Freethought & Rationalism Archive

Supercaliber · 07-27-2003, 06:11 PM

I always said I wouldn't produce my 1st thread until I had something to offer..but I don't, and I've been called out.. again, by my extremely fundy boss (that's why I'm here..so much absurdity has caused me to seek)..Since I am concerned of losing my job if I announced my atheism, I usually just ask him simple questions of the bible and try to have him answer all the absurd stories that he'd like me to believe..I told him I frequent this board regularly and for several months now he has "called me out" and to ask the "board of fools".." How the male and female sex organs could have evolved?"..

It's always his wildcard whenever we talk of evolution and I just can't begin to answer it for him..He throws every question possible at me.."How can a penis work 1/2 way? "When was it done evolving?" "What came 1st, the penis or the vagina?" "Did man just have sex on the 1st day after evolving, but not on the day before?"....It goes on and on..

There was a thread on the board a few weeks ago dealing with this and honestly, it was never answered properly..It WAS disapointing..

It just seems that the fundy viewpoint on this matter is hard to beat..Are they right on this one?..I'm very confused on this and could use some help..Thanks all.

Supercaliber

Doubting Didymus · 07-27-2003, 06:30 PM

The reason that thread never 'properly' answered this question is because we've done it before.

Some of us have even done it twice.

The short answer is that the sexes were around well and truly before sex organs developed. It feels like a blow to the male ego, but you don't need a cock to have sex. There are countless organisms that get it on without much in the way of equipment. Amphibians use cloacas (that's one all-purpose multifunction orifice for all your sexual AND waste management needs). Plants have both sexual parts on the same organ (Bisexual flowers. They can even have sex with themselves. Ever get the feeling that a flower is looking smugly at you?) Fungi not only don't need ANY organised sexual systems, (the fungal 'fruit' is for spore dispersal and not actually for having sex with, despite its obviously phallic appearance), but they don't even use two sexes, but have multiple breeding types with complicated sexual relationships. It's enough to make me feel like I've been sold short, being in a species with only two sexes and a higly limited number of sexual combinations to try.

In other words, you can start having sex before you have sex organs, and your organs can start out multifunctional before they diverge into brredingtype - specific organs. Thats the short answer. The long answer might involve a series of postulated possible intermediates linking asexual protozoans with sexed metazoans, coupled with a presentation of the evidence we have to date about the forms that actually existed. I'm going to a lecture now, and I might consider writing it up for you later. Unless some kind soul beats me to it.

Ta.
- DD.

GunnerJ · 07-27-2003, 06:30 PM

I don't have a specific answer, but you may wish to remind your boss that a theory isn't invalid simply because J. Random Layman who hasn't spent his whole life studying said theory can't answer every question on it. In other words, "I haven't done enough studying of the subject to answer that question. A professor of biology at (a nearby college) may be able to answer it though." If he actually cares about finding out about the subject, then this should satisfy him. If it doesn't, then he's just looking for a way to bully you. If he persists, simply tell him that you feel that discussing the subject further is an inappropriate distraction from your work, and that you'd prefer to keep your discussions with him on a professional level, or something like that. If he still persists, see if there are any rules about harassment of employees for religious reasons (i.e., he's singling you out for abuse and embarrassment, simply because fo your lack of belief.)

Happy Wonderer · 07-27-2003, 06:42 PM

Quote:

Plants have both sexual parts on the same organ (Bisexual flowers. They can even have sex with themselves. Ever get the feeling that a flower is looking smugly at you?)

DD, your entire response was classic! :notworthy: :notworthy:

caravelair · 07-27-2003, 07:08 PM

i will add that there is some more information about this on don lindsay's page.

Nic Tamzek · 07-27-2003, 07:22 PM

The sequence is something like this:

- unicellular organisms

- unicellular organisms with meiosis ("sex" develops here, but the two "gametes" are identical

- differentiation of gametes into (1) big fat egg with lots of resources and (2) small motile gamete that can travel (sperm) ("the sexes" begin to develop here)

- multicellular organisms with external fertilization (eggs and sperm released into the water, where they combine). This pattern is common in fish and (IIRC) many amphibians

- However, many times independently internal fertilization has developed (in fish, amphibians, and, obviously the ancestors of reptiles)

An example in one small group of fishes:

Quote:

http://www.uga.edu/srel/Reprint/1831.htm

The evolution of copulatory organs, internal fertilization, placentae and viviparity in killifishes (Cyprinodontiformes) inferred from a DNA phylogeny of the tyrosine kinase gene X-src

