Biologists have discovered and recognized just under 2 million different species of living organisms on Earth, most of which are small things like insects. This seems like a big number, and so perhaps you think the Age of Discovery is over, that we have our own planet pretty much figured out.

Far from it.

Various studies have estimated that anywhere from 5 to 100 million species are on Earth right now, and so we are less than half way to discovering the basic units of biodiversity. In understanding life, we biologists are working on a puzzle with most of the pieces still hidden in the box.

A new species of jumping spider, Ilargus, from Ecuador

As an arachnologist, I confront our ignorance when I collect spiders in a tropical forest. Typically, half or more of the species I find are new to science. Pictured here is one of the new species I found on a 2010 trip to Ecuador -- this male has bright blue palpi that he shows off to the females.

On the one hand, it's tremendously exciting to find a species new to science every day you look. On the other hand, it's depressing to think how much work remains. And only a few of us are doing it.

And so, Borneo's forests await.

Previously in this series:

Spiders in Borneo: Introduction

Text and images © W. Maddison, under a Creative Commons Attribution 3.0 license (CC-BY)