I know I haven't blogged for a long, long time but I have some ideas I need to get down and, well lets face it, no one is going to publish a paper by a 41 year old, 2nd year Under grad!
This has been prompted by a discussion I had with a friend who is a firm believer in God. it got me thinking about one of the points that usually come up in these situations, where is evolution today? why is nothing changing? Of course the standard answer is because it happens over huge timescales but what if? what of evolution has indeed stopped? how could this happen and why did it start in the first place?
At this point I must make some assumptions about the reader. The first is that you are prepared to read this through to the end with out dozing off, another is you are versed in current theories involving planet formation and geological processes.
Darwin's theory of evolution by natural selection gives us the processes. The why it happens. A creature developers a variation which makes them more suited to a particular problem. They do better because of it and, as a result, their genes get passed on to the next generation. So far so good. The question that is raised next is how do these variations occur? Thanks to advances in gene research we now know that it is how the genes are encoded in our D.N.A. that make us what we are. It is changes in these codes that allow variation. So again where is this variation. One way we know for sure to affect the gene sequence is with radiation. The blasts of Hiroshima and Nagaski are proof of this. Here we see genetic mutations that deform their victims. but what if genetic mutation is the tool that allows the variation in evolution? Obviously I am not saying that a tumour is an advantage in the survival of the fittest but we know radiation can and does rewrite gene sequences. could long term, lower level radiation exposure drive evolution.
So now we must travel back in time, before life began, to the formation of the planet itself.
Current theory is that the Earth, its moon, the sun and all the objects in the solar system were created from the decaying remains of a dead star. These atoms slowly drew together under gravity to build every thing we are, see and can touch. Our sun was still young and cool but the Earth was warm. How can this be? (and doesn't it make a joke of the term Solar Constant?) The answer lies within the Earth itself. From my studies of geology I know that the Earth creates its own warmth through radiogenic heating. As radioactive elements decay they lose energy as heat and they decay because nature dictates that they have to be in a steady state. We can now accurately date the Earth thanks to knowing how long certain isotopes take to decay into a more stable form. Once in that form it no longer gives off energy so is no longer radioactive. Knowing this we can state now that the reason our Earth was warmer was because it was more radioactive then than it is today.
And so to my hypothesis. I believe that once the back ground radiation had dropped enough and other conditions allowed life to form, radiation was capable of mutating D.N.A. and these mutations formed the toolkit of life. As single celled and then multicelled creatures started to appear, radiation allowed for mutations to occur. Some proved worthless and the creature would have perished but small adaptations were able to mutate and where they gained an advantage the mutation was passed on. Could this be how evolution started? radioactive mutation caused by the environment?
As the eons passed radiation has reached a much lower background level. Is it possible that it can no longer affect the changes to D.N.A. that it did and we have reached a point where we are now frozen in these forms?
If this is so it may answer the question would evolution ever happen again? If radiation is indeed the driving force then no.
Thank you for your time