Misunderstanding Evolution
Evolution through natural selection is often portrayed as something more complex than it really is, which it’s a pity, as its beauty comes from the simplicity of the whole system. One of the unfortunate side-effects of this perception is the number of people that have been lured into the Intelligent Design “theory“. When watching, for instance, a nature TV show, or even reading what are considered serious science magazines, we often hear or read that “species x evolved defense y, or ability z“. This gives the impression of intent, of design, of something deliberate. Evolution through natural selection has no intent, it’s not deliberate. It’s just the application of very simple rules to increasingly complex systems.
The first thing to understand is the amazing amount of time that natural selection has had to work. Although natural selection can be seen in operation in very small time scales (e.g., bacteria becoming resistant to antibiotics), the current state of all systems (ecosystems) is the result of a long period of time. More than three billion years – that’s three thousand million years – more than 3,000,000,000 years. To put it into perspective, that’s 30 million centuries. All this time has given the rules of natural selection time to operate, creating the amazing complexity we know. The main rule is that whoever is the fittest (individually, or by cooperation among members of a species, or even symbiotically between species) will survive to pass the genes that create those abilities to the next generation.
Understanding how DNA works (the coding of the genes), we see how susceptible it is to mutations, through two main processes: changing of the coding itself on reproductive cells, through ionizing radiation or chemical interference (environmental); and through sexual reproduction, with the process of “fusing” two different sets of genes into one. These mutations can either code or change the code of some ability or characteristic. These random changes can be more or less drastic, and have a more or less profound effect on the organism as a whole when pitted against competition and the environment. Changes can also be neutral at the moment of their appearance, but later make a difference when the system changes. This is “all” there is to it. Natural selection can be seen in action in very simple computer models – that create very complex systems from very simple rules and inputs. This simplicity is something that most people, even scientists, have a tough time getting their minds around – but that Darwin so brilliantly discovered a century and half ago.
Bravo!