Free will exists

On the discussion of evolution, my opponent responds to some of the arguments I made, and added that this particular topic is tangential at the end. I will first address the notion that the discussion of evolution is "tangential" to the topic of free will, and then address my opponent's response to my arguments. The reason I bring up the process and nature of evolution is because it would shed light on what the brain is supposed to do (since the brain is the product of evolution). And as we all know, animals have brains so the animals could make decisions that would help them survive (reflexes, memory, etc) and increase their chance of genetic propagation. I expect my opponent would agree with this, since with this premise, free will indeed does not exist (due to the observation that all animal behaviors are controlled by the brain). With that in mind, one argument of mine is that humans are unique in the sense that we are capable to not be controlled by this "supposed function" of the brain. What my examples were are certain exclusively human behaviors that would seemingly go against what our brain is meant to prevent. Humans would put themselves in situations where they cannot propagate their genes. Examples of this are countless, and although my opponent can show how some of these examples could help humans propagate indirectly, I doubt my opponent can explain all of them (in fact, he hasn't tried to explain all the examples I have given in the previous rounds). Perhaps the most obvious and important example is our use of condoms and other contraception. While we still have urges to have sex (this would be one of those desires that we cannot control by free will) we have the ability to make the decision to use birth control so we do not propagate our gene. This is actually very staggering because it shows how different we are from all other organisms. If there was a kind of plant, that if eaten, would cause the consumer of that plant infertile, animals would avoid that plant at all cost, yet we humans are cultivating it and using it generously. Why would we want to make this decision if we do not have a free will? Surely, we must be able to make conscious decisions in order to have the desire to use contraception. If we cannot make conscious decisions, all our decisions must be ones that would help propagate our genes as that's what are brain is for. My opponent has asked me, "what mechanism [...] does the "conscious person" use for making the decision"? I shouldn't have to invoke a "soul" in order to assert we are able to make conscious decisions. Presumably, everyone who's reading this would currently consider themselves "conscious", meaning, they are aware of what they are doing, and they have the ability to stop reading this whenever he wants to without the feeling of being "forced (by their brain) to stop reading". Precisely, when I said we make conscious decisions, I am saying we have a thought (generated by the brain) and we can either execute it, or veto it and have the brain generate another thought. This is what I mean by consciousness and free will, and I can demonstrate this without invoking any magical substance. To sum up this round, I have showed that we are able to make conscious decisions (albeit generated by the brain), for they are conscious because they are decisions that would go against what is hardwired to the brain, demonstrating our ability to veto the decisions our brain would try to force on us. And the conclusion from this, is that free will exists. (in this round, we used the example of the usage of contraception). The sexual lust is what is programmed, I showed we are not biological robots since we can control our lust, and if we do decide to have sex, we use contraception which would destroy the purpose of the desire hardwired into the brain.