> Reincarnation can be falsified by either
> proving there is no afterlife, a terminal
> experiment at best, or in my opinion by proving
> that human remote sensing cannot be real.
> Unfortunately, such experiments are no longer
> being funded.
I asked for what you'd consider a disproof. What you gave is hard to satisfy. Remember that extraordinary claims (such as reincarnation) require extraordinary evidence. Also, the burden is on the shoulders of the one claiming there ARE spirits and there IS reincarnation to show satisfactory evidence. It's not fair to say "I believe outrageous idea A. Since you can't disprove it, my beliefs are true." just like it wouldn't be fair for me to claim that a UFO took me up in their ship and then expect you to either accept my statement as true with little or no evidence or to disprove it.
It's difficult to disprove reincarnation or life after death partly because our access to the universe is limited (we can't look everywhere for these disembodied entities). It would also be difficult to disprove claims like "I have an invisible dragon in my garage" if I make the dragon have the right characteristics. The religious belief in spirits, I think, has evolved to be in this "nondisprovable" form. The properties are bizarre enough that scientists can't get a hold of one to study them, yet it has important qualities for the psychological happiness of its believers.
Does the belief in spirits and reincarnation better explain biology, psychology, the human condition, etc. then a naturalistic explanation? I don't think so.
Observations suggest that when a person dies their body decomposes without coming back to life. In some cases, a person that has stopped breathing for a short period of time or been in a coma, or otherwise appears to be dead, can be brought back to normal functioning. There's no good evidence that any clinically dead body (for a significant period of time such as a day or two) has ever resurrected.
Bacteria that have been dormant for millions of years have been brought back to normal functioning when they are warmed up. If those bacteria had spirits what were they doing for millions of years? If they can float around for millions of years what's to stop spirits from floating around for ever? Bringing back frozen humans has yet to be accomplished. How long would frozen humans or other higher organisms with reincarnated spirits (say mice or dogs) have to be frozen to eventually be brought back to normal functioning before you would discard the belief in reincarnation? Or, would you suggest that a different spirit took the body after it was unfrozen?
There's no good evidence that anything like a spirit or soul exists when a person dies. The thing, if it exists, doesn't seem to weigh anything or interact with the universe via the known forces.
> So in that context, althought some species have
> reached dimunishing returns, overall the
> advance of evolution has been towards higher
> forms of consciousness and intelligence. I
> expect that souls, if they exist, have gone
> through similar transformations.
It appears to me that life on Earth evolves towards well-adapted forms, not necessarily "higher" forms of intelligence. Some organisms today are very intelligent (such as humans, apes, cetaceans, other large mammals, etc.), but many remain of low intelligence (bacteria, insects, other small organisms). I suspect a similar process occurs on all inhabitable planets.
If all souls make progress, on average, and unless new primitive souls/spirits keep appearing then you'd expect ONLY fairly highly developed organisms. The large number of primitive organisms which exist today suggests that the reincarnation idea doesn't adequately explain the diversity of life.
Also, if the goal of evolution is to create higher beings then why does it take so long? If God or individual evolving spirits were influential in modifying the biological situation then I would expect humans to have developed billions of years ago. It seems like there was a lot of wasted effort. If I were God I'm sure I could do a much better job.