproduce exclusively
> asexually.
Not exclusively:
``The common dandelion (Taraxacum) comprises both sexual and asexual
(apomictic) plants [...]''
- http://www.niwi.knaw.nl/nl/oi/nod/onderzoek/OND1273759/toon
Name And Address Supplied
> >>is it the case that the divisions into gender is as close as you>can get,
> >
> > evolutionary speaking, to something inevitable?>
> >
> > While there may be other solutions to the
> > problem of genitic diversity and evolution
> > I would expect that where ever you find life
> > you will find sex. Since more than two varities of sex would be a bit unhandy
> > evolutionwise you would likely find most
> > creatures in the universe that are large enough to see with the naked eye are
> > divided into "male" and "female".
> >
> What's wrong with a single sex? I think you have to start by asking why
> most sexual organisms have multiple mating types (there - my solution to
> the sex/gender semantic debate! Do as mycologists do!), and then you
> can go on to ask about the specialisation of mating types into
> differentiable sexes.
>
Mating types and sexes aren't quite the same. The former are possibly
helpful for preventing inbreeding where this might be harmful. It
doesn't seem to represent divergence in strategy in any sense, whereas
males and females are (with a few exceptions) associated with a host
of stereotypical adaptations which appear to be geared towards
definite, divergent strategies.
In some species there are dimorphisms within, say, males, relating to
reproductive strategies. Perhaps these should be regarded as similar
to separation of sexes. For example, the well known RPS game played
by orange, blue and red morphs of male lizards. Perhaps in that
species we should recognise that there are 4 sexes (three different
male types and a female), or perhaps 2 sexes but with one including 3
subsexes?
Or maybe not . . .
Anthony Cerrato
"William Morse" <wdm...@twcny.rr.com> wrote in message
news:bnsd04$1srl$1...@darwin.ediacara.org...
> Anthony Cerrato <tcer...@optonline.net> wrote in
news:bnn5fr$eit$1
> @darwin.ediacara.org:
>
> > One thing which is obvious in my non-expert observation
of
> > sexual vs nonsexual creatures: only sexual creatures
fall
> > into the class of what I'd call "complex" life (and what
are
> > generally the most commonly used definitions of same.) I
> > wonder what the general opinion is that sexuality is a
> > prerequisite for bio-complexity (and possibly, resultant
> > intelligence,) or if it plays little or no role in
evolution
> > of complex life. BTW, I'm excluding for the moment,
> > aggregates of biological units in considering complexity
> > (e.g., hives/nests, slime molds, etc.) although such are
> > certainly pertinent with regard to semantics in the
> > definitions of bio-compleity. ...tonyC
>
exclusively
conditions. Again
> going on memory, dandelions are thought to be a temporary
exception to the
> general rule of sexual reproduction for "complex" life
(i.e. they only
> recently adopted asexual reproduction and may revert in
the future) and
> nobody has a good explanation for rotifers.
>
> Yours,
>
> Bill Morse
Hi Bill. I'm sorry that I didn't explain what I really meant
more clearly. I put "complex" life in quotes initially since
I didn't mean it in the usual biological technical sense (I
guess--I'm a chemist not biologist :).) What I meant was
complex in the very subjective sense of larger animals for
example; e.g., increased complexity being from
bacteria/prokaryotes, to your dandelions and rotifers, to
fish, reptiles/small mammals, to horses, monkeys, and
finally, man.
While evolution isn't necessarily directed, there has been a
persistent increase in complexity with time in my,
admitedly, loose view of complexity (unfortunately, I am not
familiar enough with more precise current non-traditional
definitions of this kind of complexity tho.) Do you agree
that in my above "list" that the higher degree of some loose
form of complexity demands (bi)sexuality, or, would it ever
be possible to reach animals as complex as horses, monkeys
and humans through evolution without sex?
....tonyC
r norman
name_and_add...@hotmail.com (Name And Address Supplied)
wrote:
What you are describing is a whole continuum of reproductve
strategies. Sexual dimorphism varies enormously, from strikingly
different male and female appearance and behavior to complete identify
between individual organisms (as in hermaphroditic animals and perfect
flowers) but formation of different gametes, to only chemical
differences in apparently identical gametes (mating types and
isogamy).
There does seem to be strong selective pressure to favor sexual
reproduction, meanng simply alternation of haploid and diploid states
and the possibility of genetic recombination. This does not require
any sort of sexual differentiation or dimorphism. The "mating type"
system is true sexual reproduction.
Given that two gametes must get together, if the gametes are not
already the usual motile form of the species, there does seem to be
strong selective pressure to favor one gamete taking on the task of
moving to the other, usually becoming small and motile, while the
other taking on the task of providing nutrients to help ensure the
survival of the zygote, usually becoming large and stationary. That
produces what we call two sexes, with male structures producing the
motile gamete (sperm) and female structures producing the nutritive
gamete (egg). There is still no need to invoke different body forms
or behaviors.
