PZ Myers. 2005 Nov 01. Evolution of the mammalian vagina. <http://pharyngula.org/index/weblog/evolution_of_the_mammalian_vagina/>. Accessed 2008 Sep 05.
Posted on M00o93H7pQ09L8X1t49cHY01Z5j4TT91fGfr on Tuesday, November 01, 2005
Evolution of the mammalian vagina
Q: What unique organ is found only in mammals, but not in fish, amphibians, reptiles, or birds?
The title and that little picture to the left ought to be hint enough, but if not, read on.
A: The vagina. Aren't we lucky?
There's an old joke going around about poor design: what kind of designer would route the sewer pipes right through the center of the entertainment center? It's a good point. It doesn't make sense from a design standpoint to have our reproductive and excretory systems so intimately intermingled, but it does make a heck of a lot of sense from a purely historical point of view. In a sense, reproduction is an excretory function—we are shedding gametes produced internally, and we already have a perfectly good set of pipes running from our insides to the outside, so why not use them? It's just that in our lineage, which has specialized in giving great care to our gametes and zygotes, that plumbing has become increasingly elaborate, and that part of the system that was once just a convenient throughway has become a destination and a long-term residence in its own right.
Development tells us part of the story. The reproductive and urinary tracts are all tangled together in early development, arising together from two pairs of ducts, the Müllerian and Wolffian ducts, which are modified in complex ways to form a series of kidneys (we keep only the last one, the metanephros), one set of pathways for the male testes, and yet another set for the female ovaries.
In non-therian mammals, all of these complicated pipes have one common destination, a single outlet to the external world: the cloaca. "Cloaca" is Latin for sewer, and it is appropriately named. The terminus of the large intestine is here, as well as the ends of the ureters from the kidneys and the ducts from the ovaries or testes. Everything gets dumped in to the cavity of the cloaca, making a nice stew of feces, urine, and sperm or eggs. Mmm-mmm. The cloaca is the grey cylinder at the bottom of figure A, below, in the first three organisms, amphibians, birds/reptiles, and monotremes (my apologies for the murkiness of the image; it's the best copy I have).
The fundamental organization of the reproductive part of the vertebrate urogenital tract is straightforward: it's a tube with a funnel at one end that captures eggs released by the ovary, and conducts them to an external orifice. Along the way, cells lining the tube secrete useful products like albumin and yolk, and deposit a shell, and may act to temporarily store the egg before its final release.
Marsupial and placental mammals have dispensed with most of those functions, and expanded on others. One part of the oviduct has acquired a richly vascularized epithelium and specializations for investing and nurturing a resident embryo, becoming a uterus. That's an amazing and innovative function in itself, but in addition, it has formed a new, separate channel, the vagina. The vagina is an entirely new structure, which has no homolog in amphibians or reptiles.
That is an interesting observation. It's a wholly original structure that arose sometime after the monotreme-marsupial split, an evolutionary novelty. How did that happen? How can we study a unique event that occurred over 150 million years ago?
Wagner and Lynch have a proposal to answer both questions. The general mechanism for generating novel structures is evo-devo orthodoxy:
- An epigenetic side effect of other evolutionary changes in the body leading to a novel physical structure in the organisms.
- The genetic consolidation and individuation of the novel structure.
(Note that this proposes phenotype before genotype, which is somewhat heretical for neodarwinism. It shouldn't trouble the evo-devo gang in the slightest, of course.)
How to study such a process from the past?
The basic assumption of a molecular evolutionary approach to the study of evolutionary novelties is that changes in developmental regulation have left traces in the molecular structure of the genome and a comparative study of genomic structures should be able to identify genetic changes coincidental with a phenotypic novelty. (emphasis mine)
That process of consolidation and individuation would have left detectable scars in the genome—the genes involved would have acquired changes necessary to fix the phenotype in the population. Again, as we'd expect from the evo-devo perspective, those changes would have been made to the regulatory genes that control tissue-specific gene expression. What genes should we examine? Let's look at the therian organs of interest, and here are some likely candidates: the HoxA genes that have region-specific domains in the female reproductive tract.
Hox gene expression pattern and the evolution of the female reproductive tract. (a) HoxA-13 to HoxA-9 are located at the 5' end of the HoxA cluster and are expressed in the same regions in the adult as in the embryo: HoxA-13 (green), HoxA-11 (yellow), HoxA-10 (orange) and HoxA-9 (blue). (b) Tetrapod phylogeny showing representative female reproductive systems from each group (amphibian ovaries shown only on the left).
Phylogenetic relationships among a small set of vertebrate species including representatives of the major mammalian clades: monotremes (platypus), marsupials (opposum) and placentals (Hyrax and human). Above some branches the estimated number of non-synonymous and synonymous substitutions of HoxA-11. The estimates are obtained from a maximum likelihood codon model as implemented in PAML. Note that in the stem lineages of therians (i.e., the lineage leading to the most recent common ancestor of opossum and the placentals), there are five to six non-synonymous substitutions but no synonymous substitution. This indicates a very strong selection coincidental with the evolution of the internal developmental mode of mammals.
