Dear Readers and Friends: August edition out , Aug 17 2018

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Sex and gender determination not unique in Africans

Okot Nyormoi
Okot Nyormoi is is a peace activist and is Professor of Biology at North Carolina Central University

 

 

In the last decade or so, the debate about homosexuality has been raging in Africa. The idea of homosexuality conjures up all kinds of images in the minds of many Africans. To arouse negative sentiments against homosexuals, special words such as unnatural, sinful, unproductive people, sexual mercenaries, prostitutes and un-African are carefully employed to describe them. The debate has since morphed into anti-homosexuality laws in Nigeria and Uganda, allegedly based on scientific, cultural and religious grounds. Such laws have left many Africans cheering almost in the same way Romans used to cheer gladiators engaged in mortal combat at the coliseum. They also left many people, particularly in Western countries, gasping in disbelief. Between these two extremes are people who are simply confused about the validity of the scientific basis.

To address the question of why both sides of the debate are frothing at the mouth, it will be helpful to first try to understand the basics of the biology of gender beyond isolated buzz words carefully crafted to extract maximum positive publicity on the proponent side and negative on the opponent side. Such knowledge should enable a better understanding of the issue.

Evidence shows that the biology of sex, gender or gender identity of living things is amazingly complex. Some organisms lack sex or gender whereas others do. The basic purpose of sex is to generate diversity among living things, necessary for survival under adverse conditions. Yet most simple unicellular organisms like bacteria have no sex. Instead, they use rapid multiplication to increase the probability of variation. Resistance to antibiotics is an example of one of such variation.

In contrast, complex living things usually have sex and gender, but with exquisite variations. If one is befuddled by the notion of homosexuality, think of the whiptail lizards of Mexico which exist exclusively as females and they reproduce themselves wonderfully well without males. Some of them have been observed to mount each other, but it is not clear whether that is an act of homosexuality.

Another type of sexual variation is found in both plants as well as worms in which individuals have both sex organs. In corn or maize, kernels develop from the egg and pollen is equivalent to sperms. They do both self- and cross-pollination. Similarly, earthworm contains both sex organs. However, they mate with other individuals. In contrast, those who grow papaya well know that male trees do not produce fruits because papaya plants exist strictly as male or female and they practice heterosexual reproduction. Males produce pollen used to fertilize eggs produced by females. Finally, most animals, birds, fish and reptiles develop into distinct males or females.

If variation in sex and gender types does not present enough complexity, think of the variation in the systems of sex determination. If you were an alligator or turtle, your sex would be determined merely by the temperature at which you are incubated while developing in the egg. If you were a type of snail, you would all be born male until later on when some of you become females. In some fish, gender can be switched depending on social status. In their community, the dominant individual is the female whereas in another type of fish the opposite is true. How about physical contact between a baby marine worm and a female worm which seals its fate as a male?

Although we are accustomed to associating bacterial infection with diseases, in the world of some insects, gender determination depends on infection by certain bacteria. In others, sex determination may depend on diet during development or what role individuals play in insects with cast systems. Sometimes the sex of individuals can be switched depending on the need of the social colony.

In mammals, the male trait is determined by the presence of the Y chromosome. However, that fact is now being questioned because evidence suggests that the X chromosome may after all play a necessary role in sex determination. For example an embryo with just one or more Y sex chromosomes is non-viable.

These are by no means the only systems of sex determination and there is still a lot more to be learned about human sexual determination and preferences. Presently no single gene is known to be responsible for homosexual or heterosexual preferences. Any claim that gender determination is simple and written in stone is simply false.

Since the discovery of the science of heredity by the Austrian monk, Gregor Mendel, the inheritance of traits is now known to be influenced by the exquisitely complex and dynamic interaction between genes, hormones and environment. Such interactions include the mixing and reshuffling of existing traits and induction of changes in the hereditary material. Induced changes may or may not show up as observable traits. Those which are manifested as traits may have good, bad or no consequence at all. That is why other than identical twins, no two individuals are alike.

Sex and gender specification require more than just inheriting chromosomes; an appropriate environment is necessary for the process to occur normally. Apart from changes in the hereditary material, physical and chemical factors in the environment may affect the functions of traits specified by genes. Such changes are usually not transmitted from generation to generation. However, scientists are more and more convinced that functions of some genes can be altered without changing the hereditary material and that the alterations can be transmitted through several generations, a phenomenon known as epigenetics.

Regardless of whether a trait is inherited genetically or epigenetically, occasionally, the process goes wrong, thus producing rare and unusual chemical, physical and behavioral traits such as sickle cell anemia, Down syndrome, cleft pallet, deformed limbs etc. Evidence also shows that it is within these complex patterns of inheritance that mistakes involving sex and gender determination occur.

In humans, normal females are determined by XX sex chromosomes whereas males have XY chromosomes. If the sex chromosomes do not divide and separate properly during the formation of eggs and sperms, they end up making babies with unusual chromosome numbers. Females with Turner’s syndrome have XO sex chromosome. Males with Kleinfelter’s syndrome have XYY chromosomes. There are many others.

Besides abnormalities in chromosome numbers, individuals may also show unusual behavior. It is not uncommon for parents to be concerned over children who are physically of one gender but behave as if they are of the opposite sex. In the English language such girls are described as tomboys and girlyboys or sissies. Apparently such trans-sexual behavior occurs naturally and often in spite of the objection of the parents. Although parents and society may succeed in suppressing the external display of such behavior, it is not clear what such people think or feel on the inside about their gender or sexual identity.

Given this brief background on the science of heredity and the biology of sex, gender and sexual identity determination, it is pertinent to ask whether Africans, like other humans, are subject to the same principles of heredity and sexual determination. The answer is yes in principle and fact. Otherwise, to say no would be to assert that Africans have a unique biological system distinct from all other living organisms in general and modern humans in particular. There is simply no evidence for that.