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Detection of gravitational waves (GW) from highly eccentric binary black hole (BBH) systems can provide insight into their dynamics and formation. To date, all of the LIGO-Virgo BBH detections have been made using quasicircular templates in their initial discovery. However, recent studies have found some of these systems to be compatible with high eccentricity in the LIGO band, ${e}_{10\text{ }\text{ }\mathrm{Hz}}g0.1$, possibly pointing to a population of sources that are challenging to detect. Current low-latency search methods used with ground-based GW detector data are not well equipped to detect highly eccentric sources. Template-based, matched-filter searches require accurate eccentric waveform models that are computational expensive. Unmodeled burst searches are designed to detected localized excess power and are unable to identify multiple isolated bursts, as would originate from a single highly eccentric BBH. Therefore, we propose a signal-based prior that can be incorporated into an existing GW burst search to target highly eccentric BBHs. Our eccentric burst prior is based on the Newtonian burst model described by [Classical Quantum Gravity 34, 135011 (2017)]. As a proof of concept, we test our method on simulated data and find that for intermediate $\mathrm{SNR}\ensuremath{\sim}3--6$ signals using the eccentric burst prior more effectively localizes GW bursts when compared to a uniform prior.

We present a new analysis of the profile data from the 47 millisecond pulsars comprising the 12.5-year data set of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), which is presented in a parallel paper (Alam et al. 2021a; NG12.5). Our reprocessing is performed using "wideband" timing methods, which use frequency-dependent template profiles, simultaneous time-of-arrival (TOA) and dispersion measure (DM) measurements from broadband observations, and novel analysis techniques. In particular, the wideband DM measurements are used to constrain the DM portion of the timing model. We compare the ensemble timing results to NG12.5 by examining the timing residuals, timing models, and noise model components. There is a remarkable level of agreement across all metrics considered. Our best-timed pulsars produce encouragingly similar results to those from NG12.5. In certain cases, such as high-DM pulsars with profile broadening, or sources that are weak and scintillating, wideband timing techniques prove to be beneficial, leading to more precise timing model parameters by 10-15%. The high-precision, multi-band measurements of several pulsars indicate frequency-dependent DMs. Compared to the narrowband analysis in NG12.5, the TOA volume is reduced by a factor of 33, which may ultimately facilitate computational speed-ups for complex pulsar timing array analyses. This first wideband pulsar timing data set is a stepping stone, and its consistent results with NG12.5 assure us that such data sets are appropriate for gravitational wave analyses., Comment: 62 pages, 55 figures, 5 tables, 3 appendices. Data available at http://nanograv.org/data/ and via DOI 10.5281/zenodo.4312887

We present time-of-arrival (TOA) measurements and timing models of 47 millisecond pulsars (MSPs) observed from 2004 to 2017 at the Arecibo Observatory and the Green Bank Telescope by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). The observing cadence was three to four weeks for most pulsars over most of this time span, with weekly observations of six sources. These data were collected for use in low-frequency gravitational wave searches and for other astrophysical purposes. We detail our observational methods and present a set of TOA measurements, based on "narrowband" analysis, in which many TOAs are calculated within narrow radio-frequency bands for data collected simultaneously across a wide bandwidth. A separate set of "wideband" TOAs will be presented in a companion paper. We detail a number of methodological changes compared to our previous work which yield a cleaner and more uniformly processed data set. Our timing models include several new astrometric and binary pulsar measurements, including previously unpublished values for the parallaxes of PSRs J1832-0836 and J2322+2057, the secular derivatives of the projected semi-major orbital axes of PSRs J0613-0200 and J2229+2643, and the first detection of the Shapiro delay in PSR J2145-0750. We report detectable levels of red noise in the time series for 14 pulsars. As a check on timing model reliability, we investigate the stability of astrometric parameters across data sets of different lengths. We report flux density measurements for all pulsars observed. Searches for stochastic and continuous gravitational waves using these data will be subjects of forthcoming publications., Comment: 54 pages, 52 figures, 7 tables, 1 appendix. Data are available at http://nanograv.org/data/ and via the DOI 10.5281/zenodo.4312297

