If a Principle is a True Principle, it Seems it Should Work More than Once

   I am not as sure of evolution as most. I tend to disbelieve man came from the same ancestor as the ape. Perhaps, though, yes, perhaps we did. But, whether we evolved from another creature or not, I contend the evolution theory does have weaknesses. One, is that we only have one advanced species today, the homo sapiens. It seems to me that if evolution in s true principle, there should be on this earth now not just one species that has descended from prehistoric creatures, but two or three, at least, for if the principle works, it does just work once and stop, it keeps on working.
   Some would respond by noting Neanderthals, Cro-Magnons, Denisovans, and perhaps others, were separate species. While science does accord them as separate species, it remains that the homo sapiens are the only extant species. No other species -- perhaps ever -- has the mental acuity of the homo sapiens.
   The evolution process, supposing it is where we came from, has only worked once. I repeat, if a principle is a true principle, it does seem it should work more than just once.