-- The answer may depend on mom's eating habits.
| Quote: |
The reason food intake may influence the development of one sex of infant rather than another isnt fully understood. However, in vitro fertilization studies show that high levels of glucose encourage the growth of male embryos while inhibiting female embryos.
It may be that male embryos are less viable in women who regularly limit food intake, such as skipping breakfast, which is known to depress glucose levels. A low glucose level may be interpreted by the body as indicating poor environmental conditions and low food availability, the researchers said. |
Read on
. This study has been much misreported. The main problem is that the University press release was flawed.
If you read the original abstract from the paper you get: | Quote: |
| Intakes during pregnancy were not associated with sex, suggesting that the foetus does not manipulate maternal diet. |
The University press-office then mangle this to read; | Quote: |
| there is still no evidence that diet during pregnancy, rather than around the time of conception, plays any role in the sex of a fetus. |
This is simply a case of unintended distortion of an otherwise perfectly good piece of science (ie that what the mother eats PRIOR TO CONCEPTION is a determinant in the eventual sex of the baby).
http://journals.royalsociety.org/content/w260687441pp64w5/
PS - I didn't mean to imply that you (Prole) were presenting a distortion of the study - simply that the study has been widely misreported as meaning that pregnant women can alter the sex of their child through diet. Didn't the sperm cell determine the sex of the human to be?
I think that the media-hyped article asserted that certain diets may make the environment more acceptable to XX or XY sperm. So, gender is still based on the sperm, but survival of the sperm is based on diet.
It sounds like a bunch of BS though...
Yea, its a media hype... The exact mechanism of sex determination is yet to discover..
Brazilian media has been talking a lot about it... maybe because our popular wisdom always said that. "Each a lot of lettuce if you want a female" (or male, I don't know) etc.
I have heard that eating lots of meat would have higher chances of getting male and eating lots of veges would lead to having female. I think its about the link between food and hormones...
my boyfriend has told me sometimes about what he knows, I'll try to tell you the best way I can.
I think it was after the menstruarion stops the chance of getting a boy is much bigger, if it was the eggcell or hormons that had an impact I can't remember, I'll ask him later and see how it was again, it was a little confusing the first time I heard it. He means that the chance of getting a girl is bigger than a boy.
I'll get back on this later
I do believe there are some factors that may increase the chances of conceiving a gender, but I don't think they are enough to overpower the certain randomness of sexual insemination. With much of the world's obsession for male offspring, if something increased the chances of a boy, however so slight, it would be wide known.
The only thing I know of a specific gender is in reptiles where it is related to temperature.
I'm doing work on some factors of sperm competition this summer, I'll see what I can find as it comes to gender. Hopefully I get results but it's more than likely I won't because I don't think something like this can be so elegantly discovered.
I was under the impression that the gender is 'determined' in the sperm? And the sperm is already a 'male-sperm' or 'female-sperm' while in the male before intercourse...or does that get determined after intercourse/insemination/etc.?
I actually think it would be a good idea that this remain unknown on what determines the human gender during birth.
I think if we figured out how to change it to what we want, our world might end up with a lot more Males/females than there should be.
I think keeping it at random is best, and much more of a surprise.
Just my opinioin though.
Did the original study say how much the diet affected the male/female ratio? Are we talking about 90%-10% or 51%-49%?
To GhostRider103:
Is it preferable to have a "random" chance for a male/female and then kill an unwanted child of the "wrong" sex or is it better to be able to produce the "correct" sex? Difficult question. I know that there are many children born of the "wrong" sex who have had very unfortunate lives because they were unwanted.
The sperm determines the sex of the baby, and there are male-sperm and female-sperm and that is determined before sex (ie when they are produced in the man's body). I'm sure there are factors such as female-sperm are more 'hardy' at a slightly different temperature, and certain lifestyle factors can affect the ratio. But I'm sure I remember details of a study (or few) that the boy/girl ratio is changing as before we needed lots of girls due to high infacnt mortality and girls are needed to continue to reproduce but now we are evolving to produce more boys. Pretty sure I got it the right way round but can't find a reference off hand (although admittedly not looked very hard as not on usual computer).
