Males are special

[Fred56]

In species that use sexual reproduction, the female has a full normal complement of chromosomes, the male has an almost normal complement with a single non-matching pair. These are the sex chromosomes. In the female, these are a normal matching pair of X chromosomes, with the usual double copy of each gene. The male has an XY pair of sex chromosomes, with no double copies (genes from the Y only are expressed and lead to the development of male physiology).

 

So the male seems to be a specialization of the female (apologies to the book of Genesis). This is further corroborated by observations that, in many species the male has a specialized role. In some, e.g. the lion, males do little more than provide sperm (the key purpose, perhaps, of sexual reproduction), while in others, e.g. some penguins, the male plays a close part in the nurturing process, during incubation especially. In humans, a study has found that, intellectually at least, females (the default genotype) fill the middle ground and males the start and end sections of the bell curve. This means that males are either stupid (low IQ) or intelligent (high IQ), and females are of average intelligence. Of course there are exceptions and this is only a single study, so far. But there it is guys, women can't be geniuses, only men have this potential.

 

We hybrids can be cheered by that, the downside being we are also potential dolts.

[PhDP]

In the female, these are a normal matching pair of X chromosomes, with the usual double copy of each gene. The male has an XY pair of sex chromosomes

 

I think it's important to note that it's not true for all animals. For birds, it's the opposite (female = ZW, male = WW) and hymenopterans (ants, bees, waps) use the haplodiploid sex determination system.

 

Honestly, I don't know how many animals use the XY system you're describing. Mammals do, but as less than 1% of all animals are mammals... Some species of insects also use this system, however.

[ydoaPs]

I think it's important to note that it's not true for all animals. For birds, it's the opposite (female = ZW, male = WW) and hymenopterans (ants, bees, waps) use the haplodiploid sex determination system.

 

Honestly, I don't know how many animals use the XY system you're describing. Mammals do, but as less than 1% of all animals are mammals... Some species of insects also use this system, however.

 

Does that suggest that sex has evolved multiple times?

[Fred56]

oops, yes perhaps I shouldn't have had birds in there, and yes, insects have a range of sex-determination processes, some animals use temperature (e.g. the tuatara lizard). I was being too general I see. The mammalian XY/XX sex chromosomes are well understood and the most familiar to people which is one of the reasons I didn't get into all the others. My mistake. I think the overall theme of my post still stands up though. I should have specified that this particular chromosomal sex-determination is found in mammals (which includes marsupials and monotremes, right?)

[iNow]

How does your proposal deal with XXY and XO syndromes, or the other in between areas on the intersex spectrum?

 

 

http://www.pbs.org/wgbh/nova/gender/spectrum.html

[Fred56]

Another question about this might be: how valid is the concept of “normal” genome or “specialized” chromosome? In mammals, certainly there is the appearance that the Y was derived or evolved from the X, but other animals have what looks like a differently evolved sexual-selection process, based on quite different arrangements of chromosomes.

 

 

 

In birds, the mechanism is not as well understood (are males the “default” genotype, or females? Do the sex genes switch on or off the sexualization, and of which sex? Does the male become a female, or vice-versa?).

I don't think you will find the idea of the male sex being derived from females mentioned in many biology textbooks, either.

 

How does your proposal deal with XXY and XO syndromes, or the other in between areas on the intersex spectrum?

 

 

By "my proposal" I assume you mean: the Y chromosome is a specialization, and so males are also "special" as in the title. Well, how does XXY syndrome detract from this, if that is what you think it does? XO sex-determination is found in some insect orders. Hope that isn't a Freudian slip there.

[iNow]

Do the sex genes switch on or off the sexualization, and of which sex? Does the male become a female, or vice-versa?).

I don't think you will find the idea of the male sex being derived from females mentioned in many biology textbooks, either.

I advise you look more into the terms "Wolffian duct" and "Mullerian duct." I've always thought it pretty commom knowledge that we all start out as females... which is why males are "special."

 

 

 

Here are two pretty useful links, and a quick quote from it to describe my reference above. Enjoy.

 

http://embryology.med.unsw.edu.au/Notes/genitalXXuterus.htm

The Mullerian duct (= paramesonephric duct, preferred terminology) paired ducts that form the epithelial lining of female reproductive organs: utererine tube, uterus, upper vaginal canal. The term "paramesonephric" duct means beside the mesonephric (Wolffian) duct, which is its anatomical location in early development. Mullerian refers to Johannes Peter Müller (1801-1858) a German scientist who specialised in comparative anatomy. These ducts initially form and then degenerate in the male.

