So we're wired to have sexual desires. All living organisms are. Where does it come from...

>not knowing the difference between natural selection and evolution: the post

Hormones

It cuts off half sentence mid-elaboration and partII starts at a new lecture the next day

That was the end of the lecture material. They just cut out some random "next lecture we'll talk about blank" like they do in near every lecture.

See: respondent conditioning

Very few animals are continuously horny.
Most mate only at certain times of the year -- times when there'll be food and the babies will be most likely to survive. No point giving birth when everything is buried under five feet of snow.

Humans are a rare exception. Perhaps it encourages the father to hang around and contribute to taking care of mother and offspring, In a lot of animals, sex is more like rape, and then Dad goes away and never sees the female again.

The necessary to continue on through your genes. How is this even a question?

>So we're wired to write sentences beginning with the word "so".
So what?

Okay but how do you even know that for sure?

It's pretty cool how intelligent image processing can give a physiological response. Like something like bright like preventing sleep is pretty obvious, just light sensitive receptors doing their thing, but a image producing vertigo or arousal or that physically creeping sense of horror is hard to understand how it functions.
Obviously it's the basis for how you can even think, but still.

>Where does it come from?
rapes