The Almost Zero Probability of Your Existence and Yet, Here You Are!
If we could magically jump back to a thousand years ago, what are the odds that any particular person alive today would be lucky enough to achieve existence for a second time? It is almost zero. Which of these would be more likely, a person winning both the Power Ball lottery and the Megamillions Lottery, 10 times in a row, or that same modern-day person achieving existence for a second time? For a person to win both the Power Ball lottery and the Megamillion lottery together is a 1 in 75 quadrillion chance. But could you imagine winning them both, 10 times in a row? My hunch is that you are more likely to win those two lotteries, ten times in a row than you are to come into existence again if we set time back to 1000 years ago. Here’s why.
A thousand years is about 40 generations. So let’s go back to the time of your great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great grandfather (or 37xgreat grandfather). Let’s call him Jake. In order for you to exist, Jake will have to survive long enough to meet your 37 x great grandmother, Sarah. Before they meet, there will be all sorts of events that have the potential of ending your chance of existence. Jake could get killed in a war or be eaten by a predator or die in a plague or just meet another woman or fall asleep and miss the dance that Sarah attended, or leave the dance five minutes before Sarah got to the dance. But he met Sarah, and three years later on the night their only son, Caleb, was conceived they almost had a falling out. Jake was about to tell Sarah that he wanted to buy another horse, which for some reason would have upset Sarah just enough to put her in a different mood. But Jake waited one extra day to tell her and so that night 300 million sperm from Jake set out to find one of Sarah’s eggs. The sperm that was going to form Caleb got a slow start, tens of thousands of the other sperm were further ahead for a while, but due to temperature, viscosity, acidity, and many other factors, the Caleb sperm finished strong and won the race. Whew, that was a close one. Because if that had not happened, then your chances of existence would have become zero. Not small. Zero. Congratulations, you got through one of an incredibly large number of hoops toward existence.
Let’s consider another of the hoops that had to happen for you to exist. In 1861, James Doe was killed in the American Civil War by “friendly fire”. It was a fluke event that happened very near the end of the Battle of Bull Run. Very unfortunate for James Doe (and his potential offspring), but very fortunate for Max Smith who is your great, great, great, great grandmother’s father. Except for a stray bullet nicking the carotid artery of James Doe, James would have met, courted, and married Eleanor Hastings. Instead, Max Smith married her seven years later. Eleanor and Max had two daughters before they had your great, great, great, great grandmother’s father. If one of those daughters was a son, they weren’t planning on having any more children. But they thought they’d give it one more chance to have a boy. On the 27th attempt, Earl was conceived. Four of those 27 attempts were near misses. That’s 27 times 300 million sperm, or 8100 million, only one of which was able to form Earl. And thank goodness for Earl and you, that it did. Too bad for Tom, Kathy, Nick, Bill, Sarah… (please fill in 8099 million names here) who never came to be. Just lucky Earl, who ironically would many times in his life feel like he was unlucky. One of those times was because he didn’t win a carnival raffle. Which made him leave the carnival early, where he bumped into your great, great, great, great grandmother’s mother and walked her home.