David.
Just wanted to suggest that before you all make some pretty broad assumption about gender, you may want to consider the possibility that gender is not quite as you think of it. There are plenty of people that medicine cannot really classify as either gender.
I refer you first to the study of Dr. David Page, et al., "The sex-determining region of the human Y chromosome encodes a finger protein," in Cell, no. 51, pp. 327-360.
They claim that a section of DNA codes for gender, but base their assumptions on a small sample size of men with XX chromosomes and women with XY chromosomes. By their mere existence, these people challenge some of our societal notions regarding sex since the gender designations they have been given are somewhat arguable since the "men" for example do not exhibit all the traits of a typical male, i.e. inability to produce sperm.
As a good follow-up, and probably the more important article if you're going ot read one is
Anne Fausto-Sterling, "Life in the XY Corral," Women's Studies International Forum, Vol 12, No. 3, 1989, Special Issue on Feminism and Science, p. 328.
i was a taught when i was in school that its the sperms and the chromosones which determine the sex of a child.
god knows what else they will come up with now
So what dietary factors are more prone to contribution to a boy and what dietary factors contribute to the formation of a girl?
This seems like a false claim. I agree that diet can affect fertility and conception, however this seems false.
It is not like the caloric/nutritional intake requirements are different at the formation stages. Girls in general are smaller and have less caloric needs relative to the male population, but they do not require different nutrition.
The hypothesis is based on the fact that male children carry a higher burden in evolutionary terms. It is more 'efficient' from a species point of view to produce a higher proportion of females, and therefore one might expect to see more female babies born unless there is a plentiful supply of resources (specifically food). The hypothesis is, therefore, that in times of plenty one would expect to see more male children and in hard times (poor nutrition) one might expect to see fewer male children...
Obviously within a week or two they'll be selling diet plans to help someone supposedly have a girl or boy specifically. 
I'll leave this to the researchers; I am nincompoop on the subject. And I'd also like it to remain random and a surprise, else you'll not see a single girl child in societies where a girl child is considered inferior.
| Bikerman wrote: |
| The hypothesis is based on the fact that male children carry a higher burden in evolutionary terms. It is more 'efficient' from a species point of view to produce a higher proportion of females, and therefore one might expect to see more female babies born unless there is a plentiful supply of resources (specifically food). The hypothesis is, therefore, that in times of plenty one would expect to see more male children and in hard times (poor nutrition) one might expect to see fewer male children... |
Hi Chris:
It just seems like this would be more like an old-fashioned idea, one that would support things like sexism of a deeply biological kind; one that fosters things such as favoring male children and discarding or aborting female ones.
Rather than this being an appeal to consequences, the idea itself seems like pop-science that is not based on how nature really works and that is why it could be the basis of false belief paradigms.
How do the male children carry higher burdens in evolutionary terms? The dietary requirements for boys and girls in childhood ages is really not THAT different. Besides, even if there was a higher evolutionary burden, that would be offset by the benefits of strength that the boys contribute (protection, power, etc.).
It is therefore does not seem to be all that cut and dry to say that females are more in demand when conditions are less than desirable. While it can be seen that females would require a little less food (but not THAT much less), the strength of the boys as protectors, builders, hunters, etc. would make the need for boys in such a situation just as great as to balance the evolutionary need for girls.I would have thought the logic was self-evident. We measure success in biological terms by 'fecundity'. Now, tell me, which species grouping will increase numbers more rapidly:
100 Males and 100 females or
20 Males and 180 females ?
(Given, of course, that social factors such as monogomy are not influential).
The hypothesis is not unreasonable. It might be wrong - that is why we do experiments to try and find out. Just because an hypothesis is troubling to our modern sensibilities does not mean it should be discarded - we do not behave 'naturally' in many many ways and nobody is proposing that we should. I'm not personally in favour of killing the disabled, letting the weakest starve, or having rule by the strongest physical specimens. The point of knowing is, first and foremost, to know.
