"Race" specificity and the femur/stature ratio.

This inquiry explores a series of problems related to the femur/stature ratio first raised by Feldesman et al. (1990). In particular, we used a revised data set and a more elaborate research protocol to address questions pertaining to: (1) whether the femur/stature ratios of three quasigeographic "races" ("Blacks," "Whites," "Asians") are statistically significantly different; (2) whether these are statistically (as opposed to biologically) coherent groups; and (3) whether the "race"-specific ratios are more accurate than the simple generic femur/stature ratio. We used ANOVA, ANOCOVA, post hoc analysis, k-means cluster analysis, linear discriminant functions, and approximate randomization to determine whether the group differences in the ratio were significant, and to assess the coherence of the "racial" groups themselves. We used validation procedures including mean absolute deviation, mean squared error, and Pitman's measure of closeness of a known sample of 798 femur/stature pairs to compare the accuracy of the generic ratio and the group-specific ratios. The results confirmed that the "Black" femur/stature ratio is significantly different from those of "Whites" and "Asians"; however, group coherence was poor, with results barely better than chance. We found that "race"-specific ratios slightly outperform the generic ratio when "race" is certain, but the gains are small for the assumptions required. More significantly, however, we found that when "race" attribution is uncertain or unknown, as in paleoanthropology, the wrong ratio (or the wrong regression equation) performs poorer than the generic femur/stature ratio. As a result, we recommend that researchers continue using the generic femur/ stature ratio to estimate stature in pre- and protohistoric populations. An alternative equation, a generic regression, yields even better stature estimates; however, we urge further study before recommending that researchers use this instead of the more thoroughly tested generic femur/stature ratio.

Simple adnexal cysts: the natural history in postmenopausal women.

Transabdominal and transvaginal ultrasound (US) examinations were performed in 184 asymptomatic postmenopausal volunteers to determine prospectively (a) the frequency and natural history of simple adnexal cysts in healthy postmenopausal women and (b) the relationship between cyst activity and both hormone replacement and length of time since menopause. Eighty-three simple adnexal cysts were found in 52 women. Thirty-two of 184 women (17%) had 37 cysts identified at initial examination; 46 new cysts appeared in 31 women (11 of whom previously had cysts). Forty-nine women with 72 cysts were reevaluated with subsequent US scanning over a period of 3-23 months. Thirty-eight of the 72 cysts (53%) disappeared completely, 20 (28%) remained constant in size, eight (11%) enlarged by 3 mm or more, two (3%) decreased in size by 3 mm or more, and four (6%) both increased and decreased in size on repeated examinations. No statistical relationship was found between presence of cysts or cyst activity with respect to the type of hormone replacement or length of time since menopause.

Femur/stature ratio and estimates of stature in children.

The present study examines the relationship between femur length and stature in children between the ages of 8 and 18 years. In previous investigations, my colleagues and I reported the surprising finding that femur length bears a nearly constant relationship to stature in adult humans regardless of ethnicity or gender. This earlier study revealed that the femur/stature ratio averages 26.74% in adult humans, and that using the ratio to predict stature from femur length yields remarkably accurate estimates. The current study shows that femur/stature ratios of children between the ages of 8 and 11 differ significantly from their older counterparts. Between the ages of 12 and 18, there are no significant differences due to age in the femur/stature ratio; however, there are significant differences in this age group attributable to gender. This study also shows that the worldwide average adult femur/stature ratio does not adequately describe children in this age range. This study strongly documents the adolescent growth spurt in the femur/stature ratios of both males and females at the precise time one would expect to see the spurt occur (10-12 in females; 12-14 in males). This growth follows a nearly identical trajectory in both genders, with relative femur growth dominating before the peak years of the growth spurt, and relative stature growth dominating afterward. This accounts for the ratio's rise to maximum values just before peak growth, and its decline toward the adult ratio thereafter. These findings require us to use separate adolescent femur/stature ratios of 27.16 (females) and 27.44 (males) to estimate the stature of children between the ages of 12 and 18. Preliminary testing shows these ratios to be more accurate in estimating stature than the properly selected Trotter and Gleser adult regression equation. Use of the adolescent male ratio with the Homo erectus juvenile WT 15000 results in a lower stature estimate (157.4 cm) than previously reported. It is suggested that continued testing of the ratio occur, but that the values herein derived may be useful in routine forensic cases involving children in this age range, and with subadult paleontological specimens.

