As I level my dragons, I've ended up with multiple individuals of different levels. Past juvenile I can use any of them to breed. Does a different level have any effect on breeding?
Updated with latest information
From what has been read/told/seen with my own eyes, the dragon order has no beaering on the type of dragon you will get. However with a recent patch (1.13.0) it has been stated that breeding higher level dragons (15+) will increase the chance of getting a rare dragon from the pairing.
You can check out my question and its answers for more information on breeding chances here: What are the chances of breeding a type of dragon?
At level 10 they are more likely to breed rare dragon types like rainbow and sun and such. For normal combo's, there's really no point. They do give you more money past juvenile though, so I always get my dragons to lvl 10 right away. EDIT: This seems to be completely wrong, read the fourth comment. Sorry.