That's very vague. Unicorns meaning... simply horses with horns? No big deal. But if you bring magic into it, that's something else. Which incarnation of unicorns are we talking about? Most fantasies disagree on their precise characteristics.
This is true. If unicorns were real, we'd probably be used to it and it would be no big deal. But if they were magical...
Do they fly? Heal? Levitate objects? Can they only be summoned by a maidenly touch? Are they fully sentient? Would they work with humankind, or oppose it? Be utterly indifferent to it? Well, if you bring magic into it...that has great implications for the physical laws of the universe as a whole. The unicorns are only a side note. Would magic simply function as another form of energy? How would it be channeled? What possibilities would it introduce? Or would it override the laws of physics altogether, indicating that we dwell in an indifferent, chaotic universe? How would that be logically supportable? Would mankind find ways to control it, as with lightning?
Would they be just another subsection of horse then?
Most likely, based on cladogenics. It's unlikely for unicorns and horses to share almost all physical characteristics and not have a very close common ancestor. However, sentience is almost as big of a deal.
Yes, definitely.
My guess is that unicorns would be directly related to horses, but have evolved (from there) convergently with humankind to develop sentience. Possibly with the mediation of m *magic Alternatively, they could be closely related to humans, but have achieved a higher degree of intelligence and/or technological development, possibly co-opting genetically altered horse forms to take control of when their humanoid ones die.
I think the later would be more probable because of the unlikelihood of a magic allele There would have to be very strange occurrences for a trait like that to become dominant enough to spread throughout a population
Yeah. If we're talking about a magic allele, then I would think of magic as a sort of additional or enhanced sense, not a form of energy. Similar to the magnetic sense experienced by many magical creatures, or the way a mantis shrimp can see a far wider spectrum of color than you or I. It's hard to see how an allele would confer the ability to manipulate a certain form of energy. A buildup of genetic differences might do it. Think a horse population isolated for centuries in an environment that encourages interaction with energy in an unusual way. Sorry, magnetic sense experienced by many *migratory* creatures
These are all good points, though unfortunately I have to go to work now. It's been lovely talking with you