Many mutations are neutral because of the degeneracy of the genetic code and because they often occur in the so-called 'junk' DNA. However, these don't create visible phenotypes and thus they shouldn't be included in any discussion on evolution.
Most mutations are harmful. It's true. For every beneficial mutation, there may be thousands of harmful ones. That's where the 'natural selection' part comes into play. To put it simply - those mutations which are beneficial are selected for, whilst those which are harmful are selected against. Simple as that. By beneficial mutation, we mean one that increases an organisms chance of survival and reproduction. Likewise, by harmful mutation, we mean one that decreases an organisms chance of survival and reproduction.
It doesn't require a scientifically trained mind to draw a conclusion: If an organism has a beneficial mutation, which increases it's chances of survival and reproduction, then this organism will live longer and have more offspring. Based on heredity, these offspring have a good chance of inhereting these beneficial mutations, increasing it's frequency in the population. This beneficial mutation becomes the norm, and provides the template from which other beneficial mutations can spontaneously arise. Thus, organisms keep evolving, continually producing bodies better suited to a specific niche, with nature acting as the fitness judge, jury and executioner.
That's evolution in a nut-shell. Take it or leave it.
I'll leave you with a quote from one Douglas Adams, author of 'The Hitchikers Guide to the Galaxy', descibing his own brush with Darwinism;
"It fell into place. It was a concept of stunning simplicity, but it gave rise, naturally, to all the infinite and baffling complexity of life. The awe it inspired in me made the awe that people talk about in respect of religious experience seem frankly silly beside it. I'd take the awe of understanding over the awe of ignorance any day"
Most mutations are harmful. It's true. For every beneficial mutation, there may be thousands of harmful ones. That's where the 'natural selection' part comes into play. To put it simply - those mutations which are beneficial are selected for, whilst those which are harmful are selected against. Simple as that. By beneficial mutation, we mean one that increases an organisms chance of survival and reproduction. Likewise, by harmful mutation, we mean one that decreases an organisms chance of survival and reproduction.
It doesn't require a scientifically trained mind to draw a conclusion: If an organism has a beneficial mutation, which increases it's chances of survival and reproduction, then this organism will live longer and have more offspring. Based on heredity, these offspring have a good chance of inhereting these beneficial mutations, increasing it's frequency in the population. This beneficial mutation becomes the norm, and provides the template from which other beneficial mutations can spontaneously arise. Thus, organisms keep evolving, continually producing bodies better suited to a specific niche, with nature acting as the fitness judge, jury and executioner.
That's evolution in a nut-shell. Take it or leave it.
I'll leave you with a quote from one Douglas Adams, author of 'The Hitchikers Guide to the Galaxy', descibing his own brush with Darwinism;
"It fell into place. It was a concept of stunning simplicity, but it gave rise, naturally, to all the infinite and baffling complexity of life. The awe it inspired in me made the awe that people talk about in respect of religious experience seem frankly silly beside it. I'd take the awe of understanding over the awe of ignorance any day"
