Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!spool.mu.edu!uunet!zephyr.ens.tek.com!tektronix!sequent!crg5!szabo
From: szabo@crg5.UUCP (Nick Szabo)
Newsgroups: sci.bio
Subject: Re: Why bother? (was Re: Terraforming, sun shield)
Message-ID: <21260@crg5.UUCP>
Date: 28 Feb 91 08:30:33 GMT
References: <5705@optilink.UUCP> <1991Feb22.164032.16901@zoo.toronto.edu> <1991Feb22.192438.26397@athena.mit.edu> <6956@harrier.ukc.ac.uk> <91057.110759JEWELLLW@PURCCVM.BITNET>
Reply-To: szabo@crg5.UUCP (Nick Szabo)
Organization: Sequent Computer Systems, Inc
Lines: 51

In article <91057.110759JEWELLLW@PURCCVM.BITNET> JEWELLLW@PURCCVM.BITNET writes:
>Right! Let's stop everything else and think about procreation!  (*I* think that
>'s so important that everything else can be suspended. Nudge, nudge, wink,
>wink.)

Before winking too much, think about the fact that since the advent of
birth control, sex != procreation.  In long-term thinking such as we're 
discussing here, this has serious consequences.  For example:

* Barring large, regular, and indefinitely lasting immigration 
  from Earth, a terraformed Venus would never be populated to the limit 
  of the created ecological niche.

* Space settlements in general will die out without such waves
  of immigration indefinitely into the future.

* Eventually, human population growth on earth could slow, reverse,
  and approach extinction.

This is based on extrapolation of growth rates among those 
populations with full access to birth control (generally the
more wealthy and well-educated).  They have followed the pattern of 
decellerating, and recently have crossed into the negative range.  
This can be seen by charting the birth rates in certain population 
subsets with greater access to birth control (such as college-educated 
women) or developed countries as a whole (most of which now have 
below-replacement birth rates).   

Despite the low birth rate, nearly 50% of all births in developed 
countries are still unplanned.   It seems, then, that the equilibrium 
birth rate given reliable birth control could be less than 1 child per 
couple, or a population drop of over 50% per generation.  As birth 
control becomes more reliable and widely available, this trend will 
spread until it becomes the dominant influence on the general 
population, and human population growth reaches the equilibrium
level.  It seems that there is little biological "parenting instinct" to 
motivate conception independent of sexual desire and keep this trend from 
reaching its ultimate conclusion.

Of course, new cultural forms could evolve that successfully motivate 
population growth despite the existence of reliable birth control, but 
such a cultural form has yet to be demonstrated.  France in particular 
has tried to encourage more births for "cultural survival" with little 
success.




-- 
Nick Szabo			szabo@sequent.com
"What are the _facts_, and to how many decimal places?"  -- RAH