Category Archives: Evolution

Every now and then I’ll read some twaddle about how humanity will soon over-populate the Earth, increase mass species extinctions, use up all available resources, etc., etc. Such babble ignores the worldwide decline in fertility rates since 1980 that ought to make people worry more in the other direction.

“Ecologists calculate that human populations require a fertility rate of 2.1 births per female to offset deaths,” writes ecologist Jim Steele. “A fertility rate below 2.1 causes the population to decline, while a higher fertility rate causes population to grow. In the 1950s, the decade of Baby Boomers, the USA had a fertility rate that averaged 3.7.

“By 1980 the rate dropped to 1.8. Now due largely to immigration, a slightly higher fertility rate stands at 2.0. Worldwide fertility rates similarly dropped from 2.67 in 1950 to 2.02 in 2000. These lower rates suggest the global human population will soon plateau and then decline. Thus decreasing population pressures will not cause an accelerating extinction rate. These decreasing fertility rates should be a cause for optimism.”

Unless, of course, you worry about civilization collapsing from too few new people coming along to sustain it. But maybe there’s a new trend in the opposite direction the demographers haven’t noticed yet. One of the adult beginner violinists I encountered at the orchestra workshop a few weeks ago was a young, Anglo woman who said that since her youngest finally had been weaned, she was taking the opportunity to be something other than a baby machine.

She has five children. You don’t look old enough to have five children, I said. Oh, I’m old, she replied, believe me, I’m old. She said the five were an accident, since two of them were twins. She and her husband had only planned on four.

Four. In an age when one or none is the rule among American Anglos. Maybe she and her husband are an aberration. Or maybe they’re a sign of an impending return to the 3.7 of the 1950s.

Via Watts Up With That.