The HoxA-9 through HoxA-13 genes are expressed in order along the length of the embryonic Müllerian duct, and also continue to be expressed in adulthood; so the cells of the vagina are all expressing HoxA-13, while the cells of the cervix all have HoxA-11 turned on (for some reason, I find that to be a wonderful piece of knowledge, and I just have to say…Hooray for HoxA-13! It has just become my favorite Hox gene.)
So the question is whether there is any evidence that these particular Hox genes have signs of any set of changes that are associated with particular transitions in vertebrate evolution—in particular, are there differences that can be traced to the transition between monotremes and the theria, and between the placentals and marsupials. The answer seems to be yes: the diagram to the right is a measure of the number of synonymous to nonsynonymous changes in HoxA-11, which is an indicator of the selective pressures that have shaped the gene.
Furthermore, they've identified where these changes have occurred, and they are not in the homeodomain (the part of the protein that binds to specific sequences in the DNA, but in the amino terminal end.
Approximate positions of the amino acids positions of HoxA-11 which are under directional selection between the most recent common ancestor of all extant mammals and the most recent common ancestor of placentals. Note that all of these substitutions are N-terminal of the homeodomain and affect small clusters of amino acids.
The 3-D models below show where the relevant amino acids (in yellow) end up in the folded protein. The interesting thing here is that regulatory proteins don't just interact with each other, but also with other regulatory proteins that are simultaneously binding. It's a whole chain of interactions—regulatory proteins binding to the DNA, and also binding between each other in a complex called the enhancersome—that determines the level of expression of a particular gene.
HoxA-11 protein structure. This three-dimensional protein model was calculated by comparative modeling as part of the MODBASE project. (A) Model shown as ribbons. (B) Model rendered with a molecular surface. The DNA-binding homeodomain is shown in red. The carboxy-terminal region of exon 2 is shown in blue. Residues identified as being under directional (positive) selection in the stem lineage of eutherians are shown in yellow. Residues replaced in the stem lineage of therians but not identified under selection are shown in green. Note that all of these amino acid sites affect amino acids that are predicted to be placed on the surface of the molecule as expected if selection is driven by novel protein-protein interactions.
There is a great deal left to be done. Hox genes are rather high up the chain of regulatory genes, so there are many more genes downstream that have to be puzzled out. We also are a long ways from figuring out how these patterns of gene expression define the morphogenetic processes that create this lovely novel structure, the vagina. The important thing, though, is that there are these questions waiting to be answered—the investigators have a research program.
We propose that a research program to explain evolutionary novelties has to focus on the question of whether novel characters arise through the evolution of novel regulatory links among developmental genes. We further propose that a detailed analysis of the evolution of developmental genes involved in the development of a derived, novel character can reveal molecular changes that could be causally involved in the origin of evolutionary novelties. The case study presented here suggests that the statistical methods of molecular evolution are strong enough to provide specific hypothesis for experimental test. The success of this research program will depend on the ability to connect the patterns of molecular evolution with the functional role of these molecular changes.
That's the cool thing about evolutionary biology: exciting questions, titillating ancestors, and the promise of tools to answer more.
Lynch VJ, Roth JJ, Takahashi K, Dunn CW, Nonaka DF, Stopper GF, Wagner GP (2004) Adaptive evolution of HoxA-11 and HoxA-13 at the origin of the uterus in mammals. Proc Biol Sci. 271(1554):2201-7.
Wagner GP, Lynch VJ (2005) Molecular evolution of evolutionary novelties: the vagina and uterus of therian mammals. J Exp Zoolog B Mol Dev Evol. [Epub ahead of print]
Cifelli RL, Davis BM (2003) Marsupial Origins. Science 302:1899-1900.
Posted by PZ Myers on 11/01 at 08:02 PM
Science • EvoDevo • 4 Trackbacks • Other weblogs • Permalink
Science • EvoDevo • 4 Trackbacks • Other weblogs • Permalink
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HoxA-13. I'll remember that one...
Thank you - this is really cool! -
Reading this makes me want to sing TMBG's "Mammal"...
http://www.sing365.com/music/lyric.nsf/Mammal-lyrics-They-Might-Be-Giants/AA443679C3DF07A9482568B10028A7F8
Mammals are so awesome, and it is truly amazing to be a mammal. The male of the species gets short-shrift on this one.#: Posted by Mrs. Coulter on 11/01 at 08:52 PM -
... Hooray for HoxA-13! It has just become my favorite Hox gene.
but, can we sell soap with the slogan? -
actually, that's nifty. thanks, PZ.
blogs ought to have a way to go back and update them easily after new research is reported. -
This is wonderful (and you might be surprised to know that the thing that most interested me was the use of both molecular and fossil data in the evolutionary tree - a nice iconography), but it still doesn't tell me how to give my SO an orgasm...