 

 

 

http://www.bio.miami.edu/dana/104/104_sex.html

Yes, this means that in mammals--including humans--the female sex is the "default" pathway. We all start out as females, and only if a genetic "switch" is flipped do we become male.

The genetic "switches" are complex, but they involve the presence of very specific proteins on the plasma membrane of the cells, which act as portals for hormones (such as testosterone and DHT) to enter the cell and trigger the genetic events that cause an embryo to develop into a male.

[Fred56]

I've always thought it pretty commom knowledge that we all start out as females... which is why males are "special."

 

Interesting. My experience is that very few textbooks say this explicitly (maybe it's a "male thing" -most science writers are male), some sort of hint at it. That reference is the first time I've seen it written down in a specific way. Not sure how many people you would need to stop and ask before some one said "Oh yes, I know all about how humans, and mammals in general, all start out as female, and that the Y chromosome, which evolved from the X, is what produces a male". Where you did the survey would also make a big difference . Oxford campus or downtown London, say.

[iNow]

Where you did the survey would also make a big difference . Oxford campus or downtown London, say.

 

That's a good point. Even on a campus you'd probably encounter differences depending on which department you asked. I took a few semesters of human development and human sexuality, so it stood out pretty clearly in my mind. I think you're right that this knowlege might not be so common.

[Fred56]

just watching a doco about Passchaendale, the WW1 battle. My mother's father fought at the Somme, but was injured and shipped out so he didn't get to fight this one. So I'm here writing about chromosomes, which I got some of from him in my case. Just a weird incidental thing there.

 

Anyway I think it might be inaccurate to say that mammals "start out as" females, because each zygote, barring any problems, should have either XX or XY so already be male or not. Despite the sex chromosomes not starting up until later in the gestation phase, the sex is already determined at conception (as long as a Y is present, in the case of a male, and it hasn't undergone any crossover).

[SkepticLance]

The male mammalian embryo begins making testosterone very early in development, and this helps to guide 'maleness' instead of the opposite. This is vital, since the mother has oestrogen in her blood in abundance, some of which 'leaks' across to the embryo. Only lots of testosterone from that early time can compensate.

 

It has been suggested that, with repeated pregnancies with male offspring, the mother will generate antibodies against the mass of testosterone. That is why human males born after a bunch of brothers are more likely to be homosexual.

[Sisyphus]

. In humans, a study has found that, intellectually at least, females (the default genotype) fill the middle ground and males the start and end sections of the bell curve. This means that males are either stupid (low IQ) or intelligent (high IQ), and females are of average intelligence. Of course there are exceptions and this is only a single study, so far. But there it is guys, women can't be geniuses, only men have this potential.

 

That's not really an accurate description. Male and female both have normal "bell curve" distributions, it's just that males have a slightly larger standard deviation. Both sexes, in other words, are much more likely to be average, and both can be at either extreme. Males are just slightly more likely to be at the extremes. Of course, with that small a difference, it might say more about IQ tests than it does about intelligence.

[Fred56]

Here's what an article

http://www.dailymail.co.uk/pages/text/print.html?in_article_id=483707&in_page_id=1879

says:

 

But the Edinburgh psychologists have tested 2,500 brothers and sisters, all brought up to have the same high expectations, and given them tests in science, maths, English and mechanical ability. They have discovered that women tend to be better at languages.

 

By an overwhelming majority, however, the cleverest individuals - and the stupidest - in these tests tend to be the males. The females occupy the middle ground.

 

Timothy Bates, professor of psychology at Edinburgh University, who led the research, offered his own explanation: 'The female developmental programme may be tilted towards ensuring survival and enjoying the safety of the middle ground.'

[pioneer]

When male gamete cell's replicate and divide into sperm cells, we begin two complete sets of male chromosomes. These become halved, to form four sperm cells. Does this mean only half the sperm have the Y? Or do the Y also divide, to form four half-male sperm? Or are all combinations possible, such that we get male sperm, neutral sperm and gay sperm? Then is it off to the races, with one type having the highest energy? If the distribution is highly skewed could crowding alter the logical outcome? It is sort of like if the faster runner is at the back of the Boston Marathon, it can get boxed in, allowing slower runners to get to the finish first.

[Sisyphus]

Yes, I see what the article says, it's just obviously poorly worded.

[Paralith]

When male gamete cell's replicate and divide into sperm cells, we begin two complete sets of male chromosomes. These become halved, to form four sperm cells. Does this mean only half the sperm have the Y?

