Researchers Say Human Population at Critically Low Levels, Need More Babies to Survive
Researchers Say Human Population at Critically Low Levels, Need More Babies to Survive – LifeNews.com
A new study has found that human populations may need a fertility rate of at least 2.7 children per woman – far higher than the long-accepted 2.1 – to reliably avoid long-term extinction. The research, published April 30 in PLOS One and led by Takuya Okabe of Shizuoka University in Japan, challenges decades of demographic assumptions, Phys.org reported.
Threshold fertility for the avoidance of extinction under critical conditions
The developed countries now face a low fertility crisis. The replacement level fertility (RLF) is conventionally considered to be 2.1 children per woman, in which demographic stochasticity arising from random variations in individual offspring numbers is ignored. However, the importance of demographic stochasticity casts doubts on the adequacy of the replacement level fertility of 2.1, especially in a small population.
