Should Lawrence summers apologize?

On Friday, January 14, 2005, Harvard President Dr. Lawrence Summers suggested that “innate differences” between men and women might be one reason fewer women succeed in science and math careers. In addition, Summers questioned how much of a role discrimination plays in the scarcity of female professors in science and engineering at elite universities. Summers' remarks on women draw fire, and then he had to write a letter to apologize hypocritically “I deeply regret the impact of my comments and apologize for not having weighed them more carefully.”, and at the end of the letter he wrote some high-sounding words to praise women’s contribution in society and sciences.

    Should Lawrence Summers apologize? No, I don’t think so, because what he said is true, and he was just the boy who pointed out the emperor has no clothes on. In fact, as a woman, from my self-esteem, I do not want to admit, but I have to admit, in general, men indeed do better than women in math and science. As female, if you are angry because of  what Lawrence said, that is completely “weak country mentality”. There is no need to be angry due to a sentence. First of all, we have to admit that, in many ways, male performance is better than female, if we don’t have the bearing to accept this fact, we will never be able to make any progress in future. Secondly, we must look for the reasons why women do worse than men, what cause the difference? Finally, under the premise that the gene can not be changed, what can we learn from men and how can we improve our capacity?

   I don’t know what exactly the Lawrence said "innate differences" mean. if he meant that there are some special talent only in Y chromosome, but not in X chromosome, I can only say that Lawrence is really good student of “penis envy" of Freud, and he so overestimated the Y chromosome. Humans have 23 pairs of chromosomes, each pair has two homologous chromosomes, one is from mother, the other is from father. On homologous chromosomes, there are so many alleles which control the same trait, but some are dominant genes, and some are invisible genes, and X and Y are just a pair of homologous chromosomes. I guess the only difference is Y nearly has all dominant genes, in comparison of X chromosome, although males have both X and Y chromosomes, but their external appearance only determined by the genes on Y.

   I don't deny that men really can take advantage of the Y chromosome to synthesize some special proteins, hormone or other substances which women really don’t have, and males and female also can take the same substances from X chromosome they both have. We have to admit this, but don’t overestimate the Y chromosome, to any sexual organs on male controlled by the Y chromosome, there must be the homologous organs controlled by the X chromosome to respond on female. In fact, with the decryption of human gene sequence, we already start to reveal the mystery slowly.

Figure 1 is Genital Development Before Birth

Fig.1  Genital Development Before Birth

Figure 2 is Development of the external genitalia: Indifferent ( A and B ); Male external genitalia ( C and E ); and Female external genitalia ( D and F ). Gray's Anatomy (1918) figure 1119 (Drawn from the Ecker-Ziegler models).

Fig. 2  Development of the external genitalia

Fig.1 and Fig. 2 are previous theoretical studies, the followings are real pictures around ourselves.

    Apparently, we can see that there is a raphe both on glans and foreskin. Use little logical thought, we can conclude that, in the process of development of penis, penis wrapped to backward, and folded the urethra into penis, and the original separated labia majora get fusion into scrotum. In the process of development of clitoris, clitoris shaft, urethra, vagina and labia didn’t get fusion, so there is no raphe on clitoris.

    First start common development, and then differentiation. Fact, in embryo research, people have admitted that the genital tubercle develops into the phallus, the first rudiment of the penis or clitoris. I am really curious why Freud and Dr. Ernest Grafenberg still think that women should and must get orgasm through vagina, regardless Gray's Anatomy had showed up very clearly in 1918. I have to question their motives. Did they believe that men also can use other organs or glands to collect pleasure for orgasm, except penis? You must certainly laugh at me, if I tell you that high nose on West people is used to breathe, but flat nose on Asians is used to eat. Penis and clitoris shaft, different appearance, but the same functionality.

    I admit that male perform more excellent than female in many area, such as art, music, sports, creative pursuits, science, politics and so on, not only in math and science Lawrene mentioned. But why? Objectively speaking, I really don't think Y chromosome is the key, not because I am a female and I have penis envy. If Lawrence was right "innate differences” really exist, as the result is every man should be smarter than every woman., but not that way. Undoubtedly, a lot of people exaggerate the differences between men and women, like lawrence, but we should see essence through the appearance. But why in general men are more outstanding than women in many ways? I think sex is the key, precisely orgasm is the key. Orgasm really matters a lot. If you ask me what is you favorite activity? I will answer orgasm. It not only can make me release, but also can give me logic and inspiration, maybe that is why I am different from other women. I believe that, one day when women can get out of the trap of reproduction to find the true themselves, women will be the same excellent in every area, maybe more excellent.

Evolutions of male and female indeed developed in different ways.

Recently, I found old interesting news from internet. Evolutionary biologists have long believed that the mammalian Y chromosome is essentially stagnant, having lost most of its genes hundreds of millions of years ago. But new research from MIT's Whitehead Institute, published in this week's issue of Nature, overturns that theory. The research team, led by Whitehead Institute director and MIT biology professor David Page, showed that the Y chromosome is actually evolving rapidly and continuously remaking itself. The results overturned the expectation that the chimp and human Y chromosomes would be highly similar. Instead, they differ remarkably in their structure and gene content. The chimp Y, for example, has lost one third to one half of the human Y chromosome genes--a significant change in a relatively short period of time. Page points out that this is not all about gene decay or loss. He likens the Y chromosome changes to a home undergoing continual renovation.

I agree with Page on his result that Y chromosomes indeed evolved faster than expected, but I don’t agree the explanation they gave. The followings are my questions.

