We found that wilderness areas act as a buffer against extinction risk. The global probability of species extinction in non-wilderness communities is over twice as high as that of species in wilderness communities. The buffering effect that wilderness has on extinction risk was found in every biogeographical realm, but was higher for realms with larger remaining extents of wilderness such as the Palaearctic [Di Marco 2019: 26].
The remaining intact ecosystems of Earth—which are increasingly seen as essential for providing ecosystem services on which humanity relies and maintaining the bio-cultural connections of indigenous communities—have been neglected in efforts to conserve biodiversity. This is largely due to a belief that these areas are less vulnerable to threatening processes and less rich in threatened biodiversity, thereby having lower conservation value [Di Marco 2019: 585].
These areas are important because they host highly unique biological communities and/or represent the majority of remaining natural habitats for biological communities that have suffered high levels of habitat loss elsewhere [Di Marco 2019: 585].
Di Marco, Moreno, et al., 2019, Wilderness areas halve the extinction risk of terrestrial biodiversity, Nature 573, https://www.nature.com/articles/s41586-019-1567-7%C2%A0.
 The Palaearctic is the largest of Earth’s eight biogeographic regions; it encompasses Europe, North Africa, and Asia north of the Himalayas (https://en.wikipedia.org/wiki/Palearctic_realm).