Please can you give me a simple definition of evolution?

Question

Please can you give me a simple definition of evolution?

Answer 1

Evolution is the process of certain individuals that are best adapted to their environment passing their genes on to their offspring.  Over time, the population will become dominated by this genotype.  When this genotype becomes markedly different from the original (so much so that these individuals cannot breed with individuals of the original genotype) a new species has developed via evolution.  

Answer 2

Genetic "accidents" happen.  Sometimes they are for the better, that is, they allow the organism to reproduce more effectively.

Any changes that favor reproduction and/or survival, allow that organism's genes to be carried forth into the next generation.  Then, if those traits breed true, the progeny will have a similar reproductive advantage.

With sufficient time, the changes can be quite remarkable.  

Answer 3

A change in a population's gene frequency.

Answer 4

A change in the allele frequencies of a population, over time.

Answer 5

Evolution is a change in the average genetic makeup of a population of organisms.  

Answer 6

Are you asking about purely biological evolution, or about evolution in general?

In general, evolution is the lasting change, over time, that results from new things that pass through a filtering process.  That's the way that organisms, computer programs, languages, cultures, ideas, and countless other things manage to evolve.

With biological evolution, the "new things" pretty much means "random genetic changes" and the filtering process means "natural selection toward reproductive fitness."  So, any random genetic mutation that makes an organism better able to pass its genes on to a new generation, is more likely to be passed onto several succeeding generations.  And any random genetic mutation that makes an organism less able to pass its genes on will probably be lost before too many generations have passed.

But, as evolution-driven computer programs have shown, almost any way to make new things (random number generators, for instance) combined with almost any way to pick out only certain new things (utility functions, for instance) can lead to evolutionary development.