Where do emotions come from?
That’s quite a general question; can you be a little more specific?
Looks at the name of the forum. 
Best I can guess is somewhere in the thalmus of the brain–I know that’s the area that gives a split second desicion regarding the general ‘good’ or ‘bad’ feeling you’ll have about a certain stimulus.
I have not researched this but could our human emotions be related to an instinctual reaction much like the hypothesis that our need for sleep developed from primitive human’s fear of predators, darkness, etc.
I can see, maybe, where emotions like fear and anger might be evolutionary advantages – but your point just then about sleep has me mystified, malachi. Sleep occurs in other animals – I don’t think it arose from a fear of predators or the dark.
This site has some very good information and illustrations that indicate emotions are formed primarily in the Amygdala and Hippocampus.
The process by which the soft grey tissue behind your skullbones knits impressions together and matches new input with existing libraries of stores experiences is known as “feeling”.
“Feeling” can be subdivided into “sensation” – the raw sensory data as experienced by the sensory receptor division of the beforementioned grey tissue – and “emotion”, which is the assessment and reaction portion of feeling, the cognitive part if you will.
If you happen to be in possession of a language and (therefore) a rich matrix of verbally structured conceptual patterns of thought, the emotional interpretation of experience can be coded into word-terms, which facilitates “thinking about” the entire event as a noun in relation to a lot of incredibly complex stuff.
If, on the other hand, you are – a puppy dog, let’s say – “emotion” is pretty much the terminal process by which you have cognition of the world you occupy. (i.e., you have sensations and, from them, emotions that include matching against previous experiences, but you don’t do much abstract contemplation of them).
We will assume (despite no SDMB rules forbidding canine participation here) that you are not a puppy dog. People, possessing language, tend to be unaware of the process of encoding emotion into verbal terms, to the point that they sometimes believe that they think without feeling, or believe that emotional processes are somehow not connected to reality and that “emotionless” thinking is. Actually, “thinking” is a meta process that builds upon emotional processes, and without emotional processes does not occur. (Unless you regard strictly mechanical rule-following processes such as those my CPU engages in to constitute “thinking”).