 

Stop right there. Yes. One diploid cell doubles it's chromosomes, then splits, and then splits again immediately, resulting in four haploid gametes. 2 will have the x, 2 will have the y. That's all the different "types" of sperm there are. And, while I'm at it, male differentiation begins at about 10 days post coitus, when the SRY gene on the Y chromosome begins to express, leading to the development of the urogenital ridge into testes, from which the rest of male differentiation results via hormones.

 

 

In humans, a study has found that, intellectually at least, females (the default genotype) fill the middle ground and males the start and end sections of the bell curve. This means that males are either stupid (low IQ) or intelligent (high IQ), and females are of average intelligence. Of course there are exceptions and this is only a single study, so far. But there it is guys, women can't be geniuses, only men have this potential.

 

As a woman, I think it goes without saying I personally dislike the idea that I'm incapable of being a genius. I'll be the first to admit that there are definitely inherent differences between males and females that aren't affected by the environment, but I still would like to see more data on this intelligence thing before I'll accept it. The definition of intelligence and genius themselves are still under debate as it is. Though I do think the distribution is interesting, as that's often what male to female reproductive success distributions look like. Take chimps, for example. There are the chimps that make it to the top and hog all the matings, and the chimps that are the losers and get practically none. But, every female in the troop gets her fair share of matings with the top male. This is largely why males are more willing to take risks when it comes to anything related to reproduction - they have a lot more to gain and a lot more to lose than females do.

[PhDP]

In humans, a study has found that, intellectually at least, females (the default genotype) fill the middle ground and males the start and end sections of the bell curve. This means that males are either stupid (low IQ) or intelligent (high IQ), and females are of average intelligence. Of course there are exceptions and this is only a single study, so far. But there it is guys, women can't be geniuses, only men have this potential.

 

What ?

 

It's well established that both women and men have an average IQ around 100, but the standard deviation for men is slightly higher. It doesn't mean women can't be geniuses, or that men are either stupid or intelligent, it only means the distribution is a little more homogeneous for women. And still, the standard deviation is quite similar.

[pioneer]

I don't think IQ tests fully expresses all forms of intelligence. There are artistic, emotional, managerial, social, athletic, applied, theoretical, intuitive, etc., If we did a broad based testing, using all these, the results would probably indicate that most people are idiot savants. The artist may not do well in applied science. The theoretical scientist may not do well in mechanical aptitude. The money manager may not be a good diplomat. None may have the emotional intelligence to be fully healthy.

 

If you look at male and female, one big difference is, only females can have babies. It would seem logical that female intelligence, is better geared to deal with needs of living biological computers, we call children and their husbands/boyfriends.

 

Picture if one is trying to program a futuristic living computer, and it decides to just walk out of the room, to collect other data. It is a free spirited entity, that is also sensitive and will shut down data input if you are not careful. You have to work with it, to get it to go back to work. But as it settles itself in, it accidentally breaks your monitor. If you freak out, it may generate an internal virus, that will adversely affect performance. One has to be firm, but loving, so the computer is happy helping you. When we finally make intelligent computers, females will dominate the field, since they are better equiped to deal with such complexities.

[Fred56]

I don't see that having females (the default genotype) fill a middle intellectual and presumably social position in a society where the males (the specialized genotype) fit in the "end-gaps" is a poor model or anything. This means the females would represent an overall mediating influence, between the dummies and the bright-sparks. This doesn't seem all that controversial. But it is only one study so it's maybe early days for definitive opinions. I haven't tracked down any online copies of the study itself so I don't know if males and females were analysed separately or what. So far I've only seen journalist reports.

[Sisyphus]

It's not that it's controversial (although saying so would be in most contexts), it's that it's not correct. Males have a slightly larger standard deviation, and so they are slightly more likely to be farther from the mean than females. That's it. If you got a different impression then that's just a result of bad science reporting.

[Fred56]

I see. But here is the study:http://www.subjectpool.com/ed_papers/2007/Deary2007Intelligence451-456_Brother_sister_sex_differences.pdf

 

And it does seem to be saying that males are more likely to be either highly intelligent or pretty stupid, compared to females.

 

Why is this so controversial? Why is it surprising that females, in the genetic stakes, are given the safety of the middle ground, and males get to gamble on whether they get good or bad intelligence. Males then fill specialist roles, like hunting, exploring and other risky activities, while the females provide stability, or however it works out. The idea of males as a specialization is where this thread started. That said, one of the journalists did describe Professor Bates as a "brave man", for publishing his study. There are a lot of other threads about this study, many with disparaging comments, to say the least. Go figure.

[PhDP]

And it does seem to be saying that males are more likely to be either highly intelligent or pretty stupid, compared to females.