#: Posted by John Wilkins on 11/01 at 09:21 PM
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... but it still doesn't tell me how to give my SO an orgasm...
well, y'see, you begin by ... oh, n'vrmind ... -
Superb as usual. Thanks.
#: Posted by on 11/01 at 09:37 PM
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Thank-you HoxA 13!!
I predict that a gene or cluster of genes for penis formation exists which has a parallel evolutionary history to A13... After all, the vagina and penis are complementary organs!#: Posted by on 11/01 at 10:18 PM -
Fascinating. I hadn't noticed that both fossil and molecular data was used in the evolutionary tree till Wilkins pointed it out. I enjoyed the fact that it showed, in an interesting fashion, how one can learn about events in the past... but I will remember HoxA-13!
#: Posted by on 11/01 at 10:23 PM
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Well, John first we have to establish if the current subject matter applies to your SO. Either way ..... may I suggest the classic, The Joy of Sex.
#: Posted by on 11/01 at 10:30 PM
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"but it still doesn't tell me how to give my SO an orgasm..."
Perhaps because the vagina is the wrong organ for that.#: Posted by on 11/01 at 11:45 PM -
I predict that a gene or cluster of genes for penis formation exists which has a parallel evolutionary history to A13... After all, the vagina and penis are complementary organs!
No, the penis has adapted to complement the vagina, but precedes it in evolutionary history. The penis is homologous to that other organ that John Wilkins is looking for.#: Posted by on 11/01 at 11:50 PM -
Ah, yes! That's right. I need to read my Gould, don't I?
#: Posted by John Wilkins on 11/02 at 12:39 AM
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Ah - another great job of speculative spin-doctoring!
Yet ANOTHER evolutionary research program! Just what we needed.
"We also are a long ways from figuring out how these patterns of gene expression define the morphogenetic processes that create this lovely novel structure, the vagina."
But, what if your given asssumption here is incorrect - What if there was NO morphogenetic process at work here? Don't you need to ESTABLISH this FIRST? (instead of assume it?)
"The important thing, though, is that there are these questions waiting to be answered—the investigators have a research program."
Hmmmmm. But are we asking the right questions? How could/would you design this research program that would produce some answers, and not just more speculations?#: Posted by Kevin Wirth on 11/02 at 01:23 AM -
Well Kevin, would you venture your own hypothesis that describes the above relationships that isn't just "Goddidit"? What does your hypothesis predict? What would your research program for this question look like?
Also, on their own the results PZ described are very strong evidence for evolution, and this is just a tiny speck of the total evidence supporting evolution. There is absolutely no reason why any of the above relationships should exist if evolution if false, except if God is just screwing with us.#: Posted by on 11/02 at 03:12 AM -
That's an interesting alt tag for the first image.
#: Posted by on 11/02 at 03:39 AM
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Typo: "opposum" (under the small phylogenetic diagram)
#: Posted by on 11/02 at 04:23 AM
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There is absolutely no reason why any of the above relationships should exist if evolution if false, except if God is just screwing with us.
But DrFrank, that's exactly the point. As Kevin pointed out, the human vagina is a big gap for God to take refuge in, and He took advantage of this about two thousand years ago...#: Posted by on 11/02 at 04:54 AM -
Kevin,
That's the cool thing about science, every time you answer a question, more questions flood in behind it. We need research, good research on cool topics like this keep mankind headed somewhere. Who knows where this research might lead? In fact, I'm pretty happy to know where it's gone so far...
And as far as the orgasm thing goes, last thing you wanna do is show her any of this material. While we evo-geeks might get off on it, her reaction might be less than positive.#: Posted by on 11/02 at 05:15 AM -
As Kevin pointed out, the human vagina is a big gap for God to take refuge in, and He took advantage of this about two thousand years ago...
Ah, so that's why you should keep it "unfilled". Sex push out god, who would have thought...
PS. My confirmation word was "Godless". How do you do it PZ?#: Posted by on 11/02 at 06:07 AM -
Ah, so you are diversifying! First cephalopod porn, then invertebrate porn, now tetrapod porn culminating in mammal porn!
To be serious for a moment, another very interesting and educating post! As others have said, this stuff is yet more evidence for evolution; it takes a very firmly closed mind to keep seeing it.
And back to silliness: my confirmation word for this post is "library", which is appropriate enough, since I'm posting from a computer in my university's library. The last time I posted on Pharyngula, however, the word was "perse", which is Finnish for "ass". Makes one wonder where you get all those words...
#: Posted by on 11/02 at 06:29 AM -
Those rascally Creationists will use such discussions to "prove" that all us evilutionists are frustrated, smutty little boys - and why weren't they invited.
Well done PZ. -
What if there was NO morphogenetic process at work here?
