GENDERCENTRIC

Karyotype or Stereotype

Karyotype or Stereotype

The human karyotype[1] is a familiar image to most of us, a piece of iconic pop art as recognizable as the London Underground Map, and, perhaps, with a similar approximation to street-level reality. (As many visitors discover the London Underground map has a very loose relationship with the situation above- ground.)

However, for most of us the familiar narrative of chromosomes has long seemed perfectly plausible, and good enough for purpose.

The human karyotype[2] is a familiar image to most of us, a piece of iconic pop art as recognizable as the London Underground Map, and, perhaps, with a similar approximation to street-level reality. (As many visitors discover the London Underground map has a very loose relationship with the situation above- ground.)

However, for most of us the familiar narrative of chromosomes has long seemed perfectly plausible, and good enough for purpose.

The story goes something like this. All humans have 23 pairs of chromosomes of which 22 are composed of almost identical pairs. The other pair is special in that the two partners in the chromosome pair look very similar in women, both being called X; whereas the two partners are very different in men “a large single X accompanied by a shrunken vestigial chromosome called, with alphabetical logic, Y”. [3] Sex is determined by chromosomes inherited from our parents. Women have a pair of X chromosomes, having got an X from both parents; whilst men have X and Y having got a Y from their fathers. So far, so good.

We have become very comfortable with the biological metaphor XX/XY to explain a variety of social hierarchies and behaviour. Books have been written about it. But some scientists now state that the binary XX/XY model of chromosomal sex, our karyotype tube map, was simply a reflection of existing sex and gender stereotypes of dimorphism “projected onto chromosomes by early researchers”. Nonetheless this idea of binary sex hormones has seized the public imagination and serves to reinforce “reductive and essentialist thinking. While the scientific world has moved on, its popular appeal remains”. [4]This is to say that whilst many scientists no longer operate with this simple model, newer ideas have not been widely circulated. “Biologists may have been building a more nuanced view of sex, but society has yet to catch up”[5].

Also according to the latest scientific thinking there are extremely few sexual characteristics solely controlled by the presence or absence of the Y chromosome which contains very few genes. There are plenty of sexual characteristics controlled by genes found on other chromosomes, and the “sex chromosomes” also carry genes that have nothing to do with sex! Although no-one yet seems to have thrown out the pleasing little karyotype diagram, despite the fact that many variants on XX and XY are known to exist[6], it is widely recognized by the medical establishment, that the role of the chromosomes as sole movers in the process of determining sex has been woefully exaggerated. “Sex chromosomes may say one thing but gonads’ ovaries and testes) or sexual anatomy may say another” – these kinds of conditions are known as intersex or differences/disorders of sex development (DSDs) thought to be present in as many as 1.7% of the population.[7]


[1] Karyotype: the number and appearance of chromosomes in the nucleus of a cell http://www.dictionary.com/browse/karyotype

[2] Karyotype: the number and appearance of chromosomes in the nucleus of a cell http://www.dictionary.com/browse/karyotype

[3] See Bainbridge, David(2015) Curvology: the origins and power of the female body shape Overlook Press New York, NY page 28

[4]  Steadman, Ian  Sex isn’t Chromosomes: the story of a century of misconceptions about X & Y in the New Statesman February 2015 http://www.newstatesman.com

[5] Ainsworth, Claire ( 2015) Sex Redefined- the idea of two sexes is simplistic. Biologists now think there is a wider spectrum than that Nature/Nes Feature 18 Februray 2015

[6] Ibid Footnote 17 David Bainbridge mentions for example X,XXY,XXX,XYY,XXYY but still sees the presence or absence of Y as critical in determining sex (page 28)

[7] See Ainsworth cited above at page 2.A DSD known as Complete Androgen Insensitivity Syndrome (CAIS) results in people with a Y chromosome and internal testes and external female genitalia.A DSD called Congenital Adrenal Hyperplasia causes the body to produce excessive sex hormones resulting in ambiguous genitalia. Also https://www.intersexequality.com/how-common-is-intersex-in-humans/

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