Um, as an evolution stickler, what you describe is not evolution. Evolution, or decent with modification, is something caused by the combination of two factors. First, genetics are passed down from mother/father to their offspring. Second, there has to be natural selection.
In a very basic example, let us say dragons only eat tall humans with big ears. If dragons eat every human that is over a specific hight, over multiple generations, humans will get shorter. Why? Well, becuase if a dragon eats all the tall people, some of those tall people will not have actually had babies. The babies that were made will be likely to grow up taller, and they'll be eaten by the next wave of dragons. Again, some of those grown ups won't have had babies, so the number of taller people would, on average, be smaller!
Over thousands of years, the dragons will have caused the human population, on the whole, to become shorter.
Now, replace "dragons" with a massively complex ecosystem, and "Shorter/taller" with every single factor about a critter.
So...if they are changed, through magic, this is not evolution. Evolution would be affected quite a lot by magic in ways I can't figure. But...well, don't call it evolution if its some kind of magical mutation. That's something completely different.
The more you know!
Also, in the real world, the instant people could do something that made farming EASIER, they used it almost instantly. Cause farming without machinery or magic is haaaaaaaaaaaaaaaaaaaaaaaaaard and takes forever and leaves you tired and weary.
If a society gets magic, its going to use it. Like...almost immediately. Unless there is a very good reason for it to not use magic for everything. Like, say, magic is addictive and if you use it to much, you die of a magic overdose or something. Or, if you use magic for frivolous things, your head explodes and splatters all the walls around you with your gooey, juicy brains.
Mmm...
Brains...
So, another thing that magic and technology do, is they level the gender playing field. We've already seen this happen over the last century. With less dependence on pure brawn and more on mental agility and fine dexterity and other less "hit them with sword" skills.
I'd suggest you research the Industrial Revolution. See what that did to society, and think about how the rise of technology can be equated to the sudden discovery of magic.
A...Magical Revolution.
hmm...
Actually, don't write about that, I'm grabbing that idea.