By Fiona Hodge

Exactly who else inhabits our world? It’s the sort of question you might think had been answered by now… but we’re still struggling to get to know our neighbours. We don’t even know the size of the neighbourhood: estimates of species number range from 5 million to 100 million species. So far science has identified about 2 million. Why? Well quantifying the biodiversity on planet Earth is much like doing a fundraising stock-take at The Warehouse. There are nowhere near enough stock-takers, an overwhelming diversity of stock, and the stock is all over the show.

There are complications in any inventory. Products or species must be classified, which can quickly become a nightmare on the front line. What should be done with the two Black & Decker blue orbital sanders? One is with a dustbag attachment and one is without? And what about the dustbag attachment sold separately? Is this a case of variation in a single product, or are these three different products? Three tally marks under one product heading, or one tally mark under three product headings?

These kinds of questions get even more complicated in a biodiversity stock-take where appearances of individuals in a species can vary far beyond the variation found in Black & Decker orbital sanders. Height, hair colour, shape and skin colour all vary in humans. Dramatic differences in appearances can also occur in species along gender lines, or by age, or by their environment. Consider the peacock and the pea-hen, the tadpole and the frog, and the taupata (Coprosma repens) on windy and sheltered banks. How can our stock-takers know if and when the new-to-science crust on the rock will turn into a fleshy seaweed?

In order to classify species taxonomists need to study biodiversity to get a sense of life cycles, population variability, gender differences, reproductive strategies, and environmental responses. This taxonomy is what really slows the biodiversity stock-take down, but this is also what truly reveals the nature of our neighbours. Having a list of latin words is only useful if the latin translates into useful logical descriptions of discrete species.

We need to know our neighbours in order to know whether they are changing, and in order to understand our world. Speeding up the biodiversity stock-take is crucial. We need more taxonomists, more funding and more of an appreciation for scientists collecting basic species information.

What better time than now, the International Year of Biodiversity, to step up to the challenge.