Some general similarities can be identified from these results
When compared against a uniform model, all three regions show most episodes of negative divergence before c 5,000 cal BP, and most of the positive divergences afterwards. When compared against exponential models the similarities between the three regions are even more striking. In all cases we see positive deviations between 6000 and 5,000 cal BP and a negative deviation after 3,700 cal BP. The results are thus consistent with a general rise-and-fall pattern, where the density of 14 C dates after the peak is higher than what is observed before.
The x-axes are in cal BP
Despite these broad similarities, our analyses indicate the presence of some local divergence in the SPDs. Fig 3 and Table 1 shows the output of the non-parametric pair-wise permutation tests. The global p-values (Table 1) are mostly non-significant, albeit the comparison between Aomori and Kanto returned a p-value of 0.0555. The local analysis (Fig 3) highlights portions of the SPDs where we observe significant divergences. While none of the divergences between the SPDs of Aomori and Hokkaido can be statistically supported (the global p-values are both >0.9), both regions exhibit some significant differences with Kanto. Aomori shows higher density in 14 C dates around 5,700 cal BP (corresponding to the decline observed in Kanto between the end of Early Jomon and the beginning of Middle Jomon), and a drop in density around 5,200 cal BP (when the SPD in Kanto is showing a steady growth). Although the global p-value of Hokkaido against Kanto is non-significant (p = 0.2752), we observe local positive deviations again at 5,700 cal BP, and a negative deviation at 5,000 cal BP, corresponding to maximum peak of 14 C dates in Kanto. Continue reading Some general similarities can be identified from these results