# A slant on evolution



## Ukko (Jun 4, 2010)

Here is a link to a 'philosophical' article:

http://www.evolutionary-philosophy.net/sex.html

Quoted below is the Significant Paragraph:

<< One of the more outrageous alternative theories is the idea that males are essentially parasites. Sexual reproduction began when some parasitic organism began injecting its genetic material into an unwitting host in order to utilize its reproductive machinery like a virus. Over the course of evolutionary history, the parasites developed a co-evolutionary symbiosis with their hosts because of the shared genetic material and the benefits of sexual reproduction. Males may look similar to their reproductive hosts, but they are still essentially parasites. >>

This theory may feel _indisputably right_ to some of our members, so I felt it to be my duty as a Responsible Male to expand its propagation.

:tiphat:


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## Klavierspieler (Jul 16, 2011)

I feel a lock coming on...


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## Couchie (Dec 9, 2010)

It's possible. And where it didn't evolve to become symbiotic could be found in the romance of traumatic insemination.


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## Ukko (Jun 4, 2010)

Klavierspieler said:


> I feel a lock coming on...


Just in case, here is an addendum, offered by a friend:

Another thought. If the above is actually true, then the genetics for asexual reproduction may still be present, but inactive, in females. That could offer a bonanza to some future radical feminist geneticist seeking a way to divorce the entire male sex.

[It seems 'advisable' to note here that I am only a few days away from posting a _significant commentary_ on M-A Hamelin's recordings of Alkan's music. TC is not just Fun &Games, y'know.]


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## Couchie (Dec 9, 2010)

Crap........


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## kv466 (May 18, 2011)

Oh, geez...


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## Couchie (Dec 9, 2010)

My type breed by self-cannibalization. I consume a piece of my jelly. It is fertilized in the digestive tract, and gestates in only a few hours. The birth then, as you can imagine, is quite messy.


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## doctorGwiz (Sep 25, 2011)

An interesting philosophical view. Fossil evidence shows us that sexual reproduction in its most primitive forms has been around for at least a billion years. Benefits of sexual reproduction include an increase in genetic variation in an otherwise more or less homogenous population. Increased variation, while in some cases perpetuating deleterious genotypes, can confer an evolutionary advantage by increasing the probability of producing viable offspring. While it is true that males lack the machinery to produce new offspring and thus "hijack" the reproductive abilities of females, males contribute to the survivability of a species by increasing genetic variation through sexual reproduction. The existence of male and female, of two organisms contributing to the genetic information of their offspring, ultimately aids in the perpetuation of a species. And not all males "use" females to produce their offspring. When seahorses mate, females deposit their eggs in the male's "brood pouch," wherein the eggs become fully developed seahorses. In this situation males cannot produce the egg, but are however more responsible for the development of the fertilized egg. 

I do admit though that in human societies, genetic variation (at least how I understand it) is not necessarily critical to survival, as the selective pressures imposed upon humans are not as great (with the exception of epidemics) as those experienced by other organisms. Sexual reproduction may become irrelevant, but I would imagine not in the near future.


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## Fsharpmajor (Dec 14, 2008)

Hilltroll72 said:


> This theory may feel _indisputably right_ to some of our members, so I felt it to be my duty as a Responsible Male to expand its propagation.
> 
> :tiphat:


I shall try to be fair to both sexes. In bees, the males (drones) are pretty much useless for anything but passing on genes. In most catfish species, though, the ladies lead an idle, promiscuous life. The males guard the eggs, and once the eggs have hatched, guard the fry until they are big enough to fend for themselves. Females play no part in parenthood.

There's something else I need to find--an extreme example--but I'll need to do some googling.


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## Fsharpmajor (Dec 14, 2008)

Fsharpmajor said:


> There's something else I need to find--an extreme example--but I'll need to do some googling.


Here we are:

*http://en.wikipedia.org/wiki/File:Haplophryne_mollis_(female,_with_atrophied_male_attached).gif*


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## Ukko (Jun 4, 2010)

Ah yes. Note the swell in back of the male's forehead; he probably does all of the constructive thinking, eh?


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## regressivetransphobe (May 16, 2011)

Oh man. The extreme feminists are gonna love this.


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## Fsharpmajor (Dec 14, 2008)

regressivetransphobe said:


> Oh man. The extreme feminists are gonna love this.


