Burial

I must admit that I am not a very historically minded person. However, in reading about early man and the Neanderthals I have found new interest in the subject, I have been converted from my previous history-hating self into a person who cannot wait to learn more. What has done this? In reading about early man and the Neanderthals I found that they buried their dead. While this perhaps seems to be a trivial discovery and not one that would change one's mind about the likability of history, it certainly made a difference for me and I wish to attempt to share the wonder that I gleaned from this knowledge.
The burial of the dead is, cross culturally, a significant event. Various cultures perform the task differently, but still the ritual of burial is recognized: some build huge structures to remind people where someone was buried as the ancient Egyptians did, others, such as the Greeks often practice cremation – burning the body to ashes – to be placed in an urn in a special place in the house. The funeral may be a small grieving affair, a joyous procession with music and dancing, or a shrieking wailing group that pound the earth in grief. At this point we do not really know what was involved in terms of ceremony when the Neanderthals buried their dead, but the presence of red ochre and bone tools or jewelry indicates that there was more to it than just dumping a body into a hole.
Burial is perhaps the strongest evidence towards some sort of religion in these prehistoric peoples. That the dead were covered and laid to rest with items or paint-like substances suggests that there was a respect for the dead and perhaps, belief that their souls continued on in an afterlife. To think that so early on, creatures of the earth were contemplating other worlds and spirits or the dead is a wonderful thought; that so early in their development people were expressing wonder and doubt of the absoluteness of their own world makes one think more of them. Instead of seeing early mankind as lower beings or primitive, instead one can see that they were capable of ‘higher’ thought, they perhaps wondered about death and what it meant for the individual. These musings could have lead to belief in some higher being or powers that, while they did not look to the stars to find, they instead sought them out in the heart of the earth.

This does bring to light one question that I have: As far as burial goes, if someone does not believe n life after death or a higher power of any kind, why would they bury their dead with a headstone or anything to mark their body? Can Burial be separated from religion? Or are they mutually related?