Showing papers by "Robert S. Corruccini published in 1981"
TL;DR: It is suggested that asymmetry at the individual cusp level may be an indicator of developmental disruption and that environmental effects, particularly prenatal, may be greater for antimeric units than for occluding units.
Abstract: To improve our understanding of dental asymmetry, more anatomically discriminating measurements than maximum crown dimensions were used. The relation between antimeres and opponents in permanent first molar teeth of 192 twins were studied with respect to crown components measures. Several statistical methods were used to describe asymmetry and discrepancy of occluding units to correlate with developmental stress indicators such as zygosity, birth weight, and congenital disease. To varying degrees, developmental correlates are found to be associated with asymmetry. The amount of occlusal discrepancy seems to be a direct function of bilateral asymmetry. Heterogeneity of MZ-DZ total (among plus within pair) variances occurs fairly consistently for asymmetry but not for discrepancy, implying differential environmental influences between zygosities regarding asymmetry. Genetic variance estimates, designed to be unbiased by differences in environmental variances, are significant for cusp size but not for asymmetry. Our results suggest that asymmetry at the individual cusp level may be an indicator of developmental disruption and that environmental effects, particularly prenatal, may be greater for antimeric units than for occluding units.
71 citations
TL;DR: Detailed comparisons of the postcranium, cranium, and dentition of Pan paniscus, Pan troglodytes, and Homo reveal that except for slight differences in fore- and hindlimb proportions and the morphology of the shoulder, the postCranium of the two species of Pan are allometrically scaled variants of the same animal and one does not resemble Homo more than the other.
Abstract: Detailed comparisons of the postcranium, cranium, and dentition of Pan paniscus, Pan troglodytes, and Homo reveal that except for slight differences in fore- and hindlimb proportions and the morphology of the shoulder, the postcranium of the two species of Pan are allometrically scaled variants of the same animal and one does not resemble Homo more than the other. Nor does the postcranium of one species of Pan resemble Australopithecus more closely than the other when the effects of body size are controlled. The over all morphological pattern of the skull and teeth of the two chimpanzees is clearly different, however, but both are about equally distinct from the earliest known members of the family Hominidae.
66 citations
TL;DR: The effects of dietary consistency on arch growth have been of interest since Watt and Williams demonstrated that weanling rats fed a soft diet would develop significantly narrower maxillary arches, and the analogy between experimental work and the common maxillary arch collapse syndrome in humans is of interest.
Abstract: The effects of dietary consistency on arch growth have been of interest since Watt and Williams (Am J Orthod 37:895, 1951) demonstrated that weanling rats fed a soft diet would develop significantly narrower maxillary arches. One reason for this interest is the analogy between experimental work and the common maxillary arch collapse syndrome in humans (Kelley and Harvey, Vital and Health Stat, ser. 11, No. 162, USPHS, Washington, D.C., 1977) in which maxillary arch breadth decreases in relation to length. Unaccompanied by corresponding mandibular changes, this would lead to the development of buccal crossbite. The rat is a poor analogy for the human masticatory system because of the rat's bilateral prolinal chewing movements and mobile mandibular symphysis (Weijs, J Morph 145:107, 1975). We gained access to 17 Rhesus macaques (Macaca mulatta) imported from the wild as juveniles and assigned randomly to experimental and control groups. After acquisition, the animals were fed Purina Monkey Chow biscuits. For four to 14 mo before sacrifice, five of these animals were maintained on a diet of flour, applesauce, vitamins, powdered milk, casein, lard, and cholesterol, mixed to the consistency of fudge. Fibular and mandibular bone from all animals was examined histologically by Bouvier and Hylander (J Morph, in press), who found no differences between soft and hard diet fibulae, but reduced secondary Haversian bone in soft-diet mandibles. From
31 citations
TL;DR: While Symphalangus appears distinct from analysis of raw coordinates, it is less so when analytical procedures are included for controlling the influence of general size, which weakens arguments for maintaining siamangs as a distinct genus from Hylobates.
Abstract: Corruccini, R. S. (Department of Anthropology, Southern Illinois University, Carbondale, Illinois 62901) 1981. Analytical techniques for Cartesian coordinate data with reference to the relationship between Hylobates and Symphalangus (Hylobatidae; Hominoidea). Syst. Zool., 30:32-40.-Hylobatid cranial similarities are examined using Cartesian coordinates describing morphological landmarks. While Symphalangus appears distinct from analysis of raw coordinates, it is less so when analytical procedures are included for controlling the influence of general size. This weakens arguments for maintaining siamangs as a distinct genus from Hylobates. [Hylobatidae; Cartesian coordinates; allometry; crania.] Cartesian coordinates are an attractive alternative to the more traditional caliper measurements taken directly on organisms. By mapping morphological landmarks as they are projected onto an X-Y grid system, it is possible to get an evenly balanced representation of the organism's shape, and repetitive reliance on certain central landmarks (such as basion and nasion in craniometry) can be avoided. Interest in expression of data as Cartesian coordinates goes back to Thompson (1917) and further, but more recently a variety of analytical techniques have been proposed. Sneath (1967) gave an example of conversion of Thompson's transformation grids into contour maps which could then be analyzed by polynomial contouring. Benfer (1975) used the X and Y coordinates directly as input data for factor analysis of human crania. Ramaekers (1975) analyzed polar coordinates (which can be derived from Cartesian coordinates) describing tooth shape in a Paleogene primate. Lestrel (1976) and Lestrel et al. (1977) advocated Fourier analysis of morphological outlines (whose perimeters can be described by Cartesian coordinates). Bookstein (1978) developed a method of quantifying Thompson's transformnations as "biorthogonal grids," using (like most of the previous workers) an example from primate cranial shape studies. Scheibengraber (1979) proposed processing of
13 citations