He reasons that an organism can memorize pleasure, and then change itself so that it will get more of the same in generations to come. So he has organisms with perception, who like joy-trips, and wished they'd evolved more of them in their own life-time.
I can just hear these organisms now: "If only we'd known what pleasure we could have had earlier! Now it's too late! But let's pass on what we have learned to our progeny whom we produce without this pleasure! Yeah! Great idea!"
This is what I would say is a classic example of misunderstanding one of the basic concepts of natural selection or evolution. When I was 12, I heard the example of a creature evolving a long neck to reach food higher up being explained. My big question: "How could evolution or 'nature' have
known to suddenly mutate a gene and give the successive generations of creatures longr necks in order to reach the food?"
My confusion lasted about 10 minutes. In a very simple example: "Evolution," "nature," or even a given member of this species didn't "
know to do anything." The creatures with longer necks were able to reach the food, so they ate and lived to pass on their gene to their offspring. Long-neck genes and all. Meanwhile, the ones with the shorter necks died off, not being able to feed themselves. "Nature" didn't need to "know" or "desire" anything at all. The "long-neck" gene continued to be passed on and evolve because that trait allowed them to reach food.
So, sex being the act of reproduction, the creatures that have more sex will reproduce more successfully. Animals (in general or those within a given species) that enjoy sex more will inevitably have more sex and reproduce more. Those that enjoy it less will have it less, and reproduce less.
Now specific to the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse]: the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] is just a pleasurable reaction to a specific type of stimulation. It's not as if some generation of humans (or whatever) suddenly said, "if only we could enjoy sex even more..." and bam, the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] evolves. Rather, as those organisms who enjoyed sex more, had more sex and reproduced more, the successive generations were made up increasingly of creatures/animals that enjoyed sex moreso than their evolutionary ancestors. As the "sex results in pleasureable nerve response" genes get passed on and evolve, the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] evolves as a
logical extension of this process - this process being
natural selection. Those creatures that experience [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] more, have more sex due to a heightened enjoyment of sex.
As for desire, it has little to do with evolution, near as I can tell. In fact, the question: Which came first, the desire for [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] or the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse]? doesn't even make much sense to me, because desire isn't really a part of the evolutionary process (not at the biological level, anyway).