Parm, it’s all due to some wonderful stuff called DNA however the beginning of life is at the moment attributed to a simpler chemical called RNA. Somehow 4.5 billion years ago, in a hot chemical quagmire a collection of complex chemical structure was formed which was living, it could reproduce itself. It is thought that this microscopic entity was quite close to the structure of present day bacterias although, it’s make up was completely different. For example it didn’t breathe Oxygen, it is thought that it might have breathed a chemical called Ammonia and it expelled Oxygen. It also, in its structure contained a crude DNA structure.
From this humble beginning all life on Earth evolved dictated by changes in the DNA molecules that were part of their structure. Plants, Insects, Bacteria, Animals, Fungi, Algae, all life contains their own DNA molecules which dictate their continued existence.
So for Jeremey, our snail there has been, for some reason, a small change in her/his DNA. The spiral is wrong. Maybe it might be wrong but it might help Jeremy eat a plant that he/she couldn’t eat before and therefore survive and breed more snails like him/her.
Over the millions of years that life has existed on our Earth, now and then, new life , created by old life, experiences a slight change in the DNA, and that means that the new life is slightly different from the life of its parents (plants, animals, fungi ….). If the new life survives, that life will create more new life in it’s form, evolution has taken place.
Hope this makes sense Parm. Any thoughts? Write them in the ‘Leave a Reply’ box.