Dig Deeper

Getting the hang of these small creatures, you begin to realise there is a lot more to them than many people think.
Where did they come from? When did they appear on earth? Or is it not quite that simple. They dont 'appear' on earth, they are an integral part in in.
But how what why when where?
You can find out more about them  ...
However now, we are going to ask the questions behind the small soil creatures. 
Where did they come from? 
When were they first around? 
What is the geological relation with plants?
How do they go back in time with plants? 
Suddenly there are so many questions..
There is a whole new world to explore and discover.

Yet the arthropods - the ones with legs, are largely overlooked. There is even a scientific paper on why soil mesofauna are ignored (Ref..Link)  Basically, there are a al ot to count, and they are pretty hard to distinguish, so there arent many people around to count them. However I was one just such person. I was one of those who could. And did. I counted half a million small arthropods. It took three years. It was part of my PhD thesis on 'The Effects of herbicides on soil mesofauna'.  I was awarded the degree by Wye College, London University, then the most prestiguous Agricultural College. In the world. It is shut now.

Lets start with
When did the Soil Evolve?.Asking this question throws up just about every part of the curriculum you can imagine, so is ideal for interdisciplinary projects.  (link to Scottish Curriculm)
We have to go back in geological time frames, to study the evolution of the world most valuable long term asset - its soil. Starting with the zoology of these soil creatures, mixing with the botany around them,  controlled by the chemical conditions, exerted by the physical forces, the story of how the soil evolved brings together all these forces. And the soil animals gave me the clue to how it all fits together..
When did 'Higher Plants evolve? 
 We knwo fersn and mosses and 'bryophytes' have been around a long time. They all tend to need a lot of moisture. But when did 'Highr plants appear. 'Higher' doesnt mean taller, although in this case, it coincides. 'Higher' measn' further up the evolutionary ladder. It just so happens we are talking about trees, which alsoi happen to be taller!

ACTIVITY 
1. Determine when you consider the soil EVOLVED. If it is a living entity it must have developed over a period of time into the consistency and consituency that it is today. It is remarkably similar all over the world, despite every inch being different from the next.
2. Another grouop determine when trees first appeared on the planet.
Discuss what time frames each of you came up with, and whether they are the same.

It seems to have been around for a long time. But not 'forever'. Can you remember it in a reproduction of any geologial ages?
Make your prediction - and see how it matches up to this..


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