Genetics and Why We are Humans

   Why are we humans? Have you ever thought of this question? You may think we are humans because we can walk upright on two legs rather than on four legs. In this way we have two free hands so that we can carry and use tools. And you may think we are humans because we are intelligent, we have consciousness, and we can speak languages. However these are characteristics of humans not the reasons for why we are humans.

   If you have heard Charles Darwin’s “natural selection,” “the struggle of life”, and “the struggle for existence”, you may think we are humans because in our prelife, we fought with pigs, cows, cats, dogs, lions etc, we beat them, we were winner so that we are humans. However that is not true, there is no theory or evidence to support such an idea that we had ever engaged in battles with animals before our birth.

   If you are a Christian or a believer of other religions, you may think we are humans because of God’s grace. You are right if you see this question from the angle of religion. 

   However, from a scientific view, the answer to this question: why we are humans is actually very simple. We are humans because our parents are humans. 

   Why a pig is a pig? It is not because it was a loser, or because it is stupid or immoral; it is because its parents are pigs. If you plant a seed of apple, you can expect it to grow into an apple tree, develop apple flowers and produce the fruits of apple. The phenomenon that an offspring resembles its parents is called heredity. The study of heredity is called Genetics.

The next question following up is why our parents are humans then we are humans. Or how does the heredity happen? This is because our parents passed the information of humans to us. Based on that information we developed into humans. How did our parents do that? They passed the information of humans to us through sperms and ova. Every Human is developed from a single fertilized ovum. 

   A single fertilized ovum is about 0.1 millimeter and is hardly visible to naked eyes. Can you imagine how much information is needed to develop a human? But all these information is stored in the single cell.

   Then you may ask what component of the cell that carries the genetic information. That component is called DNA. DNA is a chemical compound, a large molecule in the cell. Genetic information exists in sequences of DNA.

   I don’t know how you feel when you think you are a human. But I always feel how wonderful it is and how lucky I am. We didn’t do anything to be humans! It is heredity that makes us humans. This is like a free gift. Isn’t it amazing!

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The above is one of 5-7 minute speeches I delivered in my Toastmaster Club.