Archaeological Amerindian and Eskimo cranioskeletal size variation along coastal western North America: relation to climate,the reconstructed diet high in marine animal foods,and demographic stress

A quantitative bioenvironmental study of cranioskeletal size has been made of a latitude-ordered sequence of 14 series of adult skeleton sets (N=305): the archaeological remains of aboriginal maritime peoples inhabiting the west coast of North America between southern California and the Arctic. Of eight osteometric parameters of cranioskeletal size developed, the most important are partial skeleton volume (PSK) and cranial capacity (CC); and the principal bone-affecting environmental factors are the northerly climate (CLIM2c), the reconstructed diet deficient in calcium and overabundant in animal foods and vitamin D (DIET3c), and demographic stress (DSg). Prior research has demonstrated that cranioskeletal size increases with geographical latitude and decreases under dietary calcioprivation and unphysiologically high birth rates. Upon linear multifactorial statistical analysis our main finding, limited to the Amerindian subsequence (n=11 series) from the Santa Barbara Channel, the San Francisco Bay Region and the Northwest Coast, is that PSK and CC vary in direct proportion to CLIM2c, and inversely with DIET3c and DSg. Controlling for the latter two osteoantitrophic factors, coastal Amerindian female PSK rises by 9% between 34 and 54°N latitude, CC by 5%; and the male incremental rates are somewhat higher, 13 and 10%, respectively. This newly discovered climate-dependent race cline, an example of Bergmann's Rule, is interpreted as factual evidence of a mid-Wisconsin or earlier arrival date for the first Palaeoindians. Cranioskeletal size of the very small (n=3 series) Western Eskimo subsequence approximates the northernmost values of the coastal Amerindian distribution. © 1998 John Wiley & Sons, Ltd.     

Cranioskeletal Size Variation in San Francisco Bay Prehistory: Relation to Calcium Deficit in the Reconstructed High-seafoods Diet and Demographic Stress

An osteometric–statistical study of residual rickets (RR) skeletal plasticity has been made of a time-ordered sequence of 11 series of adult skeleton sets (n=251) from shellmound sites around San Francisco Bay (the Bay) spanning the three archaeological horizons of Central California Indian prehistory in this region: Early (EH), Middle (MH) and Late (LH). To control for major differences of subsistence ecology and ethnolinguistic affiliation, the Bay sequence was further subdivided into four subregions: East (EB, Costanoan), South (SB, Costanoan, high acorns), West (WB, Costanoan, low acorns) and Northwest (NWB, Coast Miwok). In the eight EB series, a non-linear downward trend in cranioskeletal size was observed between EH and LH2, coinciding with a modest upward trend in the RR-15B score. To ascertain if food calcium deficit (CADEF) can explain the observed secular decline in cranioskeletal size, the evolving aboriginal Bay archaeodiet—relatively high in marine mammals, birds, fish and calcium-rich mollusks—was reconstructed by the diet grid method: in the three subregions with large stands of oaks (EB, SB, NWB), CADEF rose from negligible in the EH to moderate in the LH, as the subsistence base became more dependent on leached acorn meal for energy. Temporal and areal variation in Bay cranioskeletal size relates mostly to CADEF, demographic stress in females (DS), and the ‘male nutritional advantage interaction co-factor’ (MNAIC), in descending order of importance. This study has also confirmed the existence of the San Francisco Bay Indian physical type.     

