The millenium ark: How long a voyage, how many staterooms, how many passengers?

TLDR

Demographic forecasts predict a 500–1,000‑year “demographic winter” that will shrink tropical wildlife habitat, potentially requiring captive breeding of roughly 2,000 large terrestrial species, though biotechnology may help but cryotechnology will likely take decades to become viable. The study proposes that captive breeding should aim to preserve 90 % of the source population’s genetic variation for 200 years. The authors provide tables that estimate the minimum captive group size based on the group’s exponential growth rate and number of founders. They find that, in most cases, founder groups must consist of more than 20 effective individuals.

Abstract

Abstract Barring holocausts, demographic forecasts suggest a “demographic winter” lasting 500–1,000 years and eliminating most habitat for wildlife in the tropics. About 2,000 species of large, terrestrial animals may have to be captively bred if they are to be saved from extinction by the mushrooming human population. Improvements in biotechnology may facilitate the task of protecting these species, but it probably will be decades at least before cryotechnology per se is a viable alternative to captive breeding for most species of endangered wildlife. We suggest that a principle goal of captive breeding be the maintenance of 90% of the genetic variation in the source (wild) population over a period of 200 years. Tables are provided that permit the estimation of the ultimate minimum size of the captive group, given knowledge of the exponential growth rate of the group, and the number of founders. In most cases, founder groups will have to be above 20 (effective) individuals.