We search for an isotropic stochastic gravitational-wave background (GWB) in the $12.5$-year pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves. Our analysis finds strong evidence of a stochastic process, modeled as a power-law, with common amplitude and spectral slope across pulsars. The Bayesian posterior of the amplitude for an $f^{-2/3}$ power-law spectrum, expressed as the characteristic GW strain, has median $1.92 \times 10^{-15}$ and $5\%$--$95\%$ quantiles of $1.37$--$2.67 \times 10^{-15}$ at a reference frequency of $f_\mathrm{yr} = 1 ~\mathrm{yr}^{-1}$. The Bayes factor in favor of the common-spectrum process versus independent red-noise processes in each pulsar exceeds $10,000$. However, we find no statistically significant evidence that this process has quadrupolar spatial correlations, which we would consider necessary to claim a GWB detection consistent with general relativity. We find that the process has neither monopolar nor dipolar correlations, which may arise from, for example, reference clock or solar system ephemeris systematics, respectively. The amplitude posterior has significant support above previously reported upper limits; we explain this in terms of the Bayesian priors assumed for intrinsic pulsar red noise. We examine potential implications for the supermassive black hole binary population under the hypothesis that the signal is indeed astrophysical in nature., Comment: 25 pages, 14 figures, 5 tables, 3 appendices. Published in The Astrophysical Journal Letters. Please send any comments/questions to Joseph Simon (joe.simon@nanograv.org). Jupyter notebook tutorials and some MCMC chain files are available at https://github.com/nanograv/12p5yr_stochastic_analysis

Searches for gravitational waves produced by coalescing black hole binaries with total masses $\gtrsim25\,$M$_\odot$ use matched filtering with templates of short duration. Non-Gaussian noise bursts in gravitational wave detector data can mimic short signals and limit the sensitivity of these searches. Previous searches have relied on empirically designed statistics incorporating signal-to-noise ratio and signal-based vetoes to separate gravitational wave candidates from noise candidates. We report on sensitivity improvements achieved using a multivariate candidate ranking statistic derived from a supervised machine learning algorithm. We apply the random forest of bagged decision trees technique to two separate searches in the high mass $\left( \gtrsim25\,\mathrm{M}_\odot \right)$ parameter space. For a search which is sensitive to gravitational waves from the inspiral, merger, and ringdown (IMR) of binary black holes with total mass between $25\,$M$_\odot$ and $100\,$M$_\odot$, we find sensitive volume improvements as high as $70_{\pm 13}-109_{\pm 11}$\% when compared to the previously used ranking statistic. For a ringdown-only search which is sensitive to gravitational waves from the resultant perturbed intermediate mass black hole with mass roughly between $10\,$M$_\odot$ and $600\,$M$_\odot$, we find sensitive volume improvements as high as $61_{\pm 4}-241_{\pm 12}$\% when compared to the previously used ranking statistic. We also report how sensitivity improvements can differ depending on mass regime, mass ratio, and available data quality information. Finally, we describe the techniques used to tune and train the random forest classifier that can be generalized to its use in other searches for gravitational waves.

We have explored the role of electrokinetics in the spontaneous motion of platinum-gold nanorods suspended in hydrogen peroxide (H2O2) solutions that may arise from the bimetallic electrochemical decomposition of H2O2. The electrochemical decomposition pathway was confirmed by measuring the steady-state short-circuit current between platinum and gold interdigitated microelectrodes (IMEs) in the presence of H2O2. The resulting ion flux from platinum to gold implies an electric field in the surrounding solution that can be estimated from Ohm's Law. This catalytically generated electric field could in principle bring about electrokinetic effects that scale with the Helmholtz-Smoluchowski equation. Accordingly, we observed a linear relationship between bimetallic rod speed and the resistivity of the bulk solution. Previous observations relating a decrease in speed to an increase in ethanol concentration can be explained in terms of a decrease in current density caused by the presence of ethanol. Furthermore, we found that the catalytically generated electric field in the solution near a Pt/Au IME in the presence of H2O2 is capable of inducing electroosmotic fluid flow that can be switched on and off externally. We demonstrate that the velocity of the fluid flow in the plane of the IME is a function of the electric field, whether catalytically generated or applied from an external current source. Our findings indicate that the motion of PtAu nanorods in H2O2 is primarily due to a catalytically induced electrokinetic phenomenon and that other mechanisms, such as those related to interfacial tension gradients, play at best a minor role.