1, "The region of the Y that is evolving the fastest is the part that plays a role in sperm production," say Jennifer Hughes, first author on the Nature paper and a postdoctoral researcher in Whitehead Institute Director David Page's lab. 

I don’t agree with Jennifer on this point. Frankly speaking, I don’t think the Y chromosome plays any role directly in sperm production, because in the end of MeiosisⅠ, the X chromosome and the Y chromosome have already been divided into different cells, and in simple words, the MeiosisⅡ is just a normal Mitosis. At the end of MeiosisⅡ, male produce four spermatids, two have X chromosome, other two have Y chromosome, and formation of sperm is just a deformation based on meiosis finished.

  

 

If Jennifer was right that some region of the Y plays a role in sperm production, the sperm which contains X never exist, because they don’t Y chromosome at all, but the fact is that the spermatids, whatever it contains X or Y, always can turn into sperm cells.

About Azoospermia, in general, it can be classified into two forms:

Obstructive Azoospermia: In this situation, sperm are produced but not ejaculated. The main cause is a physical obstruction (obstructive azoospermia) of the posttesticular genital tracts. The most common reason is a vasectomy done to induce contraceptive sterility.

Non-obstructive Azoospermia: it can be divided into two situations.

Pretesticular azoospermia: it is characterized by inadequate stimulation of otherwise normal testicles and genital tract. Typically, follicle-stimulating hormone (FSH) levels are low (hypogonadotropic) commensurate with inadequate stimulation of the testes to produce sperm. In simple words, the reason why a little boy don't have sperm is that there is not enough sex hormones to make him produce a sperm.

Testicular azoospermia: In this situation the testes are abnormal, atrophic, or absent, and sperm production severely disturbed to absent. In simple words, This may be due to chromosomal abnormalities, such as Klinefelter syndrome (karyotype 47XXY), or microdeletions of the Y chromosome, which is the loss of genetic material involved in spermatogenesis.

About Klinefelter syndrome (karyotype 47XXY) or XYY, XXXYY, XXXY, XXXXY gene types, due to the odd chromosomes, spermatocytes have disorder in Synapsis MeiosisⅠ, so they can’t produce a sperm.

About Y chromosome infertility, some research illustrates that it is usually caused by deletions of genetic material in regions of the Y chromosome called azoospermia factor (AZF) A, B, or C. Genes in these regions are believed to provide instructions for making proteins involved in sperm cell development, although the specific functions of these proteins are not well understood. Deletions in the AZF regions may affect several genes. The missing genetic material likely prevents production of a number of proteins needed for normal sperm cell development, resulting in Y chromosome infertility. I agree with this explanation very much, as everyone knows, genes not only control the synthesis of protein, but also steroid substances and enzymes. The Y chromosome is still there, but lack of some genes result lack of some special protein or steroid or enzymes, then result azoospermia.

In summary, the mechanism of sperm deformation is not completely understood so far, but I really don’t think Y directly plays a role in sperm production. I think Jennifer Hughes overestimated the Y chromosome too much, maybe she fell into the trap of "penis envy” of Freud.

If conditions permit, we can change the positions between spermatocyte and oocyte, and check whether spermatocyte can still produce into sperm and oocyte can still produce into egg cell and polar bodies or not. I guess it is impossible, and Thai Shemale is the biggest evidence for that. They can’t produce sperm, because they were injected estrogen since very little boys, but Y chromosomes are still in their genes. This can illustrate that very well chromosome is not directly involved in sperm formation.

2, The researchers suspect several factors are at play in the divergent evolution of human and chimp Y chromosomes, including differences in mating behaviors. Because a female chimpanzee may mate with many male chimpanzees around the same time, any genes on the Y chromosome that lead to enhanced sperm production offer a distinct competitive advantage. If a Y chromosome with genes for enhanced sperm production also carries mutations that alter or eliminate a gene not related to sperm production, those less advantageous mutations also get passed on, resulting in a Y chromosome with far fewer genes than the human Y.

The reason why I don’t agree with them on this point is that I don’t deny that positive selection is driving rapid evolution, but apparently, human evolution is much more far than chimps, in other words many many years ago, human also have the group sex as same as chimps that a female human may mate with many male human during her estrus, but with the evolution of human beings, we get rid of the chimps mode. There must be something which drives human to evolve out of chimps. Please notice that: male chimps only have sex with female chimps during her estrus, but male human don't have sex only during female human estrus, and apparently the purpose of male chimps having sex is only for reproduction, but it doesn’t apply to male human. I think a rational thought is that we should focus on some behaviors which human have but chimps don’t have, not on some behaviors which chimps have but human don't’ have. If we go to the opposite direction, we are not going to find the truth at all. Now we don’t have to consider that why the chimp Y has lost one third to one half of the human Y chromosome genes, we have to reconsider why human has increased one half to one of the chimp Y chromosome genes. Maybe the extra genes in male human are the key why the purpose for male human having sex is not only for reproduction.

In general, I agree that Y chromosomes indeed evolve fast than other chromosomes, whatever in horizontal comparison or vertical comparison. In horizontal dimension, as a female, I have to admit that men in general are more outstanding, smart or rational than women in all areas, wherever politics, science or sports. Why is that? Because women don’t have Y. Does Y really have so magic power? Yes, it does, men have really jumped out of the trap of reproduction, but women still as tool as reproduction. In vertical dimension, male human indeed evolved much faster than male chimps, male chimps are still stuck in the trap of reproduction.