The observational and epidemiologic studies relating increased latitude with increased risk for cancers suggest a possible role of sun induced vitamin D3 synthesis as the beneficial factor responsible for these observations.
At distance ranges of about 15 degrees in the Arctic Ocean, diversity of macrofauna and nematodes was found to decrease with increasing latitude, after controlling for depth (Figure 2b) [96], [96].
Although season was a strong predictor of serum 25(OH D, latitude was not as important as might have been expected based on the knowledge that ambient ultraviolet radiation levels (and particularly UVB) generally decrease with increasing latitude (r = −0.96 for annual ambient UVR) (Gies et al. 1999).
For example, echinoderm diversity along the eastern Australian coast down to Tasmania decreased with increasing latitude [85], similar to what we observed for 100x intertidal echinoderms.
Increasing latitude was associated with a decreased risk for lymphoma and both of its subtypes, retinoblastoma, and other/unspecified neoplasms.
Both measures of genetic diversity decreased with increasing latitude (Spearman rank correlations, one-tailed test, p<0.05 for each; Table 2).
There was a trend, however, toward reduced taxonomic richness for both macrofauna and nematodes with increasing latitude.
There was a tendency for headache prevalence to increase with increasing latitude.
There is a tendency for birds to become larger with increasing latitude, the southern subspecies being larger than those further north, except the Tasmanian form which is small.
For example, human height increases with increasing latitude [27] (as was also the case in our data set, Figure S3), and with decreasing mean annual temperature [28].
