"...????....then that that that's a dingle berry?"
Posted on 09/16/2013 3:32:09 PM PDT by neverdem
The idea that men and women are fundamentally different from each other is widely accepted. And throughout the world, this has created distinct ideas about which social and physical characteristics are necessary in each gender to maintain healthy human development.
However, social revolutions throughout the last century have challenged traditional ideas about not only which traits are normal and necessary for survival, but also how humans acquire them. Thanks to a new study from researchers at Case Western Reserve University, science is continuing the charge.
By studying rare families in which a daughter shares the same Y chromosome as her father, Michael Weiss, MD, PhD, and his colleagues at the university's School of Medicine have determined that the pathway for male sexual development is not as consistent and robust as scientists have always assumed.
A team led by Weiss, chairman of the Department of Biochemistry, the Cowan-Blum Professor of Cancer Research, and a professor of biochemistry and medicine, has published a study in the Proceedings of the National Academy of Sciences that examines the function of the SRY gene. This gene is responsible for initiating the process that leads to male development.
"A general principle of developmental biology is that evolution favors reliability," Weiss explained. "Robust switches ensure that our genetic programs give rise to a consistent body plan to ensure that babies have one heart, two arms, ten fingers, and so forth."
Traditional viewpoints emphasize the uniformity of this process. The new research indicates that male sexual development is less stable than other genetic programs.
In fetal development, a gene located on the Y chromosome, called SRY, begins the process that leads to male development. All fetuses initially develop with female tissues, no matter what the sex will be at birth, so the master switch is responsible for initiating the transformation of female tissues into male tissues. From there, the testes develop and produce testosterone, which eventually forms the male's external genitalia.
The university's study employs mutated SRY genes shared by a father and a sterile XY daughter. Females usually develop with an XX pair, but, in these families, the father instead produced a daughter with an XY pair. This occurs during fetal development when the SRY gene's master switch fails to trigger. Internal female tissues, such as the uterus and fallopian tubes, continue to develop but are dysfunctional and infertile.
"Yet the father has the same Y chromosome and the same mutation as the daughter," Weiss pointed out. "And since he is a fertile male, we know that the switch must be poised right at its edge."
The team decided to measure the biochemical threshold of the SRY master switch.
"Our expectation was that we'd find that a factor of 100 or more—a severe insult to the Y-encoded switch—was necessary to alter development," Weiss said. "But what we found was that the SRY threshold, as probed in father-daughter pairs, is only a factor of two."
Therefore, human males actually develop near the edge of sexual ambiguity. This means that, unlike the robust genetic programs which develop other essential processes like heart function, the SRY gene master switch is particularly vulnerable to change. It only takes a slight deviation from the normal process to dramatically alter fetal sexual development.
Given the importance of sexual reproduction to the survival of a species, why do human SRY genes function so close to the boundary of infertility? The idea of an unreliable master switch might appear paradoxical, but a growing body of research suggests that it might be an evolutionary necessity.
Extensive studies of gender-associated styles of childhood play and the acquisition of social competencies by Dr. S. Baron-Cohen and colleagues at Cambridge University (UK) have highlighted the long-term effects of testosterone secretion by the fetal testis. Testosterone influences the patterning of the male brain during a critical window in human development.
And it is the SRY gene that sparks the genetic program leading to the formation of testes and the production of fetal testosterone.
"We have this tenuous switch on the Y chromosome, and we anticipate that its gift to humanity is variability in the pathway of male development from its earliest stages," Weiss said. "The essential idea is that our evolution has favored a broad range of social competencies. In prehistory, this range would have given a survival advantage to communities enriched by a diversity of gender styles."
In fact, certain aspects of modern history seem to parallel this idea.
Susan Case, PhD, a professor of organizational behavior at Case Western Reserve Weatherhead School of Management, who was not involved in the study, agreed with Weiss's argument and noted that "diverse mixes of people offer more varied perspectives, more ideas and solutions, and more challenges to long-accepted views." In the corporate world, for example, these differing styles increase creativity and problem solving, especially within a group.
The implications of Weiss's research suggest that elements of human culture, which had been assumed to be psychological or cultural, may be biological, instead. Therefore, human evolution would not have been dependent on consistency and homogeneity, but on their exact opposite.
Source : amanda.petrak@case.edu
It is impossible for a male cat to be “calico”
Keep on smokin that stuff!
Leftist feminazi prof promoting a path to another false science of consensus that being gay is a genetically programmed behavior. Born that way... can’t be cured... you know... the new agenda.
"...????....then that that that's a dingle berry?"
Fragile X Syndrome has nothing to do with the X chromosome breaking. In the mutation, the X has a large number of serial tandem repeats. It’s named for the appearance this gives it on staining, with a separated piece due to the unmarked section.
Laughable and absurd conclusions from half-baked academics desperately trying to spout the party line in order to get funding. Lysenko would be proud.
The simplest explanation for the findings, and the explanation most concordant with prior knowledge and observed nature, is that the failure of a few males to achieve reproductive success is immaterial, as the number of females is invariably the real population bottleneck.
Mammalian life is replete with examples of species that effectively write off a significant portion of males as genetic dead ends. Polygamy is the norm among many higher mammals, as well as within primitive human societies (along with polygyny), so a genetic abnormality that causes a small fraction of males to fail to reproduce will face orders of magnitude less selective pressure than a similar abnormality on the female line - especially if such failures to masculinize were chiefly due to interference from strongly-selected-for maternal traits (i.e. mitochondrial DNA influences, the “Mother’s Curse”).
It’s absurd to claim that such conditions are actually SELECTED FOR, or even more laughably that they provide a significant level of benefit due simply to the laughably assumed benefits of “diversity”.
Actually, my mom had two gay cats. I swear!
I grew up on a farm. Whatever happened to just lifting the tail up and giving it a gander?
I think we are being punked here.
Sacha Baron Cohen, perhaps?
ok good
Give it a taste test.
They are saying this is why Rosie O’Donnell has hair all the way down her back and chest.
lol
Oh THAT’S what this garbage is about
.....and why Michelle Obama has a penis
.....and why Michelle Obama has a penis
Laying the groundwork to support the notion that homos are an important part of human society.
The article moves from actual science to PC propaganda. Weiss is studying how an embryo becomes male or female — a biological process complicated enough that it can go wrong sometimes. This is biology, based on experiment and observation. Billthedrill explained the basics. Baron-Cohen is studying autism and sex differences — how the biology translates into behavior. Still science, but complicated science because it involves human behavior. Then Susan Case from the School of Management brings in the party line. To confirm your stereotypes about her, check her web page http://weatherhead.case.edu/faculty/Susan-Case/
well I have wondered why she stands with her feet so far apart
nooooooooooooooooooooooooooo!
unsee
unsee
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