bluuebunny/crossref_metadata_2025 huggingface dataset:
Body size and fatness of free‐living baboons reflect food availability and activity levels
Authors: Altmann Jeanne , Schoeller Dale , Altmann Stuart A. , Muruthi Philip , Sapolsky Robert M.
Published: June 2005

We used morphometric techniques and isotope‐labeled water to investigate the influence of abundant, accessible food and resultant low activity levels on body size and fatness in free‐living adolescent and adult baboons as compared to animals in the same population that experienced more typical, wild‐feeding conditions. Females that had access to abundant food from a nearby garbage dump averaged 16.7 kg body mass, 50% more than their wild‐feeding counterparts in adjacent home ranges. Little of the difference was due to lean mass: the animals with an accessible abundance of food averaged 23.2% body fat in contrast to 1.9% for the wild‐feeding animals. Significant differences between feeding conditions were found for all measured skinfolds and for upper arm circumference but not for linear measurements. Differences between feeding conditions were less for males than for females, perhaps reflecting persistent effects of nutritional conditions during the first eight years of life before dispersal from the group of birth. The difference in fatness between feeding conditions was similar to the difference between humans with frank obesity and those that are considered lean, but in both cases the percentages of body fat in the baboons were considerably less than those observed in humans. In levels of fatness, the relatively sedentary animals resembled their counterparts in group‐housed captive conditions. © 1993 Wiley‐Liss, Inc.
Testis size, epididymis weight, and sperm competition in rhesus macaques
Authors: Bercovitch Fred B. , Rodriguez Jose F.
Published: June 2005

The intensity of sperm competition is often measured using the gonadosomatic index (testes/body weight). But sperm competition could be mediated more by size of the epididymis than by size of the testicles, and little information is available on the relationship between testicular and epididymal size. We found that both organs were positively correlated in size among male rhesus macaques. Body weight accounted for over 70% of the variance in testicle size and volumetric estimates of testicle size accurately reflected testicle weight. We conclude that methods for ascertaining testicle size are accurate, but the covariation in size between testicles and epididymis will hamper understanding of the physiological mechanisms involved in sperm competition in primates. © 1993 Wiley‐Liss, Inc.
Further hormonal suppression of eldest daughter cotton‐top tamarins following birth of infants
Authors: Snowdon Charles T. , Ziegler Toni E. , Widowski Tina M.
Published: June 2005

Reproductive suppression of females is found throughout the Callitrichids. However, in many species some evidence of ovarian activity is observed in subordinate females. Subordinate cotton‐top tamarin females in our colony have never been observed to ovulate in the presence of a reproductive female. However, ovarian follicular development does occur, and measurable levels of urinary estrogen and luteinizing hormone are frequently found in subordinate females. We studied 11 female tamarins living in family groups with a reproductive female. Each of the 8 eldest daughters had measurable urinary estrogen and LH levels and showed a reduction of hormonal levels when new infants were born. The 3 younger daughters showed barely detectable hormonal levels that did not change. Following the birth of infants the eldest daughters scent marked less frequently, increased time in contact with and grooming group members other than the mother, but they were more often targets of aggression than immediately prior to infant births. The eldest daughters were somewhat less involved in care of new infants than expected, although they spent much time in proximity to those carrying the infants. These results suggest that the further reduction of hormonal levels in subordinate females after the birth of infants may function to prevent these females from competing with mothers during the post‐partum estrus rather than recruiting the eldest daughters as helpers for infant care. © 1993 Wiley‐Liss, Inc.
Kinship, association, and social relationships in rhesus monkeys (Macaca mulatta)
Authors: Bernstein Irwin S. , Judge Peter G. , Ruehlmann Thomas E.
Published: June 2005

