NOT Exponential, just Excessive - Human Population
I’ve heard so many people knowingly talk about how the Human Population growth is exponential and how there are way too many of us. I just want to finally correct this long standing assumption of exponential growth.
The Human Population is NOT growing exponentially.
In population mathematics, growth rate is measured by the formula b-d=r. The rate is r. A population can only if r is constant. You could calculate teh doubling time of the population, but you find that the population doesn’t really follow a specific doubling pattern because r isn’t constant.
In fact, in recent years, r seems to be finally declining, although it is still positive.
If you look at the graph of human population, it sure looks like an exponential graph, but the highest growth rate occured between 1965 and 1995.
This doesn’t mean that the world isn’t overpopulated, it just means that the phrase is incorrect.
Kallen is currently pursuing a Bachelor's degree in Biology and Journalism at the University of Oregon and, of course, writing a blog.
Samper said,
April 3, 2008 @ 9:41 am
Totally. Most biologist and bio-mathematicians that I’ve talked to seem to factor the Logistic model for showing human growth. This model starts out looking like its going to be exponential but as time goes on and on the graph starts to petter out and when a population reaches the carrying capacity of its environment, it will flatten out.
http://en.wikipedia.org/wiki/Logistic_regression
Jyvyn said,
April 3, 2008 @ 7:40 pm
Back when it was common to have 20 children in the 1600 and 1700s, even with high mortality rates of mothers giving birth and shorter lifespans, since we are no longer having 20 children, the rate is very much unlikely exponential.
As Samper said, there will be a carrying capacity of the earth, limiting exponential growth, and we’ll likely see logistic (and hopefully not gaussian) growth.