noun
bottleneck effect
In population genetics, the loss of genetic diversity when a population undergoes a sharp reduction in size.
ボトルネック効果によって、集団の遺伝的多様性が減少することがある。
The bottleneck effect can reduce the genetic diversity of a population.
Founder effect: a similar loss of genetic diversity when a new population is established by a small number of individuals, rather than a population crash.
From English 'bottleneck effect', a term in population genetics.