One of Roberts' key contributions was his work demonstrat- ing the applicability of several ecological rules to human populations (Roberts (1953) Am. J. Phys. Anthropol. 11:533-558; (1978) Climate and Human Variability, 2nd ed., Menlo Park, CA: Cummings). His finding that average body weight systematically covaries with mean annual temperature was widely taken as confirmation of Bergmann's rule for humans. More recently his findings on weight and temperature have been extended and confirmed (Ruff (1994) Yrbk. Phys. Anthropol. 37:65-407; Katzmarzyk and Leonard (1995) Hum Biol Council Program Abstracts 132) although the strength of the association may be decreasing when considering more recent surveys (Katz- marzyk and Leonard (1995)). Roberts noted in 1953 that Oceanic populations may be somewhat of an exception to Bergmann's rule, and we propose that Neel's ((1962) Am. J. Hum. Genet. 14:353-362) thrifty genotype model may account for some of the deviation from predicted weights among these populations. We provide an updated version of the thrifty genotype model, suggesting that selection for energetic efficiency may have occurred for some Oceanic populations during the voyaging to and settlement of their island homes. Under conditions of modernization the thrifty genotype may be manifesting as high rates of obesity and NIDDM among Polynesians and Micronesians. First, using measurements of adult male weight from 19 Oceanic populations, we demonstrate the extreme nature of their deviation from predicted weight based on Roberts' regression of weight on mean annual temperature. Next, we regress the deviations from predicted weight on NIDDM prevalence for these 19 populations, producing a highly significant regression (R 2 5 0.46; P , 0.001), consistent with expectations if the thrifty genotype is responsible for the high weights. Am J Phys Anthropol 104:201-210, 1997. r 1997 Wiley-Liss, Inc.

Attempts to understand the causes for phenotypical differences in the biology and behavior of human populations have tended to focus alternatively on genetic, cultural, and natural environmental variables. The relative narrowness of focus in these studies often impedes the development of research design appropriate to the hypothesis and the process of reaching reasonable conclusions. Past research on native high-altitude populations is used first to illustrate the deficiencies of research based on single variables and errors which can occur in conclusions about causal factors when potential genetic contributions are excluded. Analyses of blood pressure data from Samoan modernization studies are used to illustrate the complexity of determining causality in the development of a pathological condition. The need for better qualified cross-cultural measures is emphasized. Am. J. Hum. Biol. 9:93-101 © 1997 Wiley-Liss, Inc.

Attempts to understand the causes for phenotypical differences in the biology and behavior of human populations have tended to focus alternatively on genetic, cultural, and natural environmental variables. The relative narrowness of focus in these studies often impedes the development of research design appropriate to the hypothesis and the process of reaching reasonable conclusions. Past research on native high-altitude populations is used first to illustrate the deficiencies of research based on single variables and errors which can occur in conclusions about causal factors when potential genetic contributions are excluded. Analyses of blood pressure data from Samoan modernization studies are used to illustrate the complexity of determining causality in the development of a pathological condition. The need for better qualified cross-cultural measures is emphasized. Am. J. Hum. Biol. 9:93-101 © 1997 Wiley-Liss, Inc.

This article is a memoir of anthropologist Paul Baker's professional life. The introduction notes that the field of anthropology was altered by the impact of World War II when physical anthropologists provided vital information to the military. After the war, the GI bill supported the undergraduate and graduate studies of veterans, including Baker. After describing his academic training at the University of New Mexico and Harvard, Baker details his research training and field work in the desert for the US Climatic Research Laboratory and his work identifying the dead in Japan for the Quartermaster unit. Baker then traces his academic career at the Pennsylvania State University during which he directed two multidisciplinary research efforts for the International Biological Programme, one that sought to understand human adaptability at high altitude in Peru and another that studied migration and modernization in Samoa. Baker's last administrative positions were as staff consultant to the Man and the Biosphere (MAB) program and as chair of the US MAB committee. Baker retired from academic life at age 60 in 1987 and has devoted his time to reading and to helping organize professional associations in anthropology, especially those devoted to furthering internationally organized scientific efforts. Baker concludes this memoir by acknowledging the growth and development of the discipline of human population biology.

Urinary catecholamine excretion rates have been used as a cross-culturally valid measure of generalized stress. The purposes of this paper are to examine group differences in catecholamine excretion rates in three Samoan groups who differ in degree of modernization and to compare these findings to rates of norepinephrine and epinephrine excretion in other populations. In 1986-1987, 24-hr urine samples were collected from 18-37-year-old Samoans; 46 rural Western Samoan villagers, 53 American Samoans, and 49 Samoans residing in Honolulu. The results show that norepinephrine excretion is significantly higher in more modernized Samoan groups (P less than 0.05), while epinephrine excretion is not significantly different in the three groups. The higher norepinephrine excretion rate in the more modernized Samoan groups may be related to differences in relative work load associated with changes in body weight, work capacity, and work patterns which accompany modernization. Samoan epinephrine excretion rates are relatively high compared to the results of other population studies, while norepinephrine excretion in three Samoan samples ranged from among the lowest rates observed worldwide to among the highest.

