The point is, he is intervening in the natural process, and NOT allowing it to take its natural course. And not doing it for a greater design? Why did he become a doctor?To save LIVES, many and plural; to PREVENT deaths, that would occur without INTERVENTION. He became a doctor in order to have power (knowledge) to affect a wide array of lives, and assure their futures. This seems to be a greater design(unless, of course, he only became a doctor to be rich and have at least one Mercedes!).
You acknowledge that we are, and have been 'modifying' breeds and species for a long time, but we are not yet 'creators', until we come up with something completely new. The fossil record is of full of 'modifications' of life forms; purely natural evolution, or possible 'interventions' as we are and have been doing for some time?
Pause a bit before you respond; we may agree that there are signs of both factors at play, to some extent, but does intervention/decision arise ONLY with us humans?