The Better Half

In school we called these book reports, in our adult life we call it book reviews, I am trying one of these for size without using Cliffs Notes. The book that I am currently reading fell into my hands via my main-man’s mother. Her choice of books interests me, she has a good selection of subject matters. This particular book is titled The Better Half: On the Genetic Superiority of Women written by Sharon Moalem, MD, PhD and probably some more letters to follow (the man has credentials, bonafide).

The main concept of the book is that humans have 23 pairs of chromosomes (46 total). Each one of our chromosomes is full of genes. Some of the genes are active, some are not, some we studied and understand their function and others are still an enigma but whatever this master code is, genes describe everything about us and many things that can potentially happen to us and how our organism would deal with such things. The difference between a biological man and a biological woman is in one pair of chromosomes. A woman receives an X chromosome from her mother and an X chromosome from her father resulting in an XX pair. A man receives an X chromosome from his mother and a Y chromosome from his father resulting in an XY pair (there are uncommon genetic exceptions to this rule). As a result, women have a redundant system with the two Xes, if a certain gene on one of the Xes is faulty and there is a good one on the other X then the good one can work as an active primary. Men on the other hand having only one X do not have such a benefit resulting in various conditions which are more common in the male population than in the female one. Some more common conditions in males are color-blindness, hemophilia, certain muscular dystrophy, fragile X syndrome and numerous others.

But what about the Y chromosome that men posses but women do not? Clearly there is sperm production and testosterone production which leads to physical differences such as size and strength. Men do not have redundancy in the Y chromosome so any mutation or deficiency is something that the individual is stuck with. I presume women not having the Y chromosome simply do not miss it. As a matter of fact, it is nice not to worry about hairy ears, webbed toes or porcupine skin, all traits carried by genes associated with the Y chromosome. Never the less, I ask is there something of meaningful value that women could miss because of the lack of the Y chromosome, something not as obvious as size, strength and extra hair everywhere? I emailed this question to Dr. Moalem and am awaiting his answer. As a woman it is super cool to read a book titled: On the Genetic Superiority of Women, but I also live in the real world where as a woman is it difficult to feel superior to our men counterparts especially when it comes to business, money and power.

Additional thoughts regarding sex chromosomes:

What about those who are XXY (a random genetic event, not hereditary) – also called Klinefelter syndrome? A genetic condition where a boy is born with an extra X chromosome. I would think that this provides a male with the X redundancy making him less prone to X-related medical conditions so a good thing but in reality, these males have to deal with various not so desirable issues.

If there is an XXY what about XYY? – also called Jacob’s syndrome. Once again one might think that having a redundant pair of a Y chromosome should be a positive thing but in reality, it seems not to have much effect on the lives of individuals affected with only “minor” symptoms documented. I guess there are no instances of XYY with webbed feet, hairy ears or porcupine skin? Maybe a geneticist can answer this question.

One might think that nature should have created 24 pairs of chromosomes where each of us would inherit a couple Xes and a couple Ys and then by some other method would select our sex. In this case we would all have a benefit of genetic redundancy. A quick google search shows that there indeed exists an XXYY syndrome and since there is a word “syndrome” in the description it must not be an ultimate solution but some genetic condition. Humans who are XXYY indeed have 48 chromosomes and are classified as genotypical male because it takes at least one Y to be biologically classified as such. What strikes me in all cases of extra sex chromosomes is that individuals with the extra genetic material tend to be taller but also mentally slower so while on height more is more, mentally more is less – hmm?

Our adventure into sex genetics would not be complete if we don’t ask a question what if an individual has too few sex chromosomes, meaning one instead of two? Turner syndrome, afflicting strictly women, appears when an individual has only one X chromosome (the other one might be missing or partially missing).

Lastly – I have not ran across a reference to a living example of a human with only one Y chromosome or no sex chromosomes, I presume such instances result in a biological expulsion of an embryo.

Post Script regarding sex chromosomes: This was not intended as a Wikipedia entry into sex-chromosome genetics but it ended up as such. 30 years ago, it would take hours of library searches to get to this level of information (which might have not existed at all). Today, a little time on the Internet and such a wealth of info!

As I kept reading the book getting further into the chapters, I appreciate concepts related to how testing of drugs is performed and how FDA guides but does not mandate in pre-clinical tests that both sexes of animals be used. As a result, less testing is performed on females. I also learned that for a researcher to get their hands on female mice is much more difficult and more costly and requires a special order as opposed to getting male mice. Female mice have stronger immune systems which complicate studies of drugs intended to fix diseases (it is easier to get results from subjects with weaker immune systems.) Human males and females metabolize drugs differently and for numerous reasons might require either different doses or completely different drugs; with current testing methods these differences are not always acknowledged. What strikes me about this information is my prior knowledge about the HeLa cell which in 1950s was taken without consent from a female cancer patient. This cell has a strange gift of never dying and continually reproducing itself. I read that most research on human cells is done on female HeLa cells. But there must be a meaningful difference between cell research and full animal organism research. Yet somehow, HeLa cells should play into the story of this book, too bad that it was not mentioned.

While I truly enjoyed the book and would definitely recommend it to those of you who are science minded, I do not like the subtitle: On the genetic Superiority of Women and I find it ironic that a person who appears to be of a Jewish heritage, Sharon Moalem, would publish a work that in any way proclaims one type of human as superior to another human – Hmm.

Get the book, borrow it from your local library, read it – it is a good read and will build a significant awareness of the subject matter.