Er, what? Do you mean, what if the interaction of proteins created from the body's genes don't give rise to the vagina?#: Posted by on 11/02 at 07:54 AM -
What's next?...the evolutionary theories of female orgasm, including names such as Pole Ax, Upsuck, and Cuddles, which help solve problems with bipedalism, conception, and mate fidelity, respectively.
From the book "Sex, time and power: how women's sexuality shaped human evolution" by Leonard Shlain.#: Posted by on 11/02 at 08:01 AM - Umm, yeah, Hendy...there are vestiges of an earlier title I had in mind in the alt tags and some of the image file names. I revised in the interests of accuracy, since I am just talking about the vagina here. Now if I'd integrated a wider discussion of the whole vulva, on the other hand...
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Hmmm.........
If the avian cloaca is both an excretory and reproductive organ, then doesn't that mean any time birds have sex, it's automatically sodomy?
I'll be buggered - that penguin movie really was out to destroy Western civilization!
#: Posted by on 11/02 at 09:50 AM -
Excellent post PZ.
Whats sad is the comment in 46641 is so obviously close minded. Here is presented a solid bit of science but instead of learn something this poster clings to a ideology. I jumped over to his 'blog' and read more illogical mish/mash than any one human should be able to stand for a day.
It really makes one sad.:-(#: Posted by on 11/02 at 10:06 AM -
Frank,
"on their own the results PZ described are very strong evidence for evolution, and this is just a tiny speck of the total evidence supporting evolution. There is absolutely no reason why any of the above relationships should exist if evolution if false, except if God is just screwing with us. "
You know, it's just udderly (sic) amazing to me how imagination runs wild when it comes to building on evolutionary presuppositions. I mean, heck, the speculations are ENDLESS from Darwinists when it comes to imagining how this or that critter or organ 'might have' evolved. But when it comes to alternative types of speculations, these are verboten, not possible, not scientific, etc. etc.
To respond to your question about MY research program...
1) I don't have another 'research program' for the origin of the vagina because my speculation is that it didn't evolve. As for understanding the relationships of these organs, I have nothing to say except, why doesn't someone put on - just for the heck of it - the ID hat and try to speculate on the notion that it was designed.
We already know right off the bat that PZ thinks it's all a very "poor design".
"what kind of designer would route the sewer pipes right through the center of the entertainment center? It's a good point. "
So his bias clearly shows us that he is PREDISPOSED against this notion at the get go.
How scientific is THAT?
As for PZ presenting "very strong evidence for evolution", no, he most certainly has not done that. And to say so totally misunderstands the nature of evidence contrasted with speculation.
PZ has offered us some (as I called it) "spectacular speculations". That's NOT the same as EVIDENCE, anymore than a story about an alleged evolutionary pathway is the same as the HISTORY of what actually happened (another fantastic technique PZ has utilized elsewhere).
That's one the key faults of Darwinism - that you guys call speculations 'evidence' and even 'facts' as conveniently as I butter my toast in the morning.
Hey - speculation is good and a necessary part of any scientific reserach program. But let's make sure we keep our important distinctions. PZ hasn't offered us ANY evidence here - he has simply shown us how creative he is.
There's a HUGE difference.#: Posted by Kevin Wirth on 11/02 at 10:47 AM -
Patrick,
What if there was NO morphogenetic process at work here?
Er, what? Do you mean, what if the interaction of proteins created from the body's genes don't give rise to the vagina?
No. What I mean is, what if there are too many 'impossible' evolutionary hurdles to overcome? It's EASY to speculate endlessly ad infinitum only about evolutionary success, because it's assumed. If you can ONLY imagine evolutionary success for everything, and not come up with evolutionary impossisiblites, then are you really examining this issue as you should be?
I would say 'no', because anyone can imagine whatever they want to in accord with evolution. But unless and until you start thinking about why the vagina (or any other organ) could NOT have evolved, then you will never really come to grips with the true challenges on this or any other evolutionary issue.#: Posted by Kevin Wirth on 11/02 at 10:59 AM -
Frank,
"There is absolutely no reason why any of the above relationships should exist if evolution if false, except if God is just screwing with us."
Then I say, you're not imagining hard enough. AND, you're biased in that you are willing to expend a ton of energy imagining how evolutionary pathways 'might have' been generated, but you say you can't even BEGIN to imagine how the vagina might be 'designed' - unless God is messing with your mind?
My My. You give up so easily when it suits you.#: Posted by Kevin Wirth on 11/02 at 11:09 AM -
Then I say, you're not imagining hard enough. AND, you're biased in that you are willing to expend a ton of energy imagining how evolutionary pathways 'might have' been generated, but you say you can't even BEGIN to imagine how the vagina might be 'designed' - unless God is messing with your mind?
My My. You give up so easily when it suits you.
Let me see. You look at a part of human anatomy. Golly, it sure looks real complicated. So you (by your own admission) do not bother to speculate how it could have evolved, since you assume it couldn't have. You just slap a big "GodDesigner Did It" sticker on it, and bitch about everyone who hasn't 'solved' the problem the same way as you. And you accuse others of 'giving up'?