Human Adaptability: Past, Present, and Future. Stanley J. Ulijaszek and Rebecca A. Huss-Ashmore. eds. New York: Oxford University Press, 1997.326 pp.

In a Stirling-award winning article, Ralph Bolton offered a psychophysiological explanation for the notorious levels of aggression among the "Qolla" (Quechua and Aymara) Indians of the Peruvian altiplano. The long-standing anthropological characterization of these peasants as pathologically aggressive was supported by Bolton's finding that the community of Incawatana had one of the highest murder rates on record. He hypothesized that mild hypoglycemia (low blood sugar) is the primary cause of such aggression. When a glucose tolerance test was given to 66 Incawatana subjects 55.5% were diagnosed as hypoglycemic, and there was indeed a statistically significant correlation between aggression, as measured by informant ratings, and a drop in blood glucose below fasting level of 10 to 25 mg per 100 ml of whole blood. However, studies by recent researchers strongly suggest that the characterization of the Qolla as highly aggressive is merely a pseudo-scientific stereotype; homicide rates for other Qolla communi...

Currently available models used for predicting human caloric requirements do not reflect the great variability in activity patterns observed among populations, and are insensitive to important anthropometric, demographic, and environmental variables. They are thus inadequate for application to many populations and problems of anthropological interest. We present a model for determining caloric requirements which more accurately accommodates the effects of variation in activity and in anthropometries on individual needs, and which predicts population requirements based on individual needs and demographic parameters. The model is tested on four populations (the Andean community of Nunoa, Peru, the Dobe !Kung of Botswana, and two New Guinean villages) and is found to provide consistently better estimates of caloric requirements than are generated by the Food and Agriculture/World Health Organization's model. This model should be useful to anthropologists and human ecologists concerned with problems involving human energy consumption, such as the efficiency of subsistence strategies, optimum family composition, or certain consequences of increased labor migration or technological change.

SummaryModernization and migration have biological as well as social effects on people. In this study, 2657 Samoan adults from Western Samoa, American Samoa and Hawaii were surveyed in an attempt to examine the relationships between modernization, migration and obesity. The Samoan men showed an increase in the frequency of obesity with increasing modernity of residence or occupation. While the women in American Samoa had the highest frequency of obesity of any subsample, Samoan women also demonstrated a pattern of higher adiposity in more modern jobs. Young women tended to show a negative relationship between obesity frequency and education, with college-educated women having the lowest average levels of adiposity. Time since migration to Hawaii was not found to exert a major effect on frequency of obesity.

A health questionnaire was given to three populations of Peruvians: low-altitude sedentes, low-altitude migrants and high-altitude migrants, all of whom resided in the same low-altitude valley. Estimates of health were computed for each individual by summing the number of symptoms reported in the questionnaire. In general, male and female high-altitude migrants reported more symptoms than low-altitude sedentes. Female low-altitude migrants also reported more symptoms than did female sedentes, while there were virtually no differences between male low-altitude migrants and sedentes. Differences in numbers of days ill and the inability to work due to illness paralleled the differences in reported symptoms. It is suggested that the population differences are primarily the result of changes in the physical and cultural environments which are related to migration: high-altitude migrants being more affected than low-altitude migrants because of the greater degree of change they experience in migrating from high to low altitude. Specifically male high-altitude migrants reported significantly more gastrointestinal symptoms while both males and females reported significantly greater numbers of respiratory symptoms. Although the source of the former difference is unclear, it is felt that the increase in respiratory symptoms is a result of biological adaptations to high altitude which are no longer functional at low altitude.

Cultural behavior, when viewed as an extrasomatic adaptation for humans, alters previous interpretations of taboos as harmless placations of the supernatural. If the adaptive premise is true, then one may expect to find that taboos either have, or at one time had, an adaptive significance. This paper examines the salt and salt-containing-food taboos that were prevalent among the Indians in the southeastern United States during the early historic period. The analysis indicates that salt taboos existed as a means of regulating dietary sodium intake at times when such control was crucial for the restoration of biological equilibrium. Salt taboos occurred when a low-sodium diet would be physically advantageous: during menstruation, pregnancy, some diseases, and mourning. Prohibitions aloso applied where the behavior resulting from the disrupted system was considered desirable by the cultures concerned: during puberty rites and warfare.

