Tropical-temperate patterns

C. Geographic Patterns among Species 1. Tropical-Temperate Patterns... 

For two decades, the role of lipophilic chemistry in the evolution of mesograzer host range was heavily influenced by the enemy-free space hypothesis by Hay et al. (1987). This theory predicts that small herbivores consume and inhabit seaweeds that are chemically defended against larger, more mobile herbivores such as fishes and urchins. Support for these patterns can be found in several contexts from temperate North Carolina (e.g., Duffy and Hay 1991, 1994) and New Zealand (Taylor and Steinberg 2005), and the tropical Caribbean (e.g., Hay et al. 1990) and Guam (e.g., Paul 1988 Cruz-Rivera and Paul 2006), and the Antarctic (Huang et al. 

It is likely that the lack of agreement of results concerning the immunoglobulin levels in children with PCM stem from the fact that the values found in children in the subtropical and tropical populations are often compared with values from the temperate regions, where it is now abundantly clear that the serum immunoglobulin patterns in the white race differs significantly from patterns in the black race. Furthermore, the nutritional status of each group of children must vary from country... 

In contrast to patterns for lipophilic secondary metabolites, water-soluble phlorotannins (i.e., polyphenolics produced by brown seaweeds) were initially reported to be more abundant in temperate than tropical Indo-Pacilic seaweeds.123-125 However, this apparent latitudinal pattern has not held when tested in additional locations in the Caribbean.126127 The paucity of phlorotannins in some tropical seaweeds was attributed to their ineffectiveness against tropical herbivores,128 30 although phlorotannins from temperate seaweeds can deter some tropical herbivores.125 Because geographic patterns of phlorotannins and their impacts on herbivores are unclear, it is difficult to determine how allocation patterns of phlorotannins relate to the ODT. 

Several surveys have been undertaken to evaluate possible habitat or behavioral patterns in MAA distribution and content, but only a few general trends in MAA occurrence are evident.107-110-112117 Analyses of 382 species reveal that 95% of tropical species, 80% of temperate species and 82% of polar species have detectable levels of MAAs (Table 15.3). Palythine, shinorine, porphyra-334, mycosporine-glycine, asterina-330, palythinol, palythene, and mycosporine-2-glycine have been found at all latitudes. Other MAAs are less frequently reported and have more limited distributions however, this may be a function of insufficient data and not a true representation of MAA occurrence. 

In temperate climates, natnrally occnrring smallpox had a seasonal incidence similar to that of chickenpox and measles, with more cases occurring in the late winter and spring. Most likely, the association of increased survival of the virus at lower temperature and hnmidity contributed to the seasonal pattern. In tropical areas, there was less seasonal variation and the illness occurred year-round (25). 

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