Alas for the entire reputation of the masculine sex, it is true. The male regresses into nothing much more than a pair of gonads and a pair of eyes. I wonder if it even bothers to maintain its Y chromosome.


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## Philip (Mar 22, 2011)

sounds like a plausible theory, apart from the fact that the website seems to have no listed sources or authors..


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## Guest (Sep 28, 2011)

Not sure if anyone here is serious, but here goes...

Sexual reproduction is extremely important for evolution. Without sexual reproduction, lots of good ideas get lost. Every bloodline must get everything right. To create a silly example, even if one branch of the family tree develops an eye, it still may be toast if another branch is more resistant to cold weather. The survivors then have to stumble upon an eye all over again. Although if you look carefully you will see various techniques for sharing genetic material between asexual reproducers (eg viruses!), these are really the exception rather than the rule.

Sexual reproduction not only enables sharing genetic material, it requires it for reproduction. The result is that genes effectively evolve independently of (maternal) bloodlines. Moreover, genes can be mixed and matched, allowing for natural selection of combinations of genes. 

As a result, sexual reproduction turbocharges the whole process of evolution. How do I know? One of the hardest tasks in the history of life was to go from single-celled to multi-cellular cooperation and reproduction. With very limited exceptions, the only organisms which made this transition were sexual reproducers.

PS - Not sure if Couchie is single-celled or multi-cellular!


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## Ukko (Jun 4, 2010)

Just to toss a knuckleball at the wall here... placental mammals (which includes _most_ of the people I know) have what could be considered an odd arrangement: the genes which control the development of the placenta are provided in the sperm - never in the egg.


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## Fsharpmajor (Dec 14, 2008)

BPS said:


> Not sure if anyone here is serious, but here goes...
> 
> Sexual reproduction is extremely important for evolution. Without sexual reproduction, lots of good ideas get lost. Every bloodline must get everything right. To create a silly example, even if one branch of the family tree develops an eye, it still may be toast if another branch is more resistant to cold weather. The survivors then have to stumble upon an eye all over again. Although if you look carefully you will see various techniques for sharing genetic material between asexual reproducers (eg viruses!), these are really the exception rather than the rule.
> 
> ...


Here's an illustration of that. The banana is threatened with extinction, because it has lost its ability to sexually reproduce.

*http://www.telegraph.co.uk/news/wor...eless-banana-will-be-extinct-in-10-years.html*


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## regressivetransphobe (May 16, 2011)

Some day some of you will tell your grandchildren about what bananas tasted like, and they'll pause their virtual reality killing simulators and be like "sure, whatever".


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## Ukko (Jun 4, 2010)

Fsharpmajor said:


> Here's an illustration of that. The banana is threatened with extinction, because it has lost its ability to sexually reproduce.
> 
> *http://www.telegraph.co.uk/news/wor...eless-banana-will-be-extinct-in-10-years.html*


The genetic engineers the article mentions will probably get useful new bananas, both plantain and sweet. Who knows how soon the *evil genetic manipulation* fear will subside?


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## Fsharpmajor (Dec 14, 2008)

BPS said:


> Not sure if Couchie is single-celled or multi-cellular!


Single-celled. Couchie is a _Euglena_.

*http://www.infovisual.info/02/001_en.html*

That's the reason for the green colour.


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## clavichorder (May 2, 2011)

Fsharpmajor said:


> Single-celled. Couchie is a _Euglena_.
> 
> *http://www.infovisual.info/02/001_en.html*
> 
> That's the reason for the green colour.


Euglenas! Ah that takes me back to my childhood, that whip-like cilia on that big protozoan.


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## Ukko (Jun 4, 2010)

clavichorder said:


> Euglenas! Ah that takes me back to my childhood, that whip-like cilia on that big protozoan.


Your childhood? What?


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## science (Oct 14, 2010)

It's a famous theory, but I think it plays a little too fast and loose with the idea of parasitism.

A very plausible theory is that sexual reproduction evolved as a defense against parasites. A few biologists even regard it as having been proven. I don't have the expertise to judge, but I am personally unaware of a more compelling theory.


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## Lukecash12 (Sep 21, 2009)

Hilltroll72 said:


> Here is a link to a 'philosophical' article:
> 
> http://www.evolutionary-philosophy.net/sex.html
> 
> ...


