Saturday, October 19, 2013
Overpopulation - Nothing To See, Move Along For Quite A While
"Natural Selection To Boost Fertility In Developed Countries
Jason Collins and Oliver Richards expect a resurgence on fertility in developed countries.
We propose that the recent rise in the fertility rate in developed countries is the beginning of a broad-based increase in fertility towards above-replacement levels. Environmental shocks that reduced fertility over the past 200 years changed the composition of fertility-related traits in the population and temporarily raised fertility heritability. As those with higher fertility are selected for, the “high-fertility” genotypes are expected to come to dominate the population, causing the fertility rate to return to its pre-shock level.This is not really new news. Delayed child-bearing and other attributes are being selected against. Natural selection sped up reproduction among French Canadians.
Africa is a continent whose demographic trends already do not fit the Panglossian projections of some commentators about how we've supposedly licked the overpopulation problem. In the next 90 years Africa's population will go up by more than a factor of 4. Quadrupling. Good bye many species of plants and wildlife.
The new statistics, based on in-depth survey data from sub-Saharan Africa, tell the story of a world poised to change drastically over the next several decades.The whole world is on course for a huge resurgence in fertility. Natural selection assures this outcome. The only way I can see to prevent it: government-mandated genetic engineering of offspring to reduce the next generation's desire to have kids. But I doubt that will happen.
Take a look at Tanzania, which is today one of the poorest countries in the world. As of 2000, it had 34 million people; California’s population was the same that year. Today, Tanzania has about 45 million people. By 2100, its population is projected to be 276 million – almost the size of the entire United States today, and by then one of the largest countries in the world.
One of the reasons I am not optimistic about the future is natural selection. Selective pressures are more powerful than our conscious minds. The part of our minds that thinks it controls the speech center is deceived into thinking it is in charge. Our conscious minds do far more rationalizing and far less rational reasoning than we think we do. I give us poor odds of getting in control of our instincts and curbing their most damaging manifestations."
This does seem a problem to which there is no humane solution. And one where exponential growth controls so that it only gets worse with time.
On the other hand so long as baseline economic growth is greater than population growth (which rarely tops 1%) it is not a Malthusian problem. Nobody is going to starve, at least not without the actions of warlords.
Even in the very long term I think population can expand enormously. I have written previously of how we could build many millions of O'Neill colonies which would mean we could support a population thousands of times Earth's current one. 700 years at 1% annual growth would not be enough to achieve that.
Where there is a problem is with differential demographic growth. Differential growth means some communities will be swamped, as the Serbs, who had lived in Kosovo for at least 1,000 years (as place names and 1,000 year old churches prove) were swamped by Albanian (not all local demographic growth but even where it was immigration part of the driver for that was high population growth in Albania). The other driver of immigration was people in poor countries wanting to move to rich ones, in the same way that water runs downhill.
This, plus the fact that poor peoples tend to have more kids, means that population growth brings down competence.
It means that failing cultures outbreed successful ones.
It means, if IQ testing around the world is of any use in finding IQ, that the future belongs to low IQ sub-Saharan Africans, rather than Parsees, Jews, Japanese or Chinese who all score above average on IQ.
Cultures which deny population controls (Amish, Catholics) or deny women the right to choose (Islam) will gain through differential growth, assuming they are able to prevent people quitting.
"Here's a gloomy idea. No population in which there is substantial equality between men and women is maintaining its numbers at the present level of technology. Only the populations in which women are substantially oppressed are growing. As more and more equality of the sexes is achieved, the birth rate of a country declines." --- John McCarthy
I would not like such cultures to supplant what we call western civilisation but the universe will not, without us doing something, arrange things as we wish.
On the other hand:
"Malthus was right. It's hard to see how the solar system could support much more than 10^28 people or the universe more than 10^50. - John McCarthy 1987
So on a 1% annual growth rate we will be ok for 2,100 years or if we conquer the universe, 28,000 years.
So nothing we should consider now.