also:
Evolution can take place from individual to individual. We all have the basic DNA.Outside factors can cause DNA to 'switch'....(DNA Triggers)
Example:In a cave in Borneo 3 years ago scientists discovered a completely white spider, with a larger amount of eyes than a usual spider (and it is blind)...they tested its' DNA...decided it has been around for 25 years, and has the identical DNA to that of a wolf spider.