Data on social interactions with matrilineal kin were collected from two groups of rhesus monkeys for 6 years. All behavioral states, including time within one meter of another, involved kin more often than would be expected by chance. Significant associations were also found between kinship and the frequencies of various forms of agonistic as well as affiliative acts. Frequency of social interaction, however, was not a simple function of time in proximity. Although animals spent more time with kin than nonkin they had more aggressive interactions with kin. Moreover, aggression was biased toward the more serious forms of expression in interactions with kin. Time spent in association was neither predictive of the rate of aggressive interaction nor reduced by high rates of aggressive interaction. Rather than association time influencing rates of interaction, association time may be the consequence of a history of aggressive and affiliative exchanges. Preferential association and high rates of aggressive interaction with kin may be possible due to the existence of compensating social mechanisms nullifying the negative influence of specific aggressive encounters. © 1993 Wiley‐Liss, Inc.
Circulating and excreted hormones during the ovarian cycle in the cotton‐top tamarin, Saguinus oedipus
Authors: Ziegler Toni E. , Wittwer Daniel J. , Snowdon Charles T.
Published: June 2005

Five parous, cycling cotton‐top tamarin females were used to compare circulating and urinary profiles of the major reproductive hormones during the ovarian cycle. Blood samples were collected on unanesthetized, hand restrained females three times per week for 25 days and first morning void urine was collected daily for 30–40 days including the serum sampling period. Serum and urine samples were analyzed for estrone, estradiol, and bioactive LH. Additionally, serum was analyzed for progesterone and urine for estrone conjugates (E1G) and immunoreactive LH. Both serum and urinary hormonal profiles revealed ovarian cyclicity in four females; the fifth one stopped cycling during the study. All hormones were referenced to the urinary immunoreactive LH peak. Urinary estrone conjugates followed similar profiles to serum progesterone. Progesterone levels increased two‐ to threefold on the day of the urinary immunoreactive LH peak. Peak levels of circulating bioactive LH occurred on the same day or the day preceding the urinary bioactive and immunoreactive LH peak for all four cycling females. Serum estradiol levels rose during the follicular phase and peaked prior to or on the day of the urinary LH peak while urinary estradiol levels did not rise until the day of the urinary LH peak. Serum and urinary estrone levels did not rise until the day of the urinary LH peak and remained high throughout the luteal phase. The measurement of urinary LH corresponded well with serum LH, establishing urinary LH as an important hormone for monitoring the ovulation in the tamarin. The highest circulating estradiol concentrations were found in the follicular phase of the cycle, but estradiol did not appear in urine during the follicular phase of the cycle. Elevated estrone levels occur during the luteal phase following the progesterone pattern, and therefore elevated urinary concentrations of estrone and estrone conjugates may be indicative of luteal function. © 1993 Wiley‐Liss, Inc.
Notes on the ecology of buffy saki monkeys (Pithecia albicans, Gray 1860): A canopy seed‐predator
Authors: Peres Carlos A.
Published: June 2005

Data on the ecology and diet of buffy sakis (Pithecia albicans) were obtained during a 20‐month study in an entirely undisturbed terra firme forest in the upper Urucu river, Amazonas, Brazil. Groups of 3–7 sakis found in a 900‐ha study plot used large home ranges (147–204 ha), which overlapped extensively with those of neighboring groups. Similar to other pitheciines, buffy sakis were primarily seed predators, relying heavily on young seeds of certain key plant families, such as the Sapotaceae and Leguminosae. Ripe fruits, ripe seeds, young leaves, flowers, and nectar were eaten to a lesser extent. Whether or not feeding, sakis spent most of their time in the canopy and subcanopy, a pattern similar to that of other southwestern Amazonian saki species, but sharply different from that of Guianan sakis (Pithecia pithecia), which use considerably lower levels of the forest. Comparisons are made between different Pithecia species to show whether and how P. albicans diverges ecologically from its congeners. © 1993 Wiley‐Liss, Inc.
Preliminary analysis of drinking from seawater sources by free‐ranging rhesus macaques (Macaca mulatta)
Authors: Lehman Shawn M. , Overdorff Deborah J. , Lessnau Robert G.
Published: June 2005