William Morse
@darwin.ediacara.org:
>
> "William Morse" <wdm...@twcny.rr.com> wrote in message
> news:bnsd04$1srl$1...@darwin.ediacara.org...
>> Anthony Cerrato <tcer...@optonline.net> wrote in
> news:bnn5fr$eit$1
>> @darwin.ediacara.org:
>>
>> > One thing which is obvious in my non-expert observation
> of
>> > sexual vs nonsexual creatures: only sexual creatures
> fall
>> > into the class of what I'd call "complex" life
>> If memory serves me both dandelions and rotifers reproduce
> exclusively
>> asexually.
> Hi Bill. I'm sorry that I didn't explain what I really meant
> more clearly. I put "complex" life in quotes initially since
> I didn't mean it in the usual biological technical sense (I
> guess--I'm a chemist not biologist :).) What I meant was
> complex in the very subjective sense of larger animals for
> example; e.g., increased complexity being from
> bacteria/prokaryotes, to your dandelions and rotifers, to
> fish, reptiles/small mammals, to horses, monkeys, and
> finally, man.
> While evolution isn't necessarily directed, there has been a
> persistent increase in complexity with time in my,
> admitedly, loose view of complexity (unfortunately, I am not
> familiar enough with more precise current non-traditional
> definitions of this kind of complexity tho.) Do you agree
> that in my above "list" that the higher degree of some loose
> form of complexity demands (bi)sexuality, or, would it ever
> be possible to reach animals as complex as horses, monkeys
> and humans through evolution without sex?
The subject of a persistent increase in complexity with time has a
somewhat tangled history in evolution. Gould wrote a book - "Full
House" - arguing that the increase in complexity was not a result of
direction, but simply the net result of a drunkard's walk away from zero
complexity. I agree with you and disagree with Gould on this point, and
in fact there was a recent reference in Science that seemed to verify an
overall increase in diversity since the Cretaceous. But that may be
different from your overall point, which is whether complexity can be
achieved without sex.
A similar question was in fact very recently discussed on this newsgroup.
I and others argued that whether evolution could proceed without sex, sex
would be an inevitable result of evolution. This point was very well
fleshed out by Wirt Atmar in a follow in early October on a thread about
"Levels of Selection". So even if you _could_ reach complex animals
without sex, you _wouldn't_ reach complex animals without also reaching
sex.
Yours,
Bill Morse
Reference previous discussion on gender by Wirt
Peter F
news:bnve1j$2sn6$1...@darwin.ediacara.org...
>
> Hi Bill. I'm sorry that I didn't explain what I really meant
> more clearly. I put "complex" life in quotes initially since
> I didn't mean it in the usual biological technical sense (I
> guess--I'm a chemist not biologist :).) What I meant was
> complex in the very subjective sense of larger animals for
> example; e.g., increased complexity being from
> bacteria/prokaryotes, to your dandelions and rotifers, to
> fish, reptiles/small mammals, to horses, monkeys, and
> finally, man.
>
> While evolution isn't necessarily directed, there has been a
> persistent increase in complexity with time in my,
> admitedly, loose view of complexity (unfortunately, I am not
> familiar enough with more precise current non-traditional
> definitions of this kind of complexity tho.) Do you agree
> that in my above "list" that the higher degree of some loose
> form of complexity demands (bi)sexuality, or, would it ever
> be possible to reach animals as complex as horses, monkeys
> and humans through evolution without sex?
> ....tonyC
>
A very deep and difficult-to-answer question!
(Am not surprised no one has dared to dive in to debate it, until now. ;->)
In spite of all that, my bet is that it could not have happened without sex.
Sex adds (is in itself) a 'higher gear/degree of biological complexity'. And
it seems that (apart from being confusing to parasites) it may act as a
lever or building-platform, upon which, (or that constitutes a relatively
fundamental opportunity, or launching pad, from which) a 'next evolutionary
stage' of correspondingly more complex organisms can emerge.
Yours never inEPT,
%-}
Peter F.
TomHendricks474
somewhat tangled history in evolution. Gould wrote a book - "Full
House" - arguing that the increase in complexity was not a result of
direction, but simply the net result of a drunkard's walk away from zero
complexity. I agree with you and disagree with Gould on this point, and
in fact there was a recent reference in Science that seemed to verify an
There is a fallacy in the analogy. What if the drunkard
sits down and doesn't move at all.
Inherent in Gould's version is continual movement. But that is not the case -
and someone advocating punctuated equilibrium, as he did, should have seen
that.
Tom Hendricks