If you're turned off by the 'wild speculations' of people doing real evolutionary work, I would submit that one of ID's problems is that it has no speculation. No theory. None. All it has is "Evolution bad, it's all designed." It's a joke that's set up to always have the same punchline.
Try doing some real research. Whining about evil scientists isn't getting you anywhere.#: Posted by on 11/02 at 11:19 AM -
As for understanding the relationships of these organs, I have nothing to say except, why doesn't someone put on - just for the heck of it - the ID hat and try to speculate on the notion that it was designed.
Okay, Kevin- just for the heck of it, I'll put on the ID hat. It probably won't hurt much, since I'm not a scientist. Here goes-
Ow! My brain has no room!
Hey, it's not so bad anymore. I'm a real ID researcher now! Let's have at those questions:
The weewee? Designed. The peepee? Designed. The scientist? Designed. The creationist? Likewise. The Designer? Don't ask- it's a mystery.
Wow, this is real easy! I don't know why more scientists don't toss aside their silly books 'n' labs 'n' thinking caps, and join the fun!
Uh, no thanks- you can have your hat back, Kevin...#: Posted by on 11/02 at 12:01 PM -
I'm going to assume that Mr. Worth is a single male. Every woman, and every man who has lived with a woman, gets a reminder that the vagina and uterus were clearly not "intelligently designed" about once a month.
Also, leaving aside the issue of routing the plumbing through the entertainment center, what kind of "designer" puts the light switch on the outside of the room?#: Posted by on 11/02 at 12:01 PM -
PZ said: "what kind of designer would route the sewer pipes right through the center of the entertainment center? It's a good point."
Kevin Wirth responded
So his bias clearly shows us that he is PREDISPOSED against this notion at the get go...How scientific is THAT?
There's no evidence of "pre"-disposal in PZ's statement. He has considered the possibility of design and found what he considers to be evidence against it.
Maybe his premises are faulty, but the logical form of the argument is standard Modus Tollens: If designed, then poo and pee hole(s) separate from baby hole. Poo and pee hole(s) not separate from baby hole. Therefore, not designed.
KW: As for PZ presenting "very strong evidence for evolution", no, he most certainly has not done that. And to say so totally misunderstands the nature of evidence contrasted with speculation.
As you point out, speculation is necessary, but you seem to include a lot more under the speculation umbrella than you should.
Again, the premises may or may not be faulty, but the researchers reason that, if consolidation and individuation, then then the genome should show it. The genome shows it. Therefore, consolidation and individuation are a reasonable explanation.
As many have noted, this isn't exactly the most solid ground to be standing on. If the researchers reach the conclusion that 'therefore, consolidation and individuation are the true cause of the evolution of the vagina,' then, technically, they have committed the logical fallacy of affirming the consequent.
Anyone with a modicum of flexibility in their thought can take this as an explanation, compare it to other candidate explanations, and make up their mind about how good an explanation it is. It seems to me to be a rather good one, as it fits the data nicely; is consistent with the rest of evolutionary biology, which is strongly supported by loads of evidence independent of this particular study; it is more or less directly testable; etc...
If you can spell out how an ID "explanation" is better in any scientifically or philosophically relevant respect (nevermind doing so for the majority or all such respects), please do so. Otherwise, you'd do better to keep your simpleminded objections to yourself.#: Posted by on 11/02 at 12:22 PM -
What's next?...the evolutionary theories of female orgasm ...
well, PZ has already treated the orgasm in the human female from an evolutionary perspective. i'm too short on time to look it up, but it's around here somewhere and i'm sure it can be readily found by using the search function creatively. -
So his bias clearly shows us that he is PREDISPOSED against this notion at the get go.
evolution and morphegensis have been proved by overwhelming evidence for other organisms, organs, and systems. the only way it needs to be re-substantiated here is under the assumption that, for some odd reason, the rest of the human body was subject to evolution and the uterus and vagina weren't. that's not reasonable.
How scientific is THAT?
it's just as unreasonable to argue all other organisms evolved except humans, who were specially created. alas, i've seen that somewhere in the creationist bag of bad ideas, too. - Here, here, and here, for instance.
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Kevin said:
What if there was NO morphogenetic process at work here?
The article said:
We also are a long ways from figuring out how these patterns of gene expression define the morphogenetic processes that create this lovely novel structure, the vagina.
Given the context about Hox genes and gene expression, I'm pretty sure the morphogenetic processes that sentence is talking about are the processes that give rise to a vagina in a gestating mammal, not the processes that caused the vagina to evolve in the first place. In other words, your question is basically asking "What if the vagina does not develop during gestation from the proteins created from gene expression?" Perhaps you're implying that God poofs vaginas right into fetuses. Will that be the next target of creationists? First evolution, and then developmental biology? Are Hox genes the work of Satan?
