How many people have lived on earth since the dawn of time?

Dear Cecil: How many people have lived on the earth since the beginning of time? The reason I’m asking is I want to know if there’s going to be enough room in heaven for all those souls. Listener, Roy Leonard show, WGN radio, Chicago

Cecil replies:

Boy, for a minute there I thought you were going to say something silly.

Estimates of the total roster of humankind rely heavily on guesswork, a state of affairs not entirely unknown to us here at the Straight Dope, and accordingly the numbers vary widely. Demographers have come up with estimates ranging between 69 billion and 110 billion humans. That gives us a spread of 41 billion, a pretty formidable margin of error.

Still, these numbers should put to rest the line of baloney put out years ago by the zero-population-growth alarmists, namely that the majority of humans who have ever lived is alive today. That’s flat wrong no matter what your assumptions.

For example, creationists, who believe it all started with Adam and Eve around 6,000 years ago and that a flood in 2700 B.C. killed off everybody except Noah and his relatives, say the world population to date is 51 billion. Some may feel the creationist figure is entirely too close to the “real” figures for comfort. Maybe, you’re thinking, we should abandon the pretense of science and address future demographic inquiries directly to God.

Well, I told you this involved a lot of guesswork. The main problem is that we have only a vague idea of the birth rate and average lifespan in ages past. Another complication, among scientists at least, is that it’s impossible to say precisely when our primate ancestors became human. Many researchers have arbitrarily settled on one million years ago, even though our own subset of the genus Homo, H. sapiens sapiens, didn’t emerge until around 40,000 years ago. If the paleolithic crowd (1 million years to 25,000 years ago) strikes you as too crude for admission to the communion of saints, subtract 36 billion or so from the figures above.

But before we start whittling down the eligibility list, I just have one question, my friend. What makes you think you have to worry about how crowded it is in heaven?

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.