Post a random fact
Originally Posted by magician,May 16 2008, 11:32 AM
I'm pretty sure this isn't true.
Without getting into a big mathmatical disscussion. How many thousands or millions of people do you think inhabited the planet say even.... 2000 years ago?
Go back farther ...go all the way back to the ICE age or whenever you think the "dawn" of man would have been.
the human population on this planet only realy started blossom quickly in the past 2000 years or so...
[QUOTE]by Carl Haub
"How Many People Have Ever Lived on Earth?" is the most requested Population Today article. It first appeared in February 1995.
(Population Today, November/December 2002) The question of how many people have ever lived on Earth is a perennial one among information calls to PRB. One reason the question keeps coming up is that somewhere, at some time back in the 1970s, a now-forgotten writer made the statement that 75 percent of the people who had ever been born were alive at that moment.
This factoid has had a long shelf life, even though a bit of reflection would show how unlikely it is. For this "estimate" to be true would mean either that births in the 20th century far, far outnumbered those in the past or that there were an extraordinary number of extremely old people living in the 1970s.
If this estimate were true, it would indeed make an impressive case for the rapid pace of population growth in this century. But if we judge the idea that three-fourths of people who ever lived are alive today to be a ridiculous statement, have demographers come up with a better estimate? What might be a reasonable estimate of the actual percentage?
Any such exercise can be only a highly speculative enterprise, to be undertaken with far less seriousness than most demographic inquiries. Nonetheless, it is a somewhat intriguing idea that can be approached on at least a semi-scientific basis.
And semi-scientific it must be, because there are, of course, absolutely no demographic data available for 99 percent of the span of the human stay on Earth. Still, with some speculation concerning prehistoric populations, we can at least approach a guesstimate of this elusive number.
Prehistory and History
Any estimate of the total number of people who have ever been born will depend basically on two factors: (1) the length of time humans are thought to have been on Earth and (2) the average size of the human population at different periods.
Fixing a time when the human race actually came into existence is not a straightforward matter. Various ancestors of Homo sapiens seem to have appeared at least as early as 700,000 B.C. Hominids walked the Earth as early as several million years ago. According to the United Nations' Determinants and Consequences of Population Trends, modern Homo sapiens may have appeared about 50,000 B.C. This long period of 50,000 years holds the key to the question of how many people have ever been born.
At the dawn of agriculture, about 8000 B.C., the population of the world was somewhere on the order of 5 million. (Very rough figures are given in the table; these are averages of an estimate of ranges given by the United Nations and other sources.) The slow growth of population over the 8,000-year period, from an estimated 5 million to 300 million in 1 A.D., results in a very low growth rate