But, hey, man, keep going on that reading comprehension thing. It's good to have something to strive for.#: Posted by on 11/02 at 01:02 PM -
noahpoah: If you can spell out how an ID "explanation" is better in any scientifically or philosophically relevant respect (nevermind doing so for the majority or all such respects), please do so
Well, "poof" is pretty succinct, you must admit ;) Also, at only four letters to evolution's nine, we should obviously accept it under Occam's Razor as the simpler explanation :D
Kevin, if you want to argue that evolution is incorrect, I'd like to see you take a stab at the plagiarised errors found in DNA http://www.talkorigins.org/faqs/molgen/ .
As an example, care to take any guesses as to why primates and humans share the same pseudogene meaning that mean we can't produce Vitamin C? We certainly need it to live, so our inability to synthesise it is a little crappy, especially considering that most other species can do it. Why do we have this broken gene, and why is it so incredibly similar to the one found in primates?
If I'm not thinking hard enough, limited as my imagination and intelligence obviously are, then why not illuminate us about your theories as to this unusual design?
In fact...
Puts ID Small Pointy Hat On
As a Creationist/IDiot, I hypothesise that God made these genes dysfunctional
a) so that Eve would eventually be tempted to eat the Apple (which contains a passable amount of ascorbic acid). On the other hand, why would He put in a broken gene rather than just not inserting one at all?
b) because it was a fitting punishment to condemn post-Adam/Eve humans to eat fruit to remind them of what they had done. He also did it to primates because they looked annoyingly similar to humans, a fact he hadn't realised until he compared the two after production.
c) because it's a fact, and I know God did it, so he must have done. I've no idea why or how, though, and have not a shred of evidence to suggest that this is the case.
I'd go with b) as the better hypothesis, personally: it explains the broken gene quite effectively. If it ever gets into AiG, I want full credit.
Now, to gather `evidence' for this I'm going to wander off and read the Bible *toddles off*
My My. You give up so easily when it suits you.
And you don't even try at all, I fear.#: Posted by on 11/02 at 01:23 PM -
Kevin wirth
'Then I say, you're not imagining hard enough'
and then
', it's just udderly (sic) amazing to me how imagination runs wild when it comes to building on evolutionary presuppositions'
Hmmm, a conflicted human being. Science makes use of imagination also, it calls it thinking about what is real and how it came to be that way. It doesn't stop at 'ID did it' and take a nap. Why? because ID did it is not an answer.
ID did it can easily be substituted for anything, FSM, Santa, etc. We don't have that avenue in legitimate science.#: Posted by on 11/02 at 01:24 PM -
Well, "poof" is pretty succinct, you must admit ;) Also, at only four letters to evolution's nine, we should obviously accept it under Occam's Razor as the simpler explanation :D
That's nothing. I have a much better explanation: I am God. I created the universe and everything in it, and then in the summer of 1983 I incarnated myself as a human for reasons I don't remember, and lost all my omniscience and omnipotence. My evidence for this? The sound I made while creating the universe was not "poof", but "zap", making my explanation one letter more parsimonious than yours.
You're all just lucky I'm so easy to worship for. Books is all I ask, really. Wild Cherry Pepsi wouldn't hurt, either. And money is always appreciated.#: Posted by on 11/02 at 02:08 PM - Does the female pirate experience an orgasm or an arrrrghhhasm?
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I find this article inappropriate.
#: Posted by on 11/02 at 02:32 PM
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Oh oracles of biological wisdom, my mammalian-reproduction-related question is this: in the words of MoDo's paraphrase of Thurber, Are Men Necessary? Surely in some limited way, the answer is No: if men were reduced to their male-gamete-carrying essence, then sexual reproduction with all its advantages would still happen, but there would be more resources available for women and children. There are species with sexual dimorphism of this kind, but the vague question is, why doesn't this happen all the time, or more often, or with people?
#: Posted by on 11/02 at 03:07 PM
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" I find this article inappropriate."
What a bad and empty sentiment to put on a biology blog!
My take is that PZ describes something that is readily available for my amateur study and that I can really get into.
#: Posted by on 11/02 at 03:58 PM -
" I find this article inappropriate."
What a bad and empty sentiment to put on a biology blog!
Um, I think he was making a joke. It was an allusion to the Albertson's market chain pulling that issue of Seventeen with the article about women's, uh, plumbing.#: Posted by on 11/02 at 04:09 PM - Fantastic post!
- Now you've done it. You won't be able to publish this blog at Albertsons.
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"Um, I think he was making a joke."
Oh I see now, thank you. I hadn't looked into that posting; US prudishness is amazing and boring at the same time.
And selfdefeating; I remember reading a US magazine long ago there a girl said that she was a virgin since she only practised oral and anal sex. The latter was at the time considered advanced sex of course, and is riskier to the subjects health.
I dont understand a culture that thinks the absence of information is good and useful information...#: Posted by on 11/02 at 05:26 PM -
Oh man... I don't even want to see what happens when your buddy Bitch Ph.D. finds out that you referred to the vagina as an "entertainment center".
