Subrat Kumar suggests that we should preserve the DNA of vanishing organisms such as tigers so that they can be regenerated later (Nature 492, 9; 2012). But extinctions do not just represent the loss of species — they are the pervasive disintegration and destabilization of ecological networks.

Species are more than the sum of their genes: they are the manifestation of reciprocal interconnectivities between organisms and their environment (C. S. Elton Animal Ecology Univ. Chicago Press, 2001). Modern extinctions are an irrefutable symptom of habitat loss and the unravelling of biological processes. If we cannot preserve India's forests and mangrove swamps, for instance, then we cannot save its tigers.

Biotechnology has a role in conservation, but it is not the solution to extinction. Instead, we must protect the integrity of ecosystems and their inherent dynamics. Freezing the tiger's DNA amounts to little more than handing on the responsibility for our actions to the next generation.