Secular decline in cranioskeletal size over two millennia of interior central California prehistory: Relation to calcium deficit in the reconstructed diet and demographic stress

An osteometric study of residual rickets (RR) skeletal plasticity has been made of a time-ordered sequence of fifteen series of adult skeleton sets (n=359) from the Great Valley of central California (GV), spanning the three archaeological horizons of California Indian prehistory in this region: Early (EH), Middle (MH) and Late (LH). By least-squares linear regression analysis, a clear and continuous downward trend obtained in cranioskeletal size in both sexes, proceeding from EH to LH in the GV sequence, pari passu with a steady upward trend in the RR-15 score. To ascertain if dietary calcium deficit (CADEF), a known cause of active rickets, can explain the observed secular increase in RR, the aboriginal diet was reconstructed by the diet grid method: CADEF was found to rise from borderline in the EH, to moderate in the MH, to severe in the LH, as the subsistence base shifted gradually away from hunted prey, and storable seed foods—mainly leached acorn meal—became the dominant source of energy. Further regression analysis has shown that the secular upward trend in CADEF is highly correlated with the temporal clines of the GV sequence, directly with the RR-15 score, and inversely with cranioskeletal size: in round numbers, one grade of CADEF brings about a loss of 120 cm³ or 4 per cent in partial skeleton volume. Two biocultural influences—demographic stress (DS) in females, and the less common ‘male nutritional advantage interaction co-factor’ (MNAIC)—modulate the primary bone antitrophic CADEF effect: DS enhancing, MNAIC ameliorating.     

Growth curves of immature bones from a Scottish island population of sixteenth to mid-nineteenth century: Limb-bone diaphyses and some bones of the hand and foot

Growth curves were prepared for length of the diaphyses of the six major long bones of the limbs and for length of the calcaneus, talus, cuboid and the first metacarpals and metatarsals, of ages up to 20 years including several immature and many full-term fetuses. Most curves showed what appears to be a consistent adolescent growth spurt at about 17 years, but the number of specimens supporting these parts of the curves is too small for the validity of this spurt to be beyond doubt. The fetal diaphysis lengths were similar to those of Fazekas and Kósa and other recent populations but, compared with curves prepared from the Maresh radiographic data for recent caucasoids, the island diaphyseal growth rate, starting at about 4 months after birth, fell progressively behind so that, by 18 years for example, the femur was 90 mm shorter and the humerus 60 mm shorter than the Maresh equivalents. These findings accord with the short stature of the island adults (male mean 166.2 cm). The growth curves were closer to those of some ancient peoples, Amerindian, caucasoid and negroid, than to contemporary caucasoid. There is evidence of a secular change in growth in this island region because the calculated mean height at 18 years of this earlier island population is at the present time achieved by boys by about 14 years of age. Thus it is argued that the earlier population was affected by stunting factors. Although there is no skeletal evidence of malnutrition, there is plenty of evidence that the way of life was full of hardship in which the children shared. They took a full part in the arduous work involved in farming marginal-quality land; the houses were damp, cold, smoky and dark; they were overcrowded although, mainly because of the high infant-mortality rate, families were not large.     

Growth curves of immature bones from a Scottish island population of sixteenth to mid-nineteenth century: Shoulder girdle,ilium, pubis and ischium

Growth curves were prepared for length and various other dimensions, including some innovative ones, of the scapula, clavicle, first rib, ilium, pubis and ischium of ages up to 20 years including several immature and many full-term fetuses. Most curves showed, like the previously reported diaphyses of the limb bones, what appears to be a consistent adolescent growth spurt at about 17 years, but the number of specimens supporting these parts of the curves is too small for the validity of this growth spurt to be beyond doubt. The fetal dimensions were similar to those of Fazekas and Kósa and of other recent populations. For the post-natal stages of growth, no data are available for comparison but there was close correspondence with the growth curves of some ancient peoples, Amerindian, caucasoid and negroid, whose limb-bone growth rates had also been shown previously to be well below those of contemporary caucasoids. Thus it is argued that the shoulder-girdle and hip-bone data provided further evidence that this Scottish island population was affected by stunting factors. Although there is no skeletal evidence of malnutrition, there is plenty of evidence that the way of life was full of hardship in which the children shared. They took a full part in the arduous work involved in farming marginal-quality land; the houses were damp, cold, smoky and dark; they were overcrowded although, mainly because of the high infantmortality rate, families were not large.