;) - Pshaw, Dr. Dave, the vagina is the center of a great deal of entertaining activity.
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Patrick: That's nothing. I have a much better explanation: I am God. I created the universe and everything in it, and then in the summer of 1983 I incarnated myself as a human for reasons I don't remember, and lost all my omniscience and omnipotence. My evidence for this? The sound I made while creating the universe was not "poof", but "zap", making my explanation one letter more parsimonious than yours.
But you'll eventually lose out to "Go" Creationism and you know it :D
On a similar note, I do like to posit the hypothesis that I will create all life on this planet by building a time machine at some point in my life, going back, and appropriately seeding the primordial soup so as to aid abiogenesis. The great thing is that this hypothesis is intrinsically falsifiable, as you just need to wait until I die to falsify it, and that automatically puts it above ID in terms of science :D
I may also go back sometime a bit later and add a flagella if they don't already exist, just in case. I already know enough biology to use bits from the Type III secretory system, and I'll just cobble together the rest from whatever's lying around...#: Posted by on 11/02 at 07:01 PM -
But you'll eventually lose out to "Go" Creationism and you know it
Nuts to that, man. I'll just recreate everything with that African click noise that gets written as '!'.#: Posted by on 11/02 at 08:50 PM -
ts said:
No, the penis has adapted to complement the vagina, but precedes it in evolutionary history. The penis is homologous to that other organ that John Wilkins is looking for.
i know of various pre-mammalian intromittent organs, but i'm not sure about homology to the mammalian. i recall an earlier posting about the many ways to evolve a penis... was it here or ??? (anybody remember?)
but in reference to "that other organ"... where in the evolutionary tree does the clitoris originate? (do lizards have them? salamanders?)#: Posted by on 11/02 at 09:13 PM -
"why doesn't someone put on - just for the heck of it - the ID hat and try to speculate on the notion that it was designed."
Ok ... Maybe it was designed.
There, that's taken care of, now let's get back to not being unimaginative morons.#: Posted by on 11/02 at 09:30 PM -
"Um, I think he was making a joke. It was an allusion to the Albertson's market chain pulling that issue of Seventeen with the article about women's, uh, plumbing."
Yeah, it helps to check "Albertson"s email address:#: Posted by on 11/02 at 09:40 PM -
. Please stop.
#: Posted by John Wilkins on 11/02 at 09:47 PM
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A great article. Thank you!
I've read far too many articles and books on biological issues that just kind of gloss over vaginas (and the whole Pink Bits Area). Hey, I like mine, and want to know more about it.#: Posted by Miss Sonia on 11/03 at 02:03 AM -
OMG!
>... but it still doesn't tell me how to give my SO an orgasm...
Come on PZ, we ALL know this is like a really good dragon punch combo, it's about recipe, timing, and small variation. So please, we know that you know things, and it's just fair that you share em!#: Posted by teh stra4ng3r! on 11/03 at 03:12 AM -
OK Boys n Girlz, enough vaginal entertainment for a minute.
It's movie time!
Take a look at this:
go to http://www.arn.org to view a pretty amazing video
See the blue box with the title: "Looking for More Information About Intelligent Design" (about 1/3 of the way down the list of links)
When you're done, there'll be a test and a prize for the best answer!
(a little better than a crackerjack prize too...)#: Posted by on 11/03 at 04:23 AM -
So Kevin, what are your views on the following questions? ID contains a large number of contradictory views, and it would help to know which one you hold:
a) Are humans descended from primates?
b) Do all organisms share a common ancestor?
b) Is the Earth about 4.5 billion years old?#: Posted by on 11/03 at 05:03 AM -
Hmm, I'd like to rephrase a) as "Do humans and modern primates share a common ancestor?": it looks a bit like I'm talking about "missing links" in the original version.
#: Posted by on 11/03 at 05:15 AM
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Uh, Kevin, if you want us to click on all 26 links in the box "Looking for more information about intelligent design", you had better tell us what the prize is first. If you meant just one of these links, how about telling us which one, or is that the test?
And I'd be happy to hear your answers to any of the questions you've been asked here. Or you can answer mine: if ID is a scientific theory, what predictions has it made that have been substantiated? Hint: saying that some feature is "complex" or "designed" is not a prediction.#: Posted by on 11/03 at 05:39 AM -
There's not a whole lot of reason to do so, but if you do poke around that website, there are some amusing examples of the kind of cognitive dissonance/inability to stick to one story that we've come to know and love from ID types. For example, they have this blurb in regards to the recent decision from the state of Victoria:
TheAge.Com.au reports that Victoria's government schools will treat intelligent design as a religious faith, not science, Education Minister Lynne Kosky has ruled.
In her first statement on the subject, Ms. Kosky reaffirmed the principle that government schools were secular and did not promote any religion.
