So why did this one isolated population survive when all other yellow-spotted bell frogs have disappeared?

为什么当其他黄斑响铃树蛙消失时唯有这群树蛙生存了下来？

youdao

Rather than compare the rate of depression and migraine of the relatives to those of the general population, the study compared rates within this isolated population itself.

这项研究没有将这些亲戚的抑郁症和偏头痛发病率与普通人群相比较，而是在这个隔离的人群内进行比较。

youdao

Many observers say those policies have contributed to creating an impoverished, undereducated and isolated population.

VOA: standard.2009.03.26

Its isolated population live just as they have for centuries, seeming half-pleased and half-snubbed at being left out of the hubbub of the neighbouring islands.

BBC: The perfect trip: The Dodecanese Islands

As part of the trial cull, researchers have trapped and euthanised sick animals two to five times a year from an isolated population in the south-east of Tasmania.

BBC: Cull 'cannot save' Tasmanian devil

It was also home to a distinct and isolated mosquito population, so the effect could be monitored closely with only a minor risk of mosquitoes from neighbouring areas contaminating the results.

BBC: The malaria parasite is spread by mosquitoes