SUMMARY

Cyprinodontiforms are a diverse group of approximately 900 pantropical and temperate fishes, mostly found in freshwater. Whereas the vast majority of fishes lay eggs (i.e. are oviparous), this group is unusual in that four groups of cyprinodont fishes give birth to living young (i.e. are viviparous). A molecular phylogenetic hypothesis was based on partial DNA sequences of the tyrosine kinase gene X-src. The study included the major lineages of 'fishes of the suborder Cyprinodontoidei, order Cyprinodontiformes. Our phylogeny agrees with some but not all of the conclusions of a previous morphological cladistic analysis (Parenti (Bull. A . Mus. nat. Hist. 168, 335 (1981)). The diflerences are: (i) the Prof'undulidae are the sister group to the Goodeidae, not the sister group to all other cyprinodontolds; (11) Fundulidae are the sister group to the Profundulidae and Goodeidae; (iii) Cubanichthys and the Cyprinodontinae might not be sister taxa; (iv) Cubanichthys, and not the Profundulidae, might be the most basal member of the cyprinodontoids; and (v) the Anablepinae and Poeciliinae might be sister groups. The molecular phylogeny was used to reconstruct the evolution of major life-history traits such as internal fertilization, copulatory organs, livebearing and placentas. Internal fertilization, modifications of the male's anal fin to form a copulatory organ, and viviparity probably evolved independently three times in cyprinodontiform fishes: in the subfamilies Goodeinae, Anablepinae and Poeciliinae (sensu Parenti 198 1). The evolution of bundled sperm, spermatozeugmata, is probably not a prerequisite for internal fertilization because at least one species with internal fertilization has free spermatozoa. Livebearing (viviparity), which takes the form of ovoviviparity (where embryos are nourished by their yolk sac only), evolved only in the subfamily Poeciliinae. Advanced forms of'viviparity, in which the mother provides additional nourishment to the embryos through placenta-like structures, apparently evolved at least three times from egg-laying ancestors: in the subfamilies Goodeinae, Anablepinae, and more than once in the Poeciliinae.

And another:

Quote:

http://www.iubs.org/test/bioint/41/13.htm

One class of vertebrates--the Amphibia--is my focus because live-bearing modes of reproduction have evolved 8 times in frogs, 3 times in salamanders, and 2-4 times in caecilians (gymnophiones). I analyze the pattern and process of the evolution of viviparity in an explicitly phylogenetic context; patterns can be elucidated and ancestor-descendant character state changes deduced. A phylogenetic hypothesis also facilitates selection of appropriate taxa for study. I structure questions hierarchically so that questions relate to each other, and data are interactive. I search for levels of explanations of the associations of traits. Among many topics, I examine:

1. Internal fertilization is necessary but not sufficient for intraoviductal retention of fertilized eggs. Among frogs, internal fertilization occurs in the phylogenetically most basal frog, which uses remnants of its tadpole tail as an intromittent organ, and in some highly derived taxa via cloacal apposition. Basal salamanders have external fertilization; derived taxa have internal fertilization by the male depositing a spermatophore, which the female picks up with her cloaca as part of the courtship sequence. Most salamanders lay their fertilized eggs. All caecilians have internal fertilization; they avert the rear part of the cloaca as an intromittent organ. The mechanism of internal fertilization therefore differs dramatically among these groups, and I consider that evidence of homoplasy, with the evolution of multiple mechanisms to serve the same general phenomenon. I examine the way that these structures facilitate sperm transport, especially whether there are associated derived traits (there are). I also examine the structural and functional morphology of the intromittent organs.

2. Oviduct morphology is a major part of the investigation. Much is known of the physiology and endocrinology of the oviduct, including at cellular and molecular levels, for a few species of frogs and fewer of salamanders. However, all of them have basal, not derived, modes of reproduction. Therefore I examine the morphology and histochemistry of the oviducts of species with live-bearing modes of reproduction, and compare data obtained to those for oviparous taxa. I am interested in the way that modifications of the oviduct facilitate live-bearing.

In most viviparous oviductal retainers, embryonic development is dependent on the yolk reserve for nutrition, but both developing young and the maternal oviducts provide well vascularized surfaces for gaseous exchange. However, in two species of frogs, one of salamanders, and at least 30 of caecilians, the oviductal epithelium secretes a nutrient material that is ingested by the developing embryos. I am investigating the cell biology of the provision of the nutrient material, and the developmental biology of the embryos and their means of ingesting the nutrients, as well as maternal influences on them during the gestation period. I collaborate in examination of the evolution of cannibalism as a form of �maternal nutrition� in populations of a salamander. I also study the evolution of live-bearing that involve maintenance of the embryos outside of the oviducts, specifically in the skin of the back in certain frogs.