 

Men are slightly more likely to have very high or very low IQ, it's exactly what I (and Sisyphus) meant by "the standard deviation is higher for men". They also say the same thing in your article. But what you initially said was very different;

 

In humans, a study has found that, intellectually at least, females (the default genotype) fill the middle ground and males the start and end sections of the bell curve. This means that males are either stupid (low IQ) or intelligent (high IQ), and females are of average intelligence. Of course there are exceptions and this is only a single study, so far. But there it is guys, women can't be geniuses, only men have this potential.

 

There's a big distinction between "women can't be geniuses", which is not true, and "they are less likely to have either very high or very low IQ", which is true to a certain extent.

[Sisyphus]

 

And it does seem to be saying that males are more likely to be either highly intelligent or pretty stupid, compared to females.

 

True enough. But the way you were saying it before, that males are either very smart or very stupid and females are average, is quite a different thing to say.

 

Why is this so controversial?

 

Because in human history women have only quite recently achieved equal social status with men, a status which is necessary for our modern society and yet still not completely secure. Thus talk of these kinds of differences often makes people uncomfortable.

 

Why is it surprising that females, in the genetic stakes, are given the safety of the middle ground, and males get to gamble on whether they get good or bad intelligence. Males then fill specialist roles, like hunting, exploring and other risky activities, while the females provide stability, or however it works out. The idea of males as a specialization is where this thread started. That said, one of the journalists did describe Professor Bates as a "brave man", for publishing his study. There are a lot of other threads about this study, many with disparaging comments, to say the least. Go figure.

 

It wouldn't be surprising, in my opinion. Of course, I'm also far from convinced that that is the reason for the disparity. After all, what would be the mechanism for "gambling" of intelligence? I would look first for other explanations in how, for example, testosterone affects psychology as it relates to things like IQ tests. Perhaps males simply "gamble" more in their choices (which goes along with the underlying idea of what you're saying), and when they gamble well they appear smarter, when in reality they were simply thinking more aggressively.

[foodchain]

You have to ignore culture to accept the argument. Be it eastern or western or other cultures you have certain cultural patterns, thoughts and or assumptions that have made things less the user friendly for female inhabitants. I don’t know if it applies directly to standard thought around sexism or racism but it is generally stupidism. There have been plenty of highly intelligent female whatever, be it scientists, politicians, humanitarians, the list can go on. Technically I think they whole argument as framed is a bit of an abused on the concept of the individual. Human beings period seem capable of being rather dumb or rather bright. It seems to be one of those things that heavily relies on environment, such as did you grow up in one that supported you being able to access intelligent people and resources cradle to grave, or did you get born to a war zone with a rifle in your hands. I don’t know how many star physicists come from such places these days.

 

Another thing which of course is impacted from the environment and of which should be common sense is interests. I have come to many standard conclusions held by biology all on my own, I can take various online chemistry tests and ace them, I have zero skill and doing physics:D Or so it would seem, and I hate math, well I don’t hate it, doing its actually quite relaxing I just hate how people frame it sometimes as the end all to everything or the perfect tool.

 

Yet in my math classes, of which I pay acute attention and of course focus, why is it I can be outdone by a female human? Why is it not always males being the smartest at everything at all times? I mean if we have a natural genetic advantage, or if somehow modern society and understand of say a refrigerator is in our genetic codes for example, such should show at a constant I would think... It would also I think then physically appear with females, but as far as I know females are perfectly capable of graduation in honors with degrees in mathematics and foreign language for example, which to me denotes a rather intelligent person. Plus plenty of females work in all branches of science in all tiers of society anymore.

 

For instance, genetically speaking. My wife’s ears lay almost flat against her skull, while mine have a different shape seeming to almost want to hear in front of me rather then to directly to my sides. I don’t think this really has any noticeable impact on me or her functioning in the world to be honest. Some people have better peripheral vision then others, but where does that imply and does it give any actual superior advantage in all reality.

 

Overall genotype to phenotype is not some perfectly understood facet of science. Also in all reality many times environment cannot be accounted for perfectly, more so in regards to people. So what you have typically is stupidity saying things like African Americans are not as smart as whites, or only men can be genius. What is a genius by the way? Some artist?

[Fred56]

What I said initially is what many science writers are interpreting this to mean too. While it isn't true that "only men" can be geniuses, most news reports do say "overwhelming" or similar things about the difference in representation. Since men are also "overwhelmingly" present in the dotards section, we aren't supposed to get to big a head-swell.

 

Perhaps males simply "gamble" more in their choices

 

Perhaps you misinterpret me. The metaphorical "gamble in the genetic stakes" that occurs during gamete fusion, is where I was going.