Very interesting movie, but take the opinions of the scientists shown in the movie with a grain of salt, since they are everything but objective. Burying a dead body with a tool is far from being evidence of belief in the afterlife, or any belief at all. It's just a sign of respecting the personal property of the deceased and shows, that Homo Naledi was capable of feeling emotionally attached to things, not only showing emotions for other members of their species. Scientists projecting their personal beliefs and views instead of interpreting the facts, sadly that more common than it should be.