There are multiple instances of convergent evolution--homoplasy--at several different levels of the morphological and developmental hierarchies of organization of viviparous modes of reproduction. We use diverse techniques to examine the hierarchical interaction of the several components, and their interactions, all in a phylogenetic context to assess patterns of evolution.

There is -- ahem -- more than one way to do "it".

- Keep in mind that the ability to change sex is common in fish and persists into some amphibians and (IIRC) a few reptiles.

- lower tetrapods and even marsupials and basal placental mammals have, IIRC, only a cloaca. How, erm, one hole developed into two is an interesting question that I'd like to know more about. OK, not particularly, but if one wants to know, comparative research like the above is where to look.

Another resource:

Unicellular protists and the origins of sexual reproduction

Albion · 07-27-2003, 07:54 PM

Quote:

I told him I frequent this board regularly and for several months now he has "called me out" and to ask the "board of fools".." How the male and female sex organs could have evolved?"..

If he thinks a board full of scientists and university professors and other assorted scientifically literate people is a board of fools, there's nothing anybody here can say that will change his mind about evolution. If someone comes up with a watertight response to one of his challenges, he'll just bin it and go on to the next challenge without even stopping to notice that his first challenge was answered.

Sexual reproduction pre-dated the emergence of vertebrates by a long way. I don't see why he's got this idea that the immediate ancestor of humans was somehow asexual. Of course, we all know he doesn't think that humans had an immediate ancestor, but that's his problem.

Why not ask him to come here himself? I assume he isn't scared of a few fools.

Doubting Didymus · 07-27-2003, 08:41 PM

What do yer say, supercaliber? Need more? Clearer? Specifics?

lpetrich · 07-27-2003, 09:17 PM

Seems like the old "half an eye" conundrum. And with the same resolution:

"Half a penis" is a low-quality penis, but still better than nothing, just as "half an eye" is a low-quality eye, but still better than nothing.

Happy Wonderer · 07-27-2003, 10:04 PM

These are strawmen arguments of course, but it is kind of fun to think about 'soundbite' replys to them that don't misrepresent the actual science too much.

How can 1/2 of a penis work?
The "half an X" argument is silly, nobody argues that ancestor species were like legos with half the blocks missing. Organs evolve from very similar organs in other species, sometimes simply becoming (er...) larger in response to natural selection.

However, half a penis seems like it would work, assuming we are talking about removing the end and not dividing down the middle... More to the point, a penis half the size of the typical male human's would probably still work well enough for reproduction. The important part is the testicle, and guess what -- we have two of them. People with one testicle are quite able to reproduce. People with small testicles reproduce, as well.

When did it stop evolving?
It hasn't. (Just say "and mine is better than yours!")

Which came first, the penis or the vagina?
The vagina. Virtually everything important to reproduction is part of the human female's anatomy. With enough technology, the last female human could probably clonally reproduce. Ain't gonna happen if the last human is male. (This is a crude way of making a point said much more accurately by previous posters.)

Who did the first human have sex with?
I think that is what you mean. The first true human had sex with the most immediate human ancestor. Neither probably realized that there was anything different about the other -- the closest human ancestor probably looked about like your average creationist. Even if we had living representatives of the 10 most immediate ancestors, we would be hard pressed to draw the line between 'human' and 'non-human.' (Which makes choosing the '10 most immediate' pretty difficult, but anyway...)

Look at the debates today over whether certain genetically isolated salmon runs represent unique species and are thus qualified for endangered species protection.

hw

07-27-2003, 06:11 PM	#1
Supercaliber Junior Member Join Date: Apr 2003 Location: Ct Posts: 7	From where sex organs?.. I always said I wouldn't produce my 1st thread until I had something to offer..but I don't, and I've been called out.. again, by my extremely fundy boss (that's why I'm here..so much absurdity has caused me to seek)..Since I am concerned of losing my job if I announced my atheism, I usually just ask him simple questions of the bible and try to have him answer all the absurd stories that he'd like me to believe..I told him I frequent this board regularly and for several months now he has "called me out" and to ask the "board of fools".." How the male and female sex organs could have evolved?".. It's always his wildcard whenever we talk of evolution and I just can't begin to answer it for him..He throws every question possible at me.."How can a penis work 1/2 way? "When was it done evolving?" "What came 1st, the penis or the vagina?" "Did man just have sex on the 1st day after evolving, but not on the day before?"....It goes on and on.. There was a thread on the board a few weeks ago dealing with this and honestly, it was never answered properly..It WAS disapointing.. It just seems that the fundy viewpoint on this matter is hard to beat..Are they right on this one?..I'm very confused on this and could use some help..Thanks all. Supercaliber

