Creationists mostly deserve kindness and understanding, not scorn.
Not anymore.
Their blatant attempt to corrupt and twist science in order to re-package their delusion is unforgivable. It will be met head on with reason and logic.
-There are more bacteria in the world than there are grains of sand on all of the beaches of the world (and many grains of sand are covered with bacteria). They exist in just about any environment: hot, cold, dry, wet, high pressure, low pressure, small groups, large colonies, isolated, much food, little food, much oxygen, no oxygen, in toxic chemicals, etc. There is much variation in bacteria. There are many mutations (in fact, evolutionists say that smaller organisms have a faster mutation rate than larger ones16). But they never turn into anything new. They always remain bacteria. Fruit flies are much more complex than already complex single-cell bacteria. Scientists like to study them because a generation (from egg to adult) takes only 9 days. In the lab, fruit flies are studied under every conceivable condition. There is much variation in fruit flies. There are many mutations. But they never turn into anything new. They always remain fruit flies. Many years of study of countless generations of bacteria and fruit flies all over the world shows that evolution is not happening today.
Mankind has been studying evolution of these lifeforms (bacteria, fruitflies) in a laboratory setting for less than 100 years. Earth is over 4 billion years old (as shown by radiometric dating) and has had life for most of this period. Simple forms of life such as bacteria were among the first to appear. With bacteria splitting (=reproducing) sometimes more than once per hour the number of generations that bacteria have gone through is mindbogglingly large. Our human minds are very limited when it comes to the perception of large timespans or quantities, we simply can't get a good grasp on just how large some things are. We already have difficulty imagining how our ancestor lived 2000 years ago, but this is a mere 100 generations at most.
It is not surprising that bacteria and fruitflies haven't changed into anything significantly different during the time we've studied them. There simply hasn't been the time. The naive view that some people seem to have of evolution that it is supposed to happen in front of our eyes. It doesn't. It is an exceptionally slow process where substantial changes typically only take place on a timescale of millennia if not longer.
This is what makes it such a difficult subject to study as you can't simply put a few creatures in a lab and watch them evolve wings. Instead, a main source of clues is from fossils we have to dig out of the ground. And fossilization happens to be an incredibly rare process as it needs just the right soil under the right conditions. Many species rarely or never ventured into these areas. It is a minor miracle (not of the mystical kind) that we've found as many fossils as we have. As for the "lack of transitional fossils": Every fossil a transitional fossil. There is no magical missing link between species A and B. The process is extremely gradual and you wouldn't be able to see the difference between 2 specimens where one is a direct descendant of the other 30 generations later.