I Almost Didn't Exist

What are the chances of you or me existing at all? I'm not going to conclude by stating probabilities; it is an impossible calculation as you will see. I am more interested in how people approach this question. I will address two approaches in this post

Whether you believe in a creator or not, the discussion is pertinent. Whether you evolved from a single-celled animal or were created by an omnipotent entity, an exact copy of you would require the same level of complexity.  In other words, however, you came to be it is equally unlikely that you would be among the chosen creatures to walk on this earth.

Regardless of how you approach the question, you will come to a point where you need to calculate the number of combinations of unique genetic material that are possible and ask how likely it is that your exact combination exists. Let's start with the DNA of identical twins. They are not the same person although they have the same combination of genes at birth. Obviously, combinations of genes can't be the entire answer to the question. In addition, an unknown number of possible genetic combinations are not viable human beings. And there are a large number of factors outside genetic codes that matter. 

Nevertheless, conservative assumptions produce numbers. A postdoc in computational biology reports the probability of randomly selecting two identical viable human genes to be: 1/x where x is 1 followed by 10 million zeros. The largest number I know is googol = 10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 That's only 100 zeros (Google picked its name as a variation of this to indicate it intended to access a nearly infinite amount of information). Imagine replacing the 100 zeros with 10 million zeros! By the way, there is not even a googol of atoms in the universe by current estimates. And combinations of genes are just one step in the calculation of the chances of you being here at all.

Let's look at the question from a different angle. The average man produces over 30 trillion unique sperms in his lifetime none of which are exactly alike. Neither are two eggs exactly produced by a female alike. You are the unique result of one particular sperm and one particular egg. The probability of your parents coming up with the one and only combination to produce you is incomprehensibly small (less than 1 in 10 trillion).

Then we need to consider the same calculation for your grandparents, and their parents and so forth back through the 40,000 generations or so in human history. We get a nearly infinitesimal number: 1/x where x is 2 with nearly a million zeros following. This is a larger probability than the first approach calculating probabilities of genetic combinations but still pretty small.

But, you are here. Call it a miracle, argue that the probability of your existence equals one, or claim that your creator bypassed all the evolutionary steps and designed you in all that detail from scratch. However you look at it, you won the ultimate lottery; you're here reading this blog post sharing my bizarre musing.

I stated at the beginning of this blog post that such calculations literally are impossible. If you live your life mostly out of harm's way, you are incalculably lucky. There is no greater lottery to win. Enjoy your winnings as best you are able.