Endometrial thickness after menopause: effect of hormone replacement.

Ultrasound (US) images of the pelvis were evaluated in 112 asymptomatic postmenopausal women to investigate the normal range of endometrial thickness (double-layer measurement) and the effect of hormone replacement on these measurements. Twenty-one patients (19%) had endometrial thickness greater than 0.8 cm. One patient, with an endometrial thickness of 2.5 cm, had endometrial carcinoma. Consideration of the known actions of estrogen and progestogen on the endometrium led the authors to believe that the clinical significance of an endometrium measuring more than 0.8 cm depends on the patient's hormonal status. Among asymptomatic postmenopausal women with an endometrial thickness between 0.8 and 1.5 cm, those receiving unopposed estrogen or continuous estrogen and progestogen need to undergo dilatation and curettage (D&C) or biopsy and those receiving no hormones or receiving sequential estrogen and progestogen should be encouraged to undergo D&C or biopsy. If a patient in one of the latter two groups is unwilling to undergo an invasive procedure, then US examination at 3-month intervals is acceptable. Any patient with endometrial thickness of at least 1.5 cm should undergo histologic diagnosis, regardless of symptoms or hormone status.

Prevalence of simple adnexal cysts in postmenopausal women.

This prospective study was performed with ultrasound (US) to determine the prevalence of unilocular, nonseptated adnexal cysts ("simple cysts") in healthy postmenopausal women and the relationship between cyst occurrence and both hormone replacement and length of time since onset of menopause. Transabdominal and transvaginal US were performed on 149 volunteers aged 50 years or older. Patients were classified according to hormone regimens (no hormones, unopposed estrogen, continuous daily estrogen and progesterone, and sequential estrogen and progesterone) and time since onset of menopause (less than 5 years, 5-10 years, and greater than 10 years). Simple adnexal cysts were found in 22 women with the aid of transvaginal and/or transabdominal US, yielding a relative frequency of 14.8% +/- 5.7% and a prevalence of 14,800 patients with cysts per 100,000 patients. No statistical relationship was found between cyst frequency and type of hormone replacement or length of time since onset of menopause.

Femur/stature ratio and estimates of stature in mid- and late-Pleistocene fossil hominids.

In previous limited investigations of the human femur/stature ratio we (Feldesman and Lundy: Journal of Human Evolution 17:583-596, 1988; Feldesman et al.: American Journal of Physical Anthropology 79:219-220, 1989) have shown it to be remarkably stable across ethnic and gender boundaries. In this study we evaluate the femur/stature ratio in 51 different "populations" of contemporary humans (n = 13,149) sampled from all over the world. We find that the mean ratio of femur length to stature in these populations is 26.74%, with a very restricted range of variation. When we compare mean femur/stature ratios of males and females, there are no statistically significant differences. ANOVA performed on a naive grouping of samples into "whites," "blacks," and "Asians" indicates that there are significant racial differences (P less than 0.001). When we subject these groups to Tukey's HSD procedure (a post-hoc test), we find that "blacks" are responsible for the significant ANOVA, being significantly (P less than 0.005) different from the other ethnic groups. "Whites" and "Asians" are not significantly different (P = 0.067) under the conditions of this analysis, although all these racial comparisons may be suspect given the small sample sizes. We tested the efficacy of the ratio in three situations: predicting stature of repatriated white Vietnam veterans; predicting stature in a random sample of South African blacks (of known stature), and predicting the stature of a single Akka pygmy. In the first and third cases, the femur/stature ratio does better than the traditionally recommended regression equation, while in the second case the predictions from the femur/stature ratio are less accurate than from the appropriate regression equation. These results encouraged us to apply this ratio to mid- and late-Pleistocene fossil hominids, where the choice of reference population for stature estimates continues to trouble workers. We estimated stature for a sizeable number of Homo erectus (HE), early Neanderthal (EN), Near Eastern Neanderthal (NEN), and early anatomically modern Homo sapiens (EAMHS) by using the simple relationship: stature (cm) = femur length (cm) * 100/26.74. Our results show that HE fossils are slightly taller on average than either EN or NEN samples, which do not differ significantly in stature, while EAMHS fossils are significantly taller than all three earlier groups. While these results are not surprising, our stature estimates for these fossils differ from currently published estimates based on sample-specific regression-based formulae.(ABSTRACT TRUNCATED AT 400 WORDS)