Relationships among age at marriage, age at migration, education, ideal number of children, years since marriage and migration, and number of live births in Samoa and Hawaii are analyzed in a cross‐sectional sample of Samoan women currently living in Hawaii. Migration from Samoa to Oahu, Hawaii leads to a shift from a relatively traditional environment to a modern, urbanized setting. The timing of this migration, as well as the characteristics of the female migrants, influences the way in which the migration process affects fertility. Path analysis is used to quantify the interrelationships among the variables for a model which includes the determinants of the number of live births to a female migrant, both before and after migration. Quantification of the model provides preliminary support for the hypothesis that as exposure to a modern, urbanized environment increases, fertility decreases.

Familial correlations of blood pressure corrected for age, sex, and body weight are described in, and compared among, four Samoan samples which differ in exposure to modern life. An initial assessment of the genetic effects on blood pressure variation is performed in the most traditional sample. The juvenile sibling correlation of systolic pressure increases with modernization, whereas the adult sibling systolic correlation decreases with modernization. It is suggested that there is an increased interfamilial and decreased intrafamilial variation in environment as modernization increases. The preliminary estimate of the additive genetic effects, .25, is discussed in terms of the environmental variation in traditional life.

ANTHROPOLOGY is one of the few scientific disciplines which has traditionally studied man from multiple perspectives. Anthropologists have studied him in time and spatial distribution, in biology and social structure, with the goal of providing an integrated theoretical structure for the understanding of our unusual species. Such an effort at breadth is obviously difficult in an era of multiplying specialties, each of which contains an increasing amount of information. There exists no absolute criterion against which we can measure anthropologists' success in this endeavor, but it has become apparent to many that physical anthropology with its concern for human biology has drifted away from the other major aspects of the field. This division of the field may in great part be ascribed to the exclusion of human biology from anthropology's unifying concept of "culture." The concept of culture, as defined by some, almost precludes the biology of man from a significant role in his behavior. In a recent article in the Scientific American, Marshall Sahlins (1960) stated, "Human social life is culturally, not biologically, determined." He later said, "Yet the remarkable aspect of culture's usurpation of the evolutionary task from biology was that in so doing it was forced to oppose man's primate nature on many fronts and to subdue it." If indeed culture did subdue man's biological inheritance then there would be little utility in considering human biology when studying human behavior, and we could relegate physical anthropology to a study of man's interesting past and his present physical structure. However, it is apparent that man has not yet freed himself from the biological world which begat him. Some of his behavior, such as conception, birth, and death, are still within the biological framework of his mammalian order. The child psychologists remind us that the age

Thirty-one men of widely varying body fat content were exposed to air at 15.2 C for 2 hr. Rectal and skin temperatures and metabolic rates were measured at 10, 40, and 80 min and at the end of the 2 hr. Shivering was rated on a five-interval scale. Under these conditions thick subcutaneous fat provided insulation as indicated by lower skin temperatures, less shivering, and lower oxygen consumption in the fatter men. The findings rule out simple relationships between measured temperatures and shivering, leading to other possibilities and approaches to the study of shivering. Submitted on October 3, 1960

After a period of passive observation of his own phylogenesis, Homo sapiens has begun to take an active role in the development of his species. Having progressed through the stages of treatment and prophylaxis of disease, he will eventually become capable of directing human development. This stage is of concern to physical anthropology, one of the branches of biomedical science. It is also of particular interest to cultural anthropology, because man as a biological entity is the basis of social phenomena. This paper deals with the scientific basis for the control of the physical development of individuals and populations. This problem is of extreme importance in view of the serious responsibility which must be assumed by those who will direct the physical development of the human species. Some of the problems dealt with here are (1) basic concepts in physical development, among them (a) aspects of physical development-growth, differentiation and maturation, kinetics, and dynamics; (b) averageness, normali...

