Two Isreali scientists from Weizmann Institute of Science, Department of Molecular Genetics; Dr. Moran Gershoni and Prof. Shmuel Pietrokovski have found that there exist more than 1000 different genes in Males and Females; more than what is ever perceived.
Sexual dimorphism (two different forms, that differ in one or more characteristics), as they have mentioned in their research, is because of sex differential expression of genes. This differential expression of genes can impact human evolution by differential selection on mutation with dissimilar effects on the two sexes.” Also, these differences in gene expressions can lead to differential disease susceptibilities.
Their research published on BMC Biology in early 2017 has also shown more than 8100 Sex-Differential Expressions in male and female genes.
To understand Sex Differential Expression (SDE) in human males and females, we need to understand that almost all genes that are common to both sexes Gershoni and Pietrokovski have analyzed 45 common tissues in human males and females. But the same genes are expressed in a different manner in the two sexes. For example, both male and female human beings carry genes associated with lactation. However, after childbirth, it’s only human females who lactate and not the human males. This is how similar genetic systems are expressed in a different manner in the sexes.
These scientists have found that this sexual dimorphism (differential expressions in genes) has been demonstrated in diverse human traits, such as –
i. Brain Anatomy and Development
iii. Mortality, Longevity and Morbidity
iv. Distribution and Metabolism of Fat Biogenesis
v. Physical Performance Capabilities
vi. Pain Response etc.
Their paper also referred to another study about B-lymphocytes (a type of white blood cells in humans) also have sex-differential expressions. That means response to several diseases by males and females is different.
Gershoni and Pietrokovski also found 8100+ Sex-Differential Expressions (SDEs) in the genes existing in the tissues common to both sexes. Here’s a snapshot.
They have classified each gene found in 45 tissues common to both sexes according to RNA sequencing method and noted the expression of the genes. Then they have assigned an SDE score to each gene in those tissues. From that table, presented in the study as Table S1, shows 8100+ SDEs in different genes. (Note, the same gene may be present in multiple tissues and express differently).
In an exclusive conversation with The Male Factor, Professor Moran Gershoni clarified that the male and female SDEs were found by a method of statistical hypothesis testing where the null hypothesis was ‘there were no differences between the populations”. He also mentioned that ‘most of these differences stem from the differential use of genes carried by men and women’. To a question whether evolution is considered as an important factor in Sex Differential Expressions (SDEs) of males and females, Dr. Gershoni clarified that human evolution should at least in part be thought as co-evolution between males and females.
The determination of one’s gender is complex. It depends on many factors including genes, hormones, psychology etc. Feminists say, both sexes (biological identity, determined by X, Y chromosomes and gender organs) are identical and god had not created them differently. But, if we look at the gene expressions, we find our genes are differentially expressed (especially in same ethnic groups) which is also a factor of our ethnicity and evolution. Human evolution, as expressed by many biologists including Dr. Moran Gershoni, plays an important role in creating differences in males and females. This shows the theory of ‘Survival of the Fittest’ worked more in distinguishing between human sexes than patriarchal oppression.
I thank Dr. Moran Gershoni for clarifying some critical technical questions regarding this research.