If we are but a mere by-product of millions of years of evolution, then there would certainly be no “choices” in aspects of life such as sexual orientation and morality. Instead, my DNA or genes would influence who I was. It would then have an impact on my upbringing, environment, education, government, home life, etc., etc. The reason is because Darwinian evolution believes in the continued improvement and betterment of the species of animal known as man.
Thus, if I am merely an animal and one that is continuously evolving, I would be forced to accept that whether I was good or bad would be based on my DNA. This is why Hitler believed he was right to exterminate all peoples that he did not like. He was living out his beliefs.
It is this reason why Margaret Sanger and Planned Parenthood can operate with impunity in the wanton murder of millions of babies in the mother’s womb. They are acting out the logical conclusions of their belief. Evolution makes us better and abortion simply weeds out the weak and inconsequential in their minds.
Therefore, if I am but an evolutionary blip, then I cannot choose. I could no more choose who I want to have sex with than what morals I wanted to practice. In other words, if my evolutionary genes did not offer me the ability to make moral choices, I could kill with no conscience, or assault another person, and should have the freedom to do so.
After all, we do not kill animals that use their base instincts to kill or assault another animal, so why should we do this with human animals? There must be a level of consistency if we are going to apply evolutionary beliefs and still say that how I live or who I sleep with is not a choice.