How You Won the Genetic Lottery

Imagine walking into a room full of strangers and searching in vain for some commonality.

The people gathered have various jobs and interests; represent different age groups, races and creeds; and hail from different parts of the country.

Then you discover something astonishing. Every single person in the room has won the Powerball Lottery even though the odds against for each ticket are 292.2 million to 1.

Would this not defy credibility?

Yet you and everyone you know have already beaten far longer odds. It’s just that most of us don’t realize it.

This requires a bit of explaining…

Scientists and mathematicians have often labored to determine the odds against any of us existing – and their calculations can get pretty deep.

But author and M.D. Ali Binazir posted a sort of CliffsNotes explanation online, and I have further abstracted his work below. Here is how Binazir arrives at an admittedly rough – but mind-blowing – calculation:

1. How likely is it that your parents ever met? Assume that your parents met an average of one new person every day from age 15 to 40. That is approximately 10,000 people. If you reasonably confine the pool of possible folks they might meet to one-tenth of the world’s population 20 years ago (4 billion), that would be 400 million. Half of them, or 200 million, were the opposite sex. So the probability of your parents meeting, ever, is 10,000 divided by 200 million, or 1 in 20,000.

2. Binazir further assumes that your potential mom and dad had a 1 in 10 chance of continuing to talk after they met. The odds of that chat turning into another meeting might also be 1 in 10. The chance of that turning into a long-term relationship could be 1 in 10. And the odds of that lasting long enough to result in a child (you) may be 1 in 2. So the odds of this initial meeting turning into parenthood are 1 in 2,000. Multiply this times the 1 in 20,000 probability of your parents ever meeting to begin with, and the chance of you showing up on the scene is just 1 in 40 million.

3. But we have more math ahead. Each human sperm and egg is genetically unique. (Change either, and you would not exist.) A fertile woman produces approximately 100,000 viable eggs in her life. A man will produce about 12 trillion sperm over the course of his reproductive lifetime. (Binazir excludes a third, however, since the sperm created after your mom hit menopause wouldn’t count.) So the probability of the right sperm meeting the right egg is 1 in 400 quadrillion. (Let’s hope your calculator is an HP 12C.)

4. We also have to determine these odds for the rest of your lineage. Humans (and humanoids) have existed for roughly 3 million years. If a generation is 20 years, that’s 150,000 generations. And if the chance of living long enough to reproduce is 1 in 2 – life was far more dangerous back then – the odds of your lineage remaining unbroken are two to the 150,000th power, or 1 in 10 to the power of 45,000 – a number far too large to conceive.

5. Yet we’re still not done. Let’s get back to the right-sperm-hitting-the-right-egg sequence. This had to happen for your grandparents, your great grandparents, your great-great grandparents and so on for 150,000 generations. That means we have to raise 400 quadrillion to the 150,000th power. So the chance of you ever being born is just 1 in 10 raised to the power of 2.64 million (a number that may make your retirement account look smaller still). For comparison purposes, scientists estimate that the total number of atoms in the known universe is (a mere) 10 to the 80th power.

The Powerball Lottery? Ha! Your existence makes winning that look like a coin toss.

In Unweaving the Rainbow, Oxford biologist Richard Dawkins – and the first Simonyi Professor for the Public Understanding of Science – put it this way:

We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will, in fact, never see the light of day outnumber the sand grains of the Sahara. Certainly, those unborn ghosts include greater poets than Keats [and] scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively outnumbers the set of actual people. In the teeth of these stupefying odds, it is you and I, in our ordinariness, that are here…

You didn’t just show up against astronomical odds. You are here against hyper-cosmological odds.

Think about that – and then act and feel like the miracle you are.

Carpe Diem,

Alex