It is generally recognized that there exists currently a strong trend toward the "fractionation" of anthropology and the "absorption" of its several subdivisions into other disciplines. On the other hand, if we are striving for a balanced perspective on present-day anthropology we should not ignore a concurrent movement toward the integration of biological and sociocultural anthropology into a unified science. In this paper an attempt is made to appraise certain aspects of this latter trend and to suggest some steps which may be taken immediately by anthropologists to accelerate the development of a unified science of mankind. The long-standing conceptual dichotomy in the study of man has become, in the United States at least, an institutionalized vested interest. This situation, together with resistance to such new orientations as population thinking, bioecological thinking, and neuropsychiatric thinking, are obstacles to unification at both the theoretical and the methodological levels. On the other han...

A common definition of the fi eld of biological anthrop ology i s that it con­ cern s the description, caus es, and consequences of v ari ability in human bio­ logical characteristics. As such i t is somewhat surprising that so little atten­ tion has been dev oted to suc h an i mportant biologic al parameter as human demog raphy. In the ear ly development of anthropology there was a brief i nterest i n demography as attempts were made to discover whether some men had found a way to i ncreas e longevity. These myths persist with reports of great age in the USSR and the South Americ an Andean region. Anthropologists were also c urious about the longevity of our ancestors so that both historic al and skele­ tal studies of mortality were i n v ogue. At the opposite end of the life cycle considerable effort was expended on the s tudy of sex rati os at bi rth and the nature of seasonality i n bir th. Despite these early i nterests the field of demog­ r aphy was not pursued with any depth until recently. At the moment i nterest i n demog raphic data i s very much on the rise and shows no s ign of being near i ts peak. The reasons for the i ncreased inter­ est can be catalogued into three discrete developments of the 1960s. Firs t, the development of extensive research programs on the nonhuman primate i n his natural environment has produced a new body of descriptive data. Second, the develop ment of human p opulation genetics from the general synthetic theory of evolution has indicated the need for new types of demographic data on nonwestern populations . Finally , the strong interest in a subject area best c alled human ecology has suggested new ways in which we can understand the immediate causes and effects of population differences i n demographic c haracteristics. I n this paper we will attempt to highlight the current status of research i n these topics ev en though much of the subject matter has been

The skin reflectance characteristics of a group of Quechua Indians have been described with an emphasis upon the effects of varying degrees of hybridization, sex and age. This group of Peruvian Indians occupied a reflectance range common to that of all other reported groups of South American Indians. Miscegenation with European Whites had a statistically significant although small influence upon skin color. In general males were consistently darker than females on the three body sites measured. A significant darkening on unexposed body areas occurred in both sexes during early adolescence which may have been caused by the high activity level of the pituitary gland at that stage of the growth cycle.

This paper presents a quantitative description of the volume required to use common hand tools. The volume described, termed the “space envelope”, is for the tool using hand of right-handed subjects. The data were collected on six individuals who had hands at or above the 95th percentile of the military population in length and breadth. The data were obtained by use of a photographic process employing time exposures for each action. This technique provided data comparable to that provided by movie techniques but at a lower cost. The implications of the data for maintenance requirements are also discussed.

Within the general framework of evolutionary and adaptation theory there are a number of general principles that will assist in the understanding of the biological effects of migration. 1st populations with relatively stable social and subsistence and which have been long resident in a given area have adapted in their biology population structure and sociocultural system to this area and its environment. All biological adaptive patterns have genetic bases; however some are fairly specific and easily identifiable from their phenotypic expression while others are more plastic or flexible and are expressed more broadly depending on environmental circumstances. Several hypotheses have been suggested to define further the biological effects of migration: 1) The more rapid and dramatic changes will produce greater stress as manifested by illness loss of biological fitness and declines in sociocultural integration than will gradual and minor changes. 2) Adults particularly the elderly will suffer more from environmental change than will children. This is based on the knowledge that some adaptations require development during the period of child and adolescent growth. 3) Effects of environmental change on health and state of adaptation will be most acute immediately after a move. Adjustments will occur as exposure to the new environment increases. There is some evidence to support each of these 3 hypotheses yet they are not quite at the level of general principles. This literature review looks at existing studies that consider the biological and adaptive attributes of migrants which are important for at least 2 reasons. 1st at the level of science and basic knowledge migrant people serve as ideal natural experiments in which the effects of environmental change on human populations can be investigated within the theoretical framework of adaptation. Secondly there are real risks to human health and biological fitness associated with the process of migration and these risks should be known and understood. This latter applied basis for studies of migrants is especially important now since present migration rates are greater than at any other time in the past.

