A basic theory of biology is that all life becomes more finely attuned to its niche over time when left in peace. Undisturbed ecosystems evolve to ever deeper complexity through the Darwinian process of cumulative adaptation. It is not so much a matter of being able to 'sense' the underlying constant factors making up its niche, but that these factors influence the nature of life at a reproductive and sub-sense level. Each species has a natural range, based on the accidents of reproduction and its cumulative adaptation to niche factors such as rainfall, predation, temperature, etc.

I argue that cosmic factors, including the age cycle of precession, are a part of the ecological niche of life on earth. A tree may not be able to 'sense' climate change such as a rise in average temperature by 0.1 degree, but such a change (especially over millions of years) can have a big effect on which genes are successful in the process of natural selection. Of course, cosmic factors are extremely weak by comparison to the immediate terrestrial environment, but my argument is that this weakness is counterbalanced by permanent regularity. The moon has circled the earth 50 billion times since the dawn of life. The lunar cycle may or may not produce immediate 'sensed' advantages, but this permanent regularity makes it plausible that species are adapted in deep subtle genetic ways to diurnal and monthly lunar cycles. Precession is similar. The earth's axis has precessed about 175,000 times since life first evolved. On the theory that there are twelve ages per precession, this makes about two million ages, each lasting 2147 years if the axial wobble rate has been constant, since our oldest genes came into existence.

I do not argue that our genes 'sense' the ages, but that the ages provide a cosmic structure of terrestrial time, and human culture is part of this cosmic structure just as a fish is part of a river. The fish may not 'sense' a small change in water quality, but will be affected by it nonetheless. Precession provides a basis for a theory of karma as causality, with deeply imbedded cycles within planetary history operating at very long time scales. This thread examines main events over the two such cycles within recorded western history to find evidence for this theory, examining whether the historical outlines of these ages are comparable. I think the evidence here is strong for a 2147 year wave pattern whereby human history reflects the main cosmic structure of terrestrial time.

The solar system barycentre, now under discussion at the Jupiter Influencing Sunspots thread, has a period of 179 years resulting from the cycle of the planets. It appears this planetary cycle exactly matches 1/12 of the earth's precessional cycle, suggesting entrainment between precession and the barycentre as a new scientific framework to consider the whole solar system as a unified dynamic entity.

So, although by and large life cannot directly 'sense' the ages, we do now have the capacity through astronomy to understand them. I argue that the patterns I have described here are just scratching the surface of the advantages for human life of such analysis.