There have been numerous well-documented extinctions of indigenous species caused by the introduction of non-indigenous predators and pathogens.
由于引入了非本地的捕食者和病原体，已经有许多本土物种灭绝的记录，证据确凿。
2
Many are found in tropical and subtropical areas of the world, where the accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial pathogens.