Earth belongs to the bugs

To a first approximation earth is the world of the archaebacteria. To a second approximation it is the world of the bugs:

A Pair of Wings Took Evolving Insects on a Nonstop Flight to Domination - New York Times - Carl Zimmer

A little over 400 million years ago, their six-legged ancestors came out of the water onto dry land. They have evolved into an estimated five million living species - dwarfing the diversity of all other animals combined. Even if you throw in all the known species of plants, fungi and protozoans, insects still win.

Insects are also a success in terms of sheer biomass. Put all of the insects on a giant scale, and they will outweigh all other animals, whales and elephants included.

And insects are also ecologically essential. If all humans decided to leave for Mars, taking all the vertebrates with them, the disruption to life on Earth would be incomparably less than the catastrophe that would ensue if insects disappeared. Forests would probably collapse, rivers and oceans would be poisoned, and many other animals would starve...

Carl Zimmer's blog is fantastic, btw.