Morphometric analysis of the distal humerus of some Cenozoic Catarrhines: the Late Divergence Hypothesis revisited.

Washburn's Late Divergence Hypothesis (LDH) makes a series of predictions about the phyletic affinities of extant hominoids and also predicts the locomotor behavior of the "formative ape," the common ancestor to the African apes and humans, and of the earliest hominids. The present study explores some of these predictions in the light of distal humerus morphology. Multivariate analysis of distal humerus metrics, corrected for the within-groups distortion of shape by size, was used to compare a broad sample of 22 modern anthropoid taxa with 15 fossils from the Fayum, Rusinga Island, Ft. Ternan, Neudorf an der March, Kanapoi, Kromdraai, Lake Turkana, and Hadar. The results of this analysis support some aspects of the LDH, while other aspects are unresolved. Specifically, the distal humeri of the large hominoids are very distinct from those of other anthropoids; however, Hylobates is not associated clearly with either hominoids or monkeys. This suggests that "brachiation" (sensu Hylobates) is too specialized a behavior and cannot explain the common set of characteristics known to unify the hominoids. Among the large apes, there is no discrimination that can be made between the African apes and Pongo, and Homo appears only slightly closer to Pongo than to the other apes. This offers little insight into the question of whether humans did, or did not, go through a "knuckle-walking" stage in their ancestry. The Oligocene and Miocene distal humeri sustain Washburn's assertion that the "formative apes" resembled the suspensory quadrupedal platyrrhines like Ateles. The Miocene P. africanus specimen highlights the uniqueness of Hylobates in showing that this fossil "bridges" the morphology of the acrobatic cebids and the morphology of the larger apes; it appears to be clearly "intermediate" between the two groups. Hylobates, by contrast, has affinities with no fossil, does not connect with the apes, and is generally isolated except for its connection with colobines. Among the Plio-Pleistocene fossils, the Hadar sample proves to be quite primitive, and may be close to the point where hominids and pongids diverged. The Kanapoi distal humerus (KP 271), far from being more "human-like" than Australopithecus, clearly associates with the hyperrobust Australopithecines from Lake Turkana. The stratigraphically late Kromdraai distal humerus is the only hominid to be projected near Homo. The Plio-Pleistocene hominids generally evince a pattern consistent with the prediction of a late separation of hominids and pongids. But, the results of this study, like many before it, fail to resolve the central question of whether the last common ancestor of the African apes and humans "knuckle-walked." It is suggested here that this may be an unresolvable problem.

Further morphometric studies of the ulna from the Omo Basin, Ethiopia.

A reanalysis of the L40-19 fossil ulna from the Omo Basin, Ethiopia is presented. Using covariance adjustment rather than ratios to correct metric data for variations due to body size, a comparative sample reflecting 21 contemporary Anthropoid taxa, and both distribution-free and multivariate statistical procedures, this study indicates that the earlier conclusion drawn by McHenry et al. ('76), viz., that the fossil is "unique" among Hominoids, is essentially correct. This study also concludes, however, that although the fossil is projected closer to Pan and Homo than to Pongo, the distances are considerably greater than found between behaviorally similar modern forms. Consequently, aside from assigning the fossil on morphometric grounds to the Hominoidea, little else can be said about its possible locomotor habits or its ancestry.