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07-27-2003, 06:30 PM	#2
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	The reason that thread never 'properly' answered this question is because we've done it before. Some of us have even done it twice. The short answer is that the sexes were around well and truly before sex organs developed. It feels like a blow to the male ego, but you don't need a cock to have sex. There are countless organisms that get it on without much in the way of equipment. Amphibians use cloacas (that's one all-purpose multifunction orifice for all your sexual AND waste management needs). Plants have both sexual parts on the same organ (Bisexual flowers. They can even have sex with themselves. Ever get the feeling that a flower is looking smugly at you?) Fungi not only don't need ANY organised sexual systems, (the fungal 'fruit' is for spore dispersal and not actually for having sex with, despite its obviously phallic appearance), but they don't even use two sexes, but have multiple breeding types with complicated sexual relationships. It's enough to make me feel like I've been sold short, being in a species with only two sexes and a higly limited number of sexual combinations to try. In other words, you can start having sex before you have sex organs, and your organs can start out multifunctional before they diverge into brredingtype - specific organs. Thats the short answer. The long answer might involve a series of postulated possible intermediates linking asexual protozoans with sexed metazoans, coupled with a presentation of the evidence we have to date about the forms that actually existed. I'm going to a lecture now, and I might consider writing it up for you later. Unless some kind soul beats me to it. Ta. - DD.

07-27-2003, 06:30 PM	#3
GunnerJ Banned Join Date: Sep 2001 Location: a place where i can list whatever location i want Posts: 4,871	I don't have a specific answer, but you may wish to remind your boss that a theory isn't invalid simply because J. Random Layman who hasn't spent his whole life studying said theory can't answer every question on it. In other words, "I haven't done enough studying of the subject to answer that question. A professor of biology at (a nearby college) may be able to answer it though." If he actually cares about finding out about the subject, then this should satisfy him. If it doesn't, then he's just looking for a way to bully you. If he persists, simply tell him that you feel that discussing the subject further is an inappropriate distraction from your work, and that you'd prefer to keep your discussions with him on a professional level, or something like that. If he still persists, see if there are any rules about harassment of employees for religious reasons (i.e., he's singling you out for abuse and embarrassment, simply because fo your lack of belief.)

07-27-2003, 07:08 PM	#5
caravelair Regular Member Join Date: Apr 2003 Location: toronto Posts: 420	i will add that there is some more information about this on don lindsay's page.

07-27-2003, 08:41 PM	#8
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	What do yer say, supercaliber? Need more? Clearer? Specifics?

07-27-2003, 09:17 PM	#9
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	Seems like the old "half an eye" conundrum. And with the same resolution: "Half a penis" is a low-quality penis, but still better than nothing, just as "half an eye" is a low-quality eye, but still better than nothing.

07-27-2003, 10:04 PM	#10
Happy Wonderer Veteran Join Date: Jan 2002 Location: Washington, the least religious state Posts: 5,334	These are strawmen arguments of course, but it is kind of fun to think about 'soundbite' replys to them that don't misrepresent the actual science too much. *How can 1/2 of a penis work?* The "half an X" argument is silly, nobody argues that ancestor species were like legos with half the blocks missing. Organs evolve from very similar organs in other species, sometimes simply becoming (er...) larger in response to natural selection. However, half a penis seems like it would work, assuming we are talking about removing the end and not dividing down the middle... More to the point, a penis half the size of the typical male human's would probably still work well enough for reproduction. The important part is the testicle, and guess what -- we have two of them. People with one testicle are quite able to reproduce. People with small testicles reproduce, as well. When did it stop evolving? It hasn't. (Just say "and mine is better than yours!") Which came first, the penis or the vagina? The vagina. Virtually everything important to reproduction is part of the human female's anatomy. With enough technology, the last female human could probably clonally reproduce. Ain't gonna happen if the last human is male. (This is a crude way of making a point said much more accurately by previous posters.) Who did the first human have sex with? I think that is what you mean. The first true human had sex with the most immediate human ancestor. Neither probably realized that there was anything different about the other -- the closest human ancestor probably looked about like your average creationist. Even if we had living representatives of the 10 most immediate ancestors, we would be hard pressed to draw the line between 'human' and 'non-human.' (Which makes choosing the '10 most immediate' pretty difficult, but anyway...) Look at the debates today over whether certain genetically isolated salmon runs represent unique species and are thus qualified for endangered species protection. hw

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