why a lunar tally stick?
Why am I creating a lunar tally stick? It has to do with menstruation and measurement.
We have good evidence through the work of people like Alexander Marshack that humans of around 500,000 years ago had the cognitive faculties to create artifacts with notation that tracked the lunar and seasonal cycles of the world they lived in.
These artifacts have groups of markings mapping map onto an 'observed' lunar cycle of dark moon, crescent to full, full, and full to dark. Basically groups of 3, 11-13, 3, 11-12 depending on the phase of the moon in any particular month. The lunar cycle is 29.5 days and over the course of two months of observation the numbers are self-correcting.
It's pretty understandable what the benefits of this kind of notiation might have been - knowing when seasonal changes occur, when migrating animals or fish appear, and tracking pregnancy for example. But what propelled these people to measure the moon in this way? What told them the moon was key?
Based on the work of Judy Grahn and also Chris Knight in England, the answer is menstruation. Consider these facts. Women's menstrual cycles always entrain to other womens' cycles over time (except when artificially altered). In the absence of artificial light, womens' menstrual cycles entrain to the cycle of the moon with ovulation usually at full moon and bleeding at dark moon.
What might have been going on a half million years ago that had enough periodicity that someone noticed the linkage to the moon's phases? Why are women's menstrual cycles called 'moon cycles'? There is lots of evidence (read those two authors above) pointing to menstruation being what kicked pre-humans into human consciousness.
That said, why a lunar tally stick? Because I think they are fascinating. They teach us about where measurement came from - and in answering that question opens the door to a different origin story than the one of "adam and eve".