Many problems in comparative biology and biological anthropology require meaningful definitions of "relative size" and '(shape.'' Here we review the distinguishing features of ratios and residuals and their relationships to other methods of "size-adjustment'' for continuous data. Eleven statistical techniques are evaluated in reference to one broadly interspecific data set (craniometrics of adult Old World monkeys) and one narrowly intraspecific data set (anthropometrics of adult Native American males). Three different types of residuals are compared to three versions of shape ratios, and these are contrasted to '(cscores," Penrose shape, and multivariate adjustments based on the first principal component of the logged variance-covariance matrix; all methods are also compared to raw and logged raw data. In order to help us identify appropriate methods for sizeadjustment, geometrically similar or "isometric" versions of the male vervet and the Inuit male were created by scalar multiplication of all variables. The geometric mean of all variables is used as overall "size" throughout this investigation, but our conclusions would be the same for most other size variables.Residual adjustments failed to correctly identify individuals of the same shape in both samples. Like residuals, cscores are also sample-specific and incorrectly attribute different shape values to individuals known to be identical in shape. Multivariate "residuals" (e.g., discarding the first principal component and Burnaby's method) are plagued by similar problems. If one of the goals of an analysis is to identify individuals (OTUs) of the same shape after accounting for overall size differences, then none of these methods can be recommended. We also reject the assertion that size-adjusted variables should be uncorrelated with size or "size-free"; rather, whether or not shape covaries with size is an important empirical determination in any analysis. Without explicit similarity criteria, "lines of subtraction" can be very misleading.Only variables in the Mosimann family of shape ratios allowed us to identify different sized individuals of the same shape ("iso-OTUs"). Residuals from isometric lines in logarithmic space, projections of logged data onto a plane orthogonal to a n isometric vector, and Penrose shape distance based on logged data are also part of this shape family. Shape defined in this 0 1995 Wiley-Liss, Inc.

Ground-penetrating radar (GPR) was used to monitor 12 pig burials in Florida, each of which contained a large pig cadaver. Six of the cadavers were buried in sand at a depth of 0.50-0.60 m, and the other six were buried at a depth of 1.00-1.10 m and were in contact with the upper surface of a clay horizon. Control excavations with no pig internment were also constructed as blank graves and monitored with GPR. The burials were monitored with GPR for durations of either 12-13 or 21-21.5 months when they were then excavated to correlate the decomposition state of the cadaver with the GPR imagery. Overall, cadavers in sand were easily detected for the duration of this study at 21.5 months, even when completely skeletonized. Conversely, in clay it became increasingly difficult to image the pig cadavers over the first year of burial, even when they still retained extensive soft tissue structures.

During the past decade or so, considerable new data pertinent to the origin of modern humans have come to light. Based on these new data and reinterpretation of older information, three models have been offered to explain the development of modern people. These models-Brauer's Afro-European sapiens hypothesis, Stringer and Andrew's recent African evolution model, and Wolpoff, Wu, and Thorne's multiregional evolution model-have their roots in earlier models but differ from most by virtue of their worldwide perspective and integration of genetic and paleoanthropological data pertinent to modern human origins. This review presents a detailed discussion of these data in light of the three models. While convincing arguments can be offered for each of these models, it is concluded that none are unequivocally supported by the available data.

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