Question: do you believe in evolution?if you do could you tell me how it exactly happened?

Claire Shooter answered on 27 Jun 2014:

I absolutely believe in evolution – the evidence for it is overwhelming. I don’t think any other theory for the emergence and diversity of life has any merit whatsoever.

Evolution is what happens when an advantageous mutation is adopted by an entire species, causing a small but important change to it. This is all there really is to evolution, but people tend to think about it on a large scale of one species turning into something different. That’s exactly same basic process, but just looking at the cumulative result of thousands and thousands of these changes over millions of years.

Mutations are mistakes in your genetic code. You probably have about 6 new mutations yourself which weren’t in the DNA you got from your parents – they happen all the time. Most mutations won’t do anything – they end up in non-coding regions, or if they do end up in the coding part of a gene, don’t do anything important enough to have any effect. The next most likely thing is that the mutations will have a detrimental effect: they cause gene to function less well than they did before. If you make a typo in an essay you write for school, the chances that the typo has actually changed the word you were trying to write into one that better sums up what you’re trying to say are pretty low.
Very occasionally a mutation will make something work slightly better than it did before: perhaps a protein in your eye changes and your retinas become slightly more sensitive to light. If you’re a primitive animal and suddenly you have better vision that your friends, you might be better at catching food or avoiding predators. This means you are likely to survive for longer and/or breed more, passing this onto your offspring. Your offspring also do better than their peers, and have more offspring than they do. Gradually your children’s children’s children will make up the majority of the population. Eventually, everyone has the same mutation, and the evolution of your species has taken a little step forward.

Evolution is also a response to outside pressures. If you are part of a species that likes eating fish and eating fruit, but crocodiles keep eating all the ones who prefer fish, the ‘selective pressure’ this causes may mean that only the individuals who like fruit more survive. Gradually, the entire species will only be composed of individuals who only eat fruit, because all the ones who liked fish got eaten.