The close of 2010 marks the end of the UN International Year of Biodiversity,
but the issues remain, and with them a surprising number of fundamental
unanswered questions. These are explored in a Q&A article –
commissioned for BMC Biology
as a contribution to the BioMed Central cross-journal thematic
series on biodiversity research – by Anne Magurran, author of two key books
on measuring biodiversity.

We all take it for granted that biodiversity is important,
suggesting that at least we know what it is, but it turns out to be surprisingly tricky to define in practice: the
key questions being diversity where, when and of what. In the light of these
difficulties it is perhaps not surprising that we do not know to within an
order of magnitude how many species there are – Magurran quotes one informed
estimate which puts the number anywhere from 3 to 100 million, and that’s
without scratching the surface of the microbiome.

Clearly
there is still a lot we don’t know about biodiversity, and its steady erosion
means that we are losing the chance to find out. The most striking contribution
of BMC Biology to the Year
of Biodiversity – and the biodiversity
series – to date is the description of a completely
anoxic metazoan species. We must all do what we can to ensure that all the
other species that undoubtedly remain to be discovered are not eliminated
before we find them. Magurran has some suggestions.

Kester Jarvis

Assistant Editor, BMC Biology