under lab conditions, scientist studying the evolution of bacteria got a bacteria that uses glucose for energy, or "food", to start using fructose as energy as well(the bacteria in question could not process fructose originally, no change in control group).
how? by introducing them to an environment that had required amounts of glucose for the bacteria culture to survive, and fructose. about a 50/50 split. after a certain amount of time, they moved bacteria in the culture to a new environment that was predominantly fructose. they found that, most of the bacteria died shortly after the change, but some did not. some had spontaneously(seemingly) gained the ability to process fructose. after allowing the bacteria to reproduce and introducing it to an all fructose environment, and the bacteria continued to reproduce, consuming fructose for energy.
this is a perfect example of how evolution works. a stress is placed on a being, and individuals with accidentally mutated genes that provide a beneficial trait which makes them able to deal with their environment better, tend to survive. the first bacteria that gained the ability probably couldn't do it very well. a very low efficiency would be probable. but that bacteria can now survive just that much easier, and when nothing is threatening its reproductive potential, it will thrive. after enough time passes, and enough generations, the fructose consuming bacteria will get better at it, until they have a fully developed ability to process fructose efficiently.
you could not call the fructose consuming bacteria the same species as the original, as the original could not process fructose, the control group did not see any changes, and you know beyond all doubt that no fructose consuming bacteria went IN to the petri dish(lab conditions, after all), so where did they come from? evolution is the only logical explanation(that does not depend on the existence of sky-daddy)
