The point at which the simes run out of Gens to Kill, then die in attrition. This discovery was made by a sime mathematician named Zelerod and his prediction was ignored by general sime society.

(Source:  Index Card File.  House of Zeor) Within a hundred years, perhaps less, the human race will be extinct because of the increasing population of simes living longer adult lives, Killing so many Gens that there won't be enough for simes to survive. Shows mathematically that the only survival is through the channel.  Now the juncts accept it, a few come to the Householdings and people like Andle get more desperate.

(Source:  Index Card file.  UNTO ZEOR FOREVER)  World population figures stood over 300% past Zelerod's Doom.  With channel intermediaries, world could support a population of 50% sime if necessary -- but they had a long way to go to reach that figure.  Ilyana says Zelerod was wrong, sudden end to Tecton wouldn't end human race -- human race is still mutating rapidly.  Two paths are open:  Distect way only road to evolution.  In big world, Gens would survive and create their own Houses and join the Distect, a world with only emotionally healthy people (very different people from UNTO's time).

Destruction precedes emergence of something better.

If Tecton holds off too long, pressure of simes to find own mates among Gens will get too strong, destruction will get TOO great, and humanity WILL end (the Distect's Doom).

Simes who kill are parasites -- they will die out along with their hosts.  But it is NOT the basic sime nature to kill (basic nature is symbiosis.)