Dig Deeper‎ > ‎

Birth of the Earth

How and when did the complex living system we call 'soil' evolve?

The soil hasn't always been here. At first there was probably only water and sediment. The evolution of this soil ecosystem required the transformation of rock into complex organisms within 10 million years (it sounds a lot but a mere glance in geological speak). As continents collided, the chemistry, botany and zoology came together. The plants needed the minerals and animals to colonise the land, by transforming it.


My Theory

We need to explain the role of small soil creatures in creating the fragile living soil structure, and how these co-evolved and now co-exist. My theory is that soil evolved between 350-375 million years ago. It comprises three main elements - the role of soil animals, physio-chemical aspects, and essential elements.

My Theory

Three main aspects of the formation of soil


Soil Animals 
Role of Soil Animals

I make the prediction that the soil evolved around 350 mya, based on the animals found in the soil. Soil would not exist, but for the soil mesofauna. Soil does not merely “harbour” soil animals. They are part of what makes soil – as opposed to clay/minerals/sediment/sludge, a living entity.


Collision Course
Collision Course

Two continents collided to create new land. One of the properties pertinent to the 'invasion of land'/'creation of soil' appears to be the evolution of desiccation resistance. The small soil creatures like oribatid mites and springtails survive in different ways. Springtails spring out of the way. Oribatid mites roll up in a ball.



Essential Elements
Essential Elements

Volcanic dust provides all the essential elements for plants. It is hard to see how plants could have evolved anywhere else as there would not be that distribution of elements in say sand. If plants started to evolve in the stuff, then the little soil animals will come in and recycle those essential minerals when the plant died.