Few ancient deposits contain a broad complement of ecofacts. Sandy deposits that preserve abundant carbonized macrobotanical remains often lack preserved bones, pollen, and phytoliths, and each of these materials varies in what is preserved. Submerged tropical deposits often preserve macro-plants but bones and shells may have leached away. Despite preservation problems, some ecofacts are found in most sites, and analysis of organic or mineral chemistry of decayed substances can give definitive evidence (Glaser
and Birk, 2011). Considered together, the different kinds of evidence can give solid conclusions about habitat and land use (Pearsall, 1995). Conclusions about past environmental patterns are unjustifiable when they derive from monotypic “proxies” whose relation to habitats
has not been experimentally established. Selleckchem DAPT Microfossil evidence needs to be compared to associated macrofossils, which provide complementary Tenofovir in vitro evidence and can be directly dated individually. Comparison of modern pollen to modern vegetation gives critical, often counter-intuitive evidence (Roosevelt, 2005:173–179). Studies of modern habitats show that pollen from closed tropical rainforests usually includes abundant herb pollen (e.g., Absy, 1979:49, 50, Figs. 12, 13, 17, 21, 23; 1985). The herb components donate disproportionately more pollen than do trees, because the latter are often fauna-pollinated. Modern savannas’ pollen DNA ligase is dominated by herbs to a high degree not seen in prehistoric Amazonian pollen profiles, which are consistent with the profiles of living forests (e.g., Absy, 1979:3, Fig. 25). Consideration of ecology and reproductive behavior of the living plant communities is a necessary interpretive basis for conclusions about
prehistoric assemblages. Another methodological problem is that researchers tend to treat modern human-influenced habitats, like the Brazilian cerrado, Bolivian plains, or Marajo grasslands, as if they are purely natural formations, which they call “savannas” (Absy, 1979, Absy, 1985, Iriarte et al., 2010 and Lombardo et al., 2013b:111; Oliveira, 2002). Yet these areas have long been managed for cattle pasture and cultivation by repeated cutting and/or burning (Barbosa and Fearnside, 2005 and Plotkin, 1999:129, 147–149; Roosevelt, 1991b:11–20; Smith, 1980:566; Walker, 2004:29). In evaluating habitat and land-use over time, researchers need to systematically compare prehistoric strata to both pre-human strata and modern strata of known vegetation cover and human management (e.g., Arroyo-Kalin, 2012). Without those comparisons, human impacts and natural factors are difficult to sort out from each other. For example, researchers assert certain habitats were unoccupied by humans (e.g., McMichael et al., 2012 and Hammond et al.