Comparisons of 13 lifestyle characteristics and the rates of urinary catecholamine excretion during typical morning activity are examined among four groups of young Samoan men in Western Samoa. The groups include 28 manual laborers, 33 sedentary workers, and 31 college students from the urban area of Apia, and 31 rural agriculturalists. Associations between the lifestyle variables and catecholamine excretion rates are also investigated in the total sample (N = 123) using correlations and multiple stepwise regression techniques. Results of the lifestyle characteristic comparisons show that the villagers have greater life satisfaction, emotional stability, agreement with Samoan customs, and familial responsibility (P less than 0.05). The catecholamine comparisons show that the villagers have lower rates of epinephrine and norepinephrine excretion than any of the Apia groups (P less than 0.05 and P less than 0.005 respectively). The regressions indicate that diet, activity, day of specimen collection and the overall lifestyle and ecological differences between the village and Apia are associated with 25 and 31% of the variation in the rates of epinephrine and norepinephrine excretion respectively. These results suggest that both psychological and habitual behavioral differences contribute to the catecholamine variation of the men in this study, and that these differences are related to the degree of participation in Western lifestyles.

In order to examine the relationship between hypoxia and reduced fertility of high Andean populations, a sample of 241 females living in the low-altitude Tambo Valley of Peru was studied. 63 of the subjects were born in the low-altitude valley, 121 were migrants from high altitudes, and 57 were migrants born in low altitudes. The rate of abortion was low among high-altitude subjects before they migrated, but became greater after migrating. It was found that the high-altitude populations had almost twice as long parity intervals than the low-altitude populations. Compared to migrants born at low altitudes, the high-altitude-born subjects who migrated to low altitudes had higher fertility rates. The results of the study are consistent with the hypothesis that high altitudes, through anoxia, have a lowering effect on fertility. Of the several possible explanations which might account for the increase in fertility of downward migrants on migration from high to low altitude (migration, socioeconomic factors, acculturation, seasonal male emigration from high altitude, and removal of hypoxia stress), altitude appears to be the most significant.

In present day research in human biology, the validity of the concept of biological race rests on its utility as a research tool. The methodology of this research into human biological variability is a multidimensional application of the comparative method, utilizing, as one dimension, genetic distance. The body of this paper suggests two generalizing principles for the establishment of genetic distance. Genetic distance may occur due to physical or temporal isolation or in conjunction with environmental differences. A brief analysis of the fifteenth century human populations examines the relationship between these principles and presently used racial taxonomic systems. It is concluded that race may be defined operationally as a rough measure of genetic distance in human populations and as such may function as an informational construct in the multidisciplinary area of research in human biology.

Data on physical growth were obtained for a sample of 1202 Quechua subjects, aged 2 to 35 years from the district of Nunoa, Puno, located in the southern highlands (altitude 4000–5500m) of Peru. These data were supplemented by a three-year longitudinal study of 300 subjects, aged 1 to 22 years. The patterns of physical growth of members of the indigenous population of Nunoa are characterized by (1) late sexual dimorphism, (2) slow and prolonged growth in body size, (3) late and poorly defined adolescent stature spurt in both males and females, and (4) accelerated development in chest size. The socio-economic factors associated with urban-rural and altitude differences appear to be reflected in greater deposition of subcutaneous fat and increased weight but do not seem to influence the development of stature. We suggest the pattern of growth of this population is related to the hypoxic effects of high altitude, and/or reflects a genetic adaptation to such stress. The anthropometric and physiological studies conducted during this and previous studies and the comparative data from Peruvian populations situated at lower altitudes document the specific adaptive response of the chest wall to the hypoxic effects of high altitude.

In order to determine the possible role of body characteristics in mans ability to adapt and acclimatize to high altitude cold the physical characteristics of four groups of individuals were correlated to their body temperature responses when exposed to an ambient temperature of 14 degrees C. for two hours at an altitude of 3760 meters. The body characteristics chosen for analysis were, age, standing height, sitting height, weight, % body fat, fat free weight and sum of skinfold. The four groups were U.S. Whites, University of Cuzco White and Indian students and native Indian villagers. The results showed significant association between body characteristics and body temperatures in all groups. Fat acted as insulation in all groups and fat free weight had very significant positive effects on total body heat content. The total body heat content of native Indian villagers was more significantly affected by age than in other groups and fat-free weight in this group had a strong effect on peripheral body temperatures. The results agree with the suggestion made in the previous progress report that native Indian villagers have a higher metabolic response to cold stress.