Is homosexuality a mutation?? You may have got this question before. But have you got the answer for this, or have you ever tried to get it.
Well, we have a brief explanation over here.
Let me start with the question, What is homosexuality?
In common words, homosexuality is the attraction among the same sex. It is a common trait found in the population, ranging upto 10% of the whole.
It seems as if it runs in the families as hereditary trait. It’s not because of the change in a complete chromosome or DNA. It is only a compound that sits on the DNA and controls it.
Till today it is certainly acceptable that homosexuality is not just a single mutation. As per the studies, homosexuality may be due to heredity, but the cause also includes developmental component.
When we come to the discussion of genes and traits, one thing we must know is, one single gene can affect one or even more traits and one single trait can be affected by one or more genes. Similarly, the carrier of homosexuality is determined by a number of genes and each of them contributes to the carrier being homosexuality.
So how do the genes contribute?
It’s through the allele. If someone inherits many of the homosexuality allele then the probability of being homosexuality is high. If they inherit the heterosexual allele of all, the probability is low.
As we have already mentioned before heredity alone is not responsible for homosexuality. A study of male twins revealed that it is the epigenetic effects that influence on sexual orientation.
Epigenetic effects are the chemical modifications of the human genome that doesn’t change the DNA sequence, but only alter the gene activity. The study says, the identical twin of a gay man has only 20% to 50% chance of being a gay, despite of sharing the same genome.
This clearly explains that there are two chances for the homosexuality in human.
First is through the inheritance. If someone inherits most of or all the homosexual alleles from their parents, he can be homosexual.
Second is due to epigenetic effect. After birth, during the process of development, chromosomes are subjected to chemical changes that don’t change the nucleotide sequence but can turn genes on and off. That is, they can control the genes and make them active or inactive. They are the compound that sit on the DNA and controls the activeness of gene at certain time. These epi-marks are related to sensitivity to hormones in the womb.
They may help to buffer a female foetus from high levels of testosterone by supressing receptors that respond to testosterone or to buffer a male foetus from low levels of testosterone by upregulating receptors that bind to the hormone.
Normally these “epi-marks” are erased when the eggs and sperms are produced. So that it should not be carried to the offspring and the foetus can start with the blank slate. Sometimes, these epi-marks remain unerased and are passed on to the next generation.
Such unerased marks might lead to homosexuality when they are passed on from mother to son or from father to daughter. These inherited epi-marks influence a foetus’s sensitivity to testosterone in the womb might “masculinize” the brains of girls and “feminize” those of boys leading to same sex attraction. That’s what we call Homosexualilty.