The concept of evolution is simple. The consequence is astounding. If you are contemplating a wirra it would be a good idea to give a little thought to evolution. I do not need to go into the technical details of evolution. It is enough to state the rules. There are three.
Rule 1: The rule of variance;
Rule 2: The rule of inheritance;
Rule 3: The rule of selection.
That is really all there is to evolution. The first rule tells us that the individuals within a species varies between individuals. The obvious differences relate to size, shape, colour, etc. But there are also many unseen differences. There are also differences in the needs of an individual in order to flourish. There are also random changes in the actual DNA of an individual we call mutations.
The second rule tells us that the offspring will follow the characteristics of the parents. This means that the variances that occur in the parent will be carried through to the offspring.
Finally the third rule talks of selection. This is sometimes referred to as “survival of the fittest” although, unless your proof of “fitness” is “survival”, it is much broader than this.
If an organism has some sort of edge over other organisms it will tend to survive better. For example suppose that a saline patch occurs in the middle of a non-saline area and none of the surrounding plants can grow there. Then a plant that can tolerate salinity better than others will tend to thrive closer to the saline patch than the other plants. Its offspring will inherit this tolerance to a lesser or greater degree. The ones that thrive best in the more saline condition will more likely survive. And so the evolution of a salt tolerant plant is in process.
Now! The crux of the argument I just gave refers to a saline patch occurring. Was it always there? Presumably not or something would already be growing there. I call something like this occurring an “event”.
An event can be a fire, drought, flood, plague of locusts or many things. Events happen continually and changed the course of evolution many times in the past. There is much more to say about events and I will address this issue a number of times.
The point I am trying to make is that evolution wasn't a simple, unbroken path. If you read a book on the flora of an area it will probably talk of succession. I will address this subject later.
We have therefore, evolution striving to use every energy source possible and give a final, perfect balance. Then events constantly interfere with this so that everywhere we have different stages of succession. The result is the wonderful bio-diversity we have today.
An interesting point in the debate on evolution is the role of fire event in bushland. It is interesting to note that in a properly evolved environment there would be no place for fire. The fact that fire occurs demonstrates that there is some energy available. Certain organisms would evolve to use this energy. It is therefore my view that fire is a symptom of some sort of evolutionary failure. It tells me that something went wrong. That evolution was interfered with somehow to prevent the evolution of those organisms or to remove the ones that had evolved.
I suspect that in most cases it was a matter of one species becoming more dominant than necessary for the well being of the earth. I suspect that that species was us. I suspect that in most cases where fire is a problem that the grazing animals which evolved to remove the fuel load from the bushland was removed and therefore the ultimate grazer, fire, took over.