Inheritance Biology
Posted on February 22, 2022 • 4 minutes • 759 words
A few believe the world is a great mathematical equation where every seemingly uncertain event is calculable. A few more believe certainty is just an illusion we create to comfort ourselves. Today, let us explore how calculable you could be. Let me start by asking you if you have a hairline that is straight or V-shaped. If both your parents have a straight hairline, I’m pretty sure you too have a straight hairline. How did I know? This is the game of genetics. The colour of your skin, the length of your eyes, your height, your potency for aggression, suicide, social and test-paper performance, all of it is encoded in your genes. You can never be taller than what your genes dictate. You can never be smarter than what you were meant to be. You are in a way predestined. Let us explore this thought for a little longer.
It was in the year 1866 when an Austrian monk published his work, the scientific community knew that traits that are inherited are calculable. Thus emerged the branch of genetics. As decades passed by, we knew how genes were responsible for a trait and how they are segregated. We used genetics to improve our crop yields and, we also calculated the probability of Queen Victoria’s son having a disease called haemophilia. We started to predict the blood group of children and also certainly told that your son will have hair in his ear if you have it. Genetic counselling centres are now established to calculate the probability of your progeny having a specific disease.
The question is how does this work? Well, think of this like this. You have two genes responsible for your height. You get one from your mother and one from your father. The king gene is asking you to grow tall and a queen asking you to be short. Following the orders of the king, you would grow tall. You give your son a queen and your partner who is short also gives him a queen gene. King not being present, he obeys his queen and remains short.
Now, this is how we can calculate your traits. But the twist comes with a lot of complications. You are not tall or short. You can be anywhere between tall and short. The queen could be equally powerful as the king. There could be more than one king or queens asking you to do the same job. One king can ask you to do hundred different jobs. The major complication in the calculation arises with the number. There are more than 700 genes regulating your height and so the probability of you being short when your parents are tall is just a lucky draw to win a million dollars.
The calculations need not always be difficult. A few examples include, two parents having red hair and always having red-haired progeny. A colour-blind grandfather has 50% of his grandsons being colour blind. A man with a high risk of coronary artery disease always has his son with a high risk for the disease. But wait, I did talk about the risk of the disease and not the disease itself. Most of the time, a trait is indeed governed by genes but not completely. Environmental factors show a great effect on how good is a gene transmitted or expressed.
Up to 50% of aggressive behaviour in a person can be explained by genetics but the other 50% is influenced by factors like stress, substance abuse, diet, sleep, etc. 57%-73% of your intelligence is inherited. The rest depends on your ability to work hard. Interestingly, genetic inheritance of IQ is correlated with adulthood than childhood. If you are intelligent and your children are not, wait for them to grow. Sometimes, the inheritance pattern is so variable as in the case of BMI. Heritable estimates of weight range from 50% to 90% leaving the rest to your lifestyle. And does all of this mean that it’s just a random event that dictates why you are who you are?
As someone once told me that randomness is just a complex phenomenon to which an equation is yet to be discovered. If you plot the heights of an entire population, or the IQ, or the happiness of an individual, you get something called a bell-shaped curve. All of these traits in a bigger picture seem to be following a pattern and any deviation seen also could be ultimately calculable. You are what you are is never a mistake in the calculus of the universe.