What bobad says is generally accepted these days, I think (I like saying "I think" because that's what Charlie Darwin put, self-effacingly, on top of his famous tree diagram).

"///Incidentally, Darwin didn't "teach" anything. ///

No kidding."

NO, Josep, really no kidding. Darwin was not a teacher.

"I know a guy who had a heart attack and died for a short time. When they revived him he had no short term memory."

*sigh* Well, he didn't really "die" then, did he? I suggest that his memory loss was due to his brain being deprived of oxygen for a short time while his heart was temporarily stopped. Sometimes the most boring explanations have a far better chance of being the truthful ones. That philosophy, if it is one, is what makes us atheists tick. The whole world is so...wonderfully ordinary...