Aineo said:
Kikyo, you had better take your own advise. Some Eastern religions believe you can be reincarnated as a cockroach, rat, etc. A little real research might do you some good.
The murderer of a brahmin becomes consumptive, the killer of a cow becomes hump-backed and imbecile, the murderer of a virgin becomes leprous - all three born as outcastes. The slayer of a woman and the destroyer of embryos becomes a savage full of diseases; who commits illicit intercourse, a eunuch; who goes with his teacher’s wife, disease-skinned. The eater of flesh becomes very red; the drinker of intoxicants, one with discolored teeth.... Who steals food becomes a rat; who steals grain becomes a locust... perfumes, a muskrat; honey, a gadfly; flesh, a vulture; and salt, an ant.... Who commits unnatural vice becomes a village pig; who consorts with a Sudra woman becomes a bull; who is passionate becomes a lustful horse.... These and other signs and births are seen to be the karma of the embodied, made by themselves in this world. Thus the makers of bad karma, having experienced the tortures of hell, are reborn with the residues of their sins, in these stated forms (Garuda Purana 5).
Not everyone who believes in reincarnation believes that animals reincarnate as people and even the ones who do believe this
believe that they will reincarnate higher not lower unless the person was bad (I hope you are not saying that John the Baptist was bad).
I'm not sure weather you only read half of what I said or half of your own quote but you should read these both again.