In fact, bananas exist to make more bananas. They are a product of natural selection. It just so happens that the most effective way for old-timey bananas to make more bananas was to be eaten by animals and have their seeds spread, so evolution dragged them in that direction.
Procreation is one of the core purposes of human sex, in the sense that anything has a purpose. However, "purpose" and "nature" don't reveal anything about morality. Humans have moved beyond just being creatures of instinct and self-preservation.Subjectivity can change the "purpose" of a lot of things but that is human influence not natural purpose. Heterosexual sex and gay sex are two different acts presumably each with their own separate natural purposes. Procreation is the natural purpose of hetero sex, but it has evolved through our own subjectivity to be used for a number of reasons and it's natural purpose probably comes somewhere towards the end of all the humanity based purposes but it doesn't negate the fact that its ultimate purpose is to keep the human race in existence. Everything cannot just exist because it exists.
Incidentally, there are a lot of theories about how homosexuality has been beneficial in an evolutionary sense. They range from maintaining a critical mass of productive adults in a family unit without overloading things with kids, to research that suggests that the sisters of homosexuals are more fertile than women in the general population, hinting at some sort of genetic predisposition that is carried through the female lineage. It's interesting stuff.
Evolution is driven by random mutations, but it is itself not a random process. Lots of things are like this. Take the atmosphere as a (poor) example. Each individual atom or molecule in the air is moving at random, however, the fact that the atmosphere as a whole sticks there on the earth's surface is far from random.Also, imo you can't argue for randomness and for the laws of nature in the same post. It's kind of talking out of both sides of your mouth...well actually you can do what you like but I'm not buying it!!!![]()
Bookmarks