This ruling again shows where the strategy must focus: it's science vs science, and this message must be spread. Intelligent Design Theory scientifically seeks to find out whether something in the cosmos came to be from natural causation or intelligent agency. The causes of something could be natural or intelligence, or a combination.
...where we get their usual weasel words about "ID is not religious! How could you think that?
Versus the following blurb, where they reassure the true believers where they really stand:
The bacterial flagellum, long the "poster child" of the ID movement, is described in stunning detail in a 34 minute movie made by the Nanotechnology Researchers Center of Japan. The link above contains the movie. To read a report, click HERE.
I don't have enough faith to be an atheist...
...And of course, luminaries like the DI, Denise O'Leary, and Dembski are all over the site.
It's basically another AIG spinoff, tho this time with somewhat more scientific pretensions and less Jesus.#: Posted by on 11/03 at 12:38 PM -
So what?
This is the closest to pussy that you, as a hopeless tosser, will ever get in your entire life!#: Posted by on 11/03 at 03:53 PM - okay, guilty, what's a "hopeless tosser"? i don't speak English, apparently.
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Slang for, roughly, a pathetic loser with no social life. `Tosser' strongly implies the inability to get a girlfriend, hence the need for, er, single-person frustration reduction.
(I've been a frequent target for this term. Probably every adolescent male in an outgroup at an English secondary school has.)#: Posted by on 11/03 at 06:35 PM -
I don't know if I really understood a word I read. Sounds like a excellent example (proof) of intelligent design. Someone did some damm good planning. Thanks God.
#: Posted by on 11/03 at 08:47 PM
- That figures. Incomprehension is the usual route straight to God.
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The incomprehension thing here is that it does take two to reproduce. So, you chose to believe that some species of a creature evolved and developed a penis and at the same time another member of that species evolved and developed an vagina. And, these two creatures living on Plant earth happened to find each other and multiplied.
#: Posted by on 11/03 at 10:22 PM
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... some species of a creature evolved and developed a penis and at the same time another member of that species evolved and developed an vagina.
yeah, why is that, g-bunch-of-small-digits? why isn't all reproduction parthenogensis, according to creationism, that is? -
Hey, half way thru this ARN weblink presented by Kevin, and of course applying good old rhyme, reason, and rationale, I'll pretty much sum it up this way, its appalling to see educated people abandon reason and scientific conclusions for mere spin and speculation, in the name of having blind faith
Well... all I can say is site does seem to be all about attractive cartoons, animations, spins, advertisements, propaganda disguised as "science" than real hard facts or experimented-proved conclusions, probably geared towards misleading the un-informed and un-aware public. More of a publicity stunt to me.
I see they have all these fancy books and cartoons and animations, how come none of our scientific institutions are publishing materials aimed to inform and educate the masses?, ideas like cute cuddly finches stuff dolls and children's books and comics??
Can't we just get good old Bill Gates to finance it all, for the benefit of science? or has he been brain-whacked by the IDist....omigosh!
viji#: Posted by on 11/04 at 01:54 AM -
yeah, why is that, g-bunch-of-small-digits? why isn't all reproduction parthenogensis, according to creationism, that is?
Well, ekzept, there was that one time, about two thousand years ago. Of course, that would mean the New Testament was mistaken about Jesus' gender...
And, these two creatures living on Plant earth happened to find each other and multiplied.
g-bunch-of-small-digits, you are going to have to tighten up your logic a bit. We can't respond to claims that are so muddled they're not even wrong.#: Posted by on 11/04 at 02:20 AM -
That first diagram looks like the evolution of headphones.
#: Posted by on 11/08 at 03:52 PM
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I'm afraid I've linked to this article with the hypertext 'Is Pat Robertson an expression of the HoxA-13 gene?'
#: Posted by on 11/11 at 06:20 PM
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Looks like a design by committee...
By the way - here's why men <b><i>LOVE<b><i> those Dodge trucks! Click it:
http://revart.blogs.com/photos/art_wheels/dodgetrucks.html#: Posted by Rev. Art - Minister of Rants on 11/13 at 11:01 AM -
Rev Art.
Effing brilliant, catching that. Did the Dodge Ram logo evolve convergently with the vagina, or is it an example of intelligent design?#: Posted by on 11/13 at 12:33 PM -
Re " plumbing in the entertainment center", I am reminded of W.B. Yeats' famous line "Love has pitched his mansion in the place of excrement".
Don't forget that other little uniquely mammalian organ, the neocortex. And its thalamic organist (read the book by Murray Sherman and Ray Guillery).#: Posted by paul adams on 12/10 at 07:05 PM - A brilliant insight, Rev. Art! That was hilarious! btw, if mammals are the only animals with vaginas, why aren't we called "cuntals" or something instead of "mammals"? Is it because Linnaeus was a tit man?
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That's the cool thing about evolutionary biology: exciting questions, titillating ancestors, and the promise of tools to answer more.
"Cuz the Good Lord made it that way" isn't a sufficient answer for you?