The female does happen to have the host cells for male zygotes. So, we could be said to be parasites to this day.


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## Fsharpmajor (Dec 14, 2008)

Lukecash12 said:


> The female does happen to have the host cells for male zygotes. So, we could be said to be parasites to this day.


Both your terminology and your understanding of sexual reproduction are wrong. To put it simply, the male sex cell (sperm cell) and female sex cell (egg, or ovum) are _haploid_--they each have half the number of chromosomes of the rest of your body cells. They're called gametes. In humans, they each have 22 chromosomes, plus (in the case of a sperm cell) an X or Y chromosome, and (in the case of an egg cell) an X chromosome. The process of fertilization creates a _diploid_ zygote with 46 chromosomes--XX for a female zygote, XY for a male one.

Since the male sperm cell determines the sex of a child, males are needed for sexual reproduction, and males are unlikely to go extinct in the near future for that reason.


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## Lukecash12 (Sep 21, 2009)

Fsharpmajor said:


> Both your terminology and your understanding of sexual reproduction are wrong. To put it simply, the male sex cell (sperm cell) and female sex cell (egg, or ovum) are _haploid_--they each have half the number of chromosomes of the rest of your body cells. They're called gametes. In humans, they each have 22 chromosomes, plus (in the case of a sperm cell) an X or Y chromosome, and (in the case of an egg cell) an X chromosome. The process of fertilization creates a _diploid_ zygote with 46 chromosomes--XX for a female zygote, XY for a male one.
> 
> Since the male sperm cell determines the sex of a child, males are needed for sexual reproduction, and males are unlikely to go extinct in the near future for that reason.


Right. I was referring to the diploid zygote, as if it was a life form with a parasite in it. Just joshing you guys. I should at least be able to remember the whole xx xy deal, because my biology teacher from my sophomore year in high school, felt the need to repeat it far beyond when even the slowest students got it.


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## dmg (Sep 13, 2009)

science said:


> It's a famous theory, but I think it plays a little too fast and loose with the idea of parasitism.
> 
> A very plausible theory is that sexual reproduction evolved as a defense against parasites. A few biologists even regard it as having been proven. I don't have the expertise to judge, but I am personally unaware of a more compelling theory.


There was a recent article on this:

http://www.sciencedaily.com/releases/2011/07/110707141158.htm


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## dmg (Sep 13, 2009)

Lukecash12 said:


> Right. I was referring to the diploid zygote, as if it was a life form with a parasite in it. Just joshing you guys. I should at least be able to remember the whole xx xy deal, because my biology teacher from my sophomore year in high school, felt the need to repeat it far beyond when even the slowest students got it.


Interestingly, XX - XY is only found in mammals. There's even one mammal found (I believe it is a species of mole rat) without a Y chromosome altogether - the genes on the Y migrated to a non-sex chromosome. In many organisms, such as crocodilians, sex is determined by the temperature at which the embryos develop (the temperature of the nest) and therefore both sexes have the same set of chromosomes. In others (birds are an example), they have ZZ and ZW, where ZZ is male, and ZW is female - essentially a reverse setup from mammals.


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## Lukecash12 (Sep 21, 2009)

dmg said:


> Interestingly, XX - XY is only found in mammals. There's even one mammal found (I believe it is a species of mole rat) without a Y chromosome altogether - the genes on the Y migrated to a non-sex chromosome. In many organisms, such as crocodilians, sex is determined by the temperature at which the embryos develop (the temperature of the nest) and therefore both sexes have the same set of chromosomes. In others (birds are an example), they have ZZ and ZW, where ZZ is male, and ZW is female - essentially a reverse setup from mammals.


And I'm assuming that while there is still a distinct hormonal difference, in the case of xx xx and zz zw, that the difference is less perceptible?


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## dmg (Sep 13, 2009)

Nope - the difference isn't any more or less perceptible. The same genes are being triggered. The ancestral migration of the genes just resulted in different placement in the chromosomes. 

Note that in warm blooded animals, you cannot have a temperature-dependent gender trigger, as the temperatures will be the same throughout. There needed to be another gender trigger in endothermic organisms - and placement of gender-determining genes on different chromosomes fits the requirement.


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## EddieRUKiddingVarese (Jan 8, 2013)

wow that was scary


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