Evolution is a scientific fact that every decent thinker should accept

My opponent poses a question: "An repeatedly tested and through observation and experimentation confirmed explanation is like a fact". I do not agree, but it is important to note that my colleague offers no reason to accept this assertion." I can give you an example of what I mean with "is like a fact". For example you see a plant in the sun grow, and you see another plant in a shadow die. You ask yourself, why does the plant in the shadow die? Does it need sun to survive? Now you test through observation and experimentation if sunlight does affect the growth of the plant. You see that all plants that are in the dark die, and all plants in the sun grow. Now you can conclude that the plant that you just experimented and observed, in fact need sunlight to grow. Now that you have your conclusion, you test, rather or not that conclusion is true or not. If it is, you can consider it a fact, since it is proved to be true. The same goes for evolution. Scientists asked themselves why there is such a variety of species. They asked, too, since fossils show a slow change of species over time, rather is has to do with random changes or not and rather or not there is a non random component, that leads to this changes. They observed and experimented and came to the conclusion that there are random mutations within the species and that some of these mutations were more likely to be successful in the natural world than others. They saw that the individuals with negative mutations were more likely to die off. Those with mutations that helped them reproduce and survive were more likely to live and carry on their genes. All this can be seen in the fossil record and furthermore in the DNA, in which one can even see the mutations. Since it's a theory that is tested to be a 100% accurate, it can be considered a fact. A decent thinker would consider this argumentation logical, therefore accept it. If you are a decent thinker and come to another conclusion, test it, prove it, and receive your Nobel Prize. "The underlying implication being for the betterment of society or advancement of science or something, but why is it necessary?" I honestly do not either want to make this debate about religion vs evolution. So I'm going to show you another point. It simply shows us where we come from. And isn't that an important thing for us to know? You make decisions on where you come from, what you are now and where you want to go (in a metaphorical sense). If you don't know where our species comes from, you may make the wrong decisions on where we as a species want to go to. Which could lead to the annihilation of our species. "If we are all going to die eventually, then it would be reasonable to seek pleasure in the form of: Affirmation, physical, emotional, or avoid pain be it physical or emotional. So if a drug addict finds pleasure in numbing himself out that is fine" The problem with drug addiction is, that is tricks you into thinking that it is good for you, when in reality, you lose your social life, you have physical and emotional stress if you can't get the drug, you may rob other people to get the money for the drug. Furthermore it may destroy your body and brain, which in most definitions is not such a positive thing. I hope I could clear the questions that you had and make a clear point.