Biodiversity has become one of the most important conservation values that drive our ecological management and directly inform our environmental policy. This paper highlights the dangers of strategically appropriating concepts from ecological sciences and also of uncritically inserting them into conservation debates as unqualified normative landmarks. Here, I marshal evidence from a cutting-edge research program in microbial ecology, which shows that if species richness is our major normative target, then we are faced with extraordinary ethical implications. This example challenges our (...) well-received beliefs about biodiversity and it invites us to critically rethink the nature of this concept so that a more robust understanding of biodiversity and of its role in conservation policy could emerge. (shrink)