A criticism of eugenics policies is that, regardless of whether "negative" or "positive" policies are used, they are susceptible to abuse because the genetic selection criteria are determined by whichever group has political power at the time. Furthermore, many criticize "negative eugenics" in particular as a violation of basic human rights, seen since 1968's Proclamation of Tehran as including the right to reproduce. Another criticism is that eugenics policies eventually lead to a loss of genetic diversity, thereby resulting in inbreeding depression due to a loss of genetic variation. Yet another criticism of contemporary eugenics policies is that they propose to permanently and artificially disrupt millions of years of evolution, and that attempting to create genetic lines "clean" of "disorders" can have far-reaching ancillary downstream effects in the genetic ecology, including negative effects on immunity and on species resilience.