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Title: Past equable climates, mixed assemblages, and the regression fallacy

Conference · · Bulletin of the Ecological Society of America; (United States)
OSTI ID:7264611
 [1]
  1. Univ. of Minnesota, St. Paul, MN (United States)

Equable climates are often invoked to account for Pleistocene mixed (disharmonious) assemblages of plants or animals. However, mixed assemblages are defined by comparison with only modern distributions. Many modern assemblages, such as the western ponderosa pine and the northern hardwoods forests, are mixed assemblages when compared to Pleistocene distributions. Thus, explaining past assemblages with no modern analog by invoking a past equable climate ignores the fact that many modern assemblages have no past analog, yet the modern climate is not considered equable. This logical error is analogous to the regression fallacy in statistics. A change in the variability within assemblages through time cannot be detected if only the presence (and not the absence) of extreme species are considered. Because species also respond to historical and other non-climatic variables, interpretations will inevitably be biased toward equable paleoclimates. A more direct approach is to count those species that presently reside in equable climatic zones. If the species typical of modern equable zones are absent, then the proposed equable paleoclimate becomes tenuous.

OSTI ID:
7264611
Report Number(s):
CONF-940894-; CODEN: BECLAG
Journal Information:
Bulletin of the Ecological Society of America; (United States), Vol. 75:2; Conference: Annual Ecological Society of America (ESA) meeting: science and public policy, Knoxville, TN (United States), 7-11 Aug 1994; ISSN 0012-9623
Country of Publication:
United States
Language:
English