VaughanJB
Scrappy VIP
Well, at some point in time desire arose, because we have it today in most species. Courting behavior doesn't happen by accident or chance. It is a deliberate act. So somewhere along the line it seems to have become necessary or preferrable to self-replication with no desire.
I specifically referred to single-cell organisms. Ain't no courting with those.
In the wider context, I wonder if you're confusing pleasure with the need to reproduce? In reality, while we can assume many species indulge in sex for pleasure, it's not a proven thing in all but a handful of species. Still, making a deliberate decision to have sex might be pleasurable, that doesn't mean we're not also following an innate drive to reproduce. There are, after all, other ways to get pleasure.
As far as choosing to reproduce, how much of that in modern times is down to economics, rather than anything else? Our intellect can overcome our instinct when we try and rationalize our decisions. Not to mention the religious doctrines that wrap reproduction up with an official ceremony (often costing a lot!). It's almost a societal blessing for the act.
You've got to keep in mind, as far as life on earth is concerned, the human condition (species) is only a small part.