The Abraham Effect: The Future of Humanity Depends on You

(excerpt from Lenses, a collection of book-length essays, in search of a publisher)

Just as the entire Jewish people are descended from Abraham, the people who inhabit Earth a thousand years from now may all be descended from you.
You have two parents, four grandparents, eight great-grandparents. The number of your ancestors doubles with every generation. Counting backwards 1000 years, about 36 generations ago, you had about 69 billion ancestors, which is that's 2 to the power of 36. But at that time, there were only about 50 million people alive in Europe, meaning that distant cousins mated with one another.
There were people alive in Europe a thousand years ago who were the ancestors of everyone of European descent who is alive today. In other words, everyone of European descent alive today is a cousin of everyone else, and probably in multiple ways due to distant cousins marrying, often without knowing they were cousings.
Fast forward a thousand years, taking into account that people are much more mobile today than they were a thousand years ago. In the year 3000, every human being alive on Earth, if the human race survives that long, will be a descendant of people who are alive today; and if you are a parent, there's a chance that everyone alive a thousand years from now will have genes that passed through you.
That is an awesome responsibility.
Be careful. Be proud. The future humanity race depends on you.