Hi,
Actually, there is a natural propensity for females in human reproduction. I think the odds are like 41 to 40 for a zygote to be female. Makes sense in a genetic sense. To maintain a population, it takes females. A male can engender many children, a female relatively few. And giving birth is the biggest differential danger during the fertile years (which, until comparatively recently was the whole of the life expectancy).
I am. There are many assumptions made to get that (or any other figure) for future populations. Presently, most of the industrial nations would be having a population reduction if it weren't for immigration. China, as you pointed out, is already in a population draw down mode (although I doubt it will be as extreme as your analysis makes it). India and Africa are the jokers in that deck. As long as the culture is based on the concept of high infant and child mortality (thus making having a lot of children a benefit) but the technology is developing towards that of industrial countries (where having more than two or so children causes a population explosion) there will be problems.
A combination of local laws, a strong propaganda campaign, and tying foreign aid to reasonable population control could make the situation go the other way, and a population of 4 to 5 billion by mid century is not impossible.
--Pete
(06-02-2011, 02:08 AM)Lissa Wrote: The one hypothesis I can see for why western culture has so many females to males could be attributed to wars, ...
Actually, there is a natural propensity for females in human reproduction. I think the odds are like 41 to 40 for a zygote to be female. Makes sense in a genetic sense. To maintain a population, it takes females. A male can engender many children, a female relatively few. And giving birth is the biggest differential danger during the fertile years (which, until comparatively recently was the whole of the life expectancy).
(06-02-2011, 02:08 AM)Lissa Wrote: Is anyone else somewhat skeptical about the 9 Billion population figure?
I am. There are many assumptions made to get that (or any other figure) for future populations. Presently, most of the industrial nations would be having a population reduction if it weren't for immigration. China, as you pointed out, is already in a population draw down mode (although I doubt it will be as extreme as your analysis makes it). India and Africa are the jokers in that deck. As long as the culture is based on the concept of high infant and child mortality (thus making having a lot of children a benefit) but the technology is developing towards that of industrial countries (where having more than two or so children causes a population explosion) there will be problems.
A combination of local laws, a strong propaganda campaign, and tying foreign aid to reasonable population control could make the situation go the other way, and a population of 4 to 5 billion by mid century is not impossible.
--Pete
How big was the aquarium in Noah's ark?