Rhesus macaques on Key Lois Island were observed drinking seawater that flowed into four holes they had excavated in the sand. Data were gathered to determine the salinity (TDS) and pH levels of the water and which animals were using the holes. Average TDS level (4,506.8 ± 1,750.8), but not pH (8.1 ± .30) level, of water from the holes differed from the surrounding seawater (TDS = 29,000, pH = 8.0). There were significant variations in TDS and pH levels of water between holes. A total of 249 drinking and 11 digging bouts were observed. Adult females drank and dug most often (46.9% of total bouts). Of the 260 total drinking and digging bouts, 76.1% (N = 198) were concentrated at one hole. This hole had the lowest average TDS level (3,714.2 ± 1,504.4) and one of the highest average pH levels (8.1 ± .29). Age/sex class differences in drinking bout frequencies may have been due to differential social status. We suggest that the holes were excavated to overcome a temporary shortage of provisioned water. © 1993 Wiley‐Liss, Inc.
Extended postpregnancy estrous cycles in fernale lion‐tailed macaques
Authors: Clarke A. S. , Harvey N. C. , Lindburg D. G.
Published: June 2005

Past studies of female primate reproduction have focused on regularly cycling females, and thus the reproductive characteristics of females in other reproductive states (e.g., pregnant, or lactating) have rarely been investigated. In this study, data were collected on estrous swellings and sexual and proceptive behavior in six female lion‐tailed macaques during recovery from lactational amenorrhea for the first three to five postpregnancy cycles. For these females, the length of the first lactational recovery swelling cycle averaged 81 days, nearly three times the length of cycles exhibited by nonparturient, isosexually housed females Actual swelling durations were also nearly three times the length of those seen in nonlactating females, and occupied a larger proportion of the cycle For most females, cycle duration and sexual and proceptive behavior declined progressively over successive cycles. The alpha female in each group accounted for the majority of copulations in the first three cycles, and this effect was pronounced in the first cycle. Extended postpregnancy cycles in this species may be related to female reproductive competition and /or a tactic to attract extra‐group males. © 1993 Wiley‐Liss, Inc.
Lethal territorial aggression in a white‐handed gibbon
Authors: Palombit Ryne A.
Published: June 2005

During an intergroup conflict an adult male white‐handed gibbon (Hylobates lar) from one group was attacked and wounded by the adult male of a neighboring group. The wounded male's calling behavior, general activity level, feeding, and participation in territorial defense declined dramatically in the days following the injury as he instead spent long periods resting and tending the wound. The normal and healthy appearance of this male prior to injury, the circumstances of the fight that caused the injury, the resultant deterioration in normal maintenance and social behavior, and finally the apparent infection of the wound by insect larvae all suggested that his disappearance 24 days later was the result of death due directly or indirectly to the wound he had suffered. The observations reported here suggest that the ritualization of territorial aggression in this species has not eliminated risks of serious injury and death. © 1993 Wiley‐Liss, Inc.
Social relationships of immigrant and resident female mountain gorillas, II: Relatedness, residence, and relationships between females
Authors: Watts David P.
Published: June 2005

Female transfer is common in mountain gorillas, but most adult females reside with female relatives for at least some of their lives. In four mountain gorilla social groups, co‐resident relatives had higher rates of affiliative interaction and lower rates of aggressive interaction, and were more tolerant of each other, than non‐relatives. These differences were greater for maternal than for paternal relatives. Non‐relatives typically had few affiliative interactions, but some (mostly but not entirely long‐term co‐residents) had friendly relationships. Females showed reciprocity in affiliative behavior. Long‐term residents in two groups maintained less tolerant relationships with more recent immigrants than with each other and than did most pairs of immigrants. The effects of relatedness and residence status on relationships may sometimes be complementary because both factors can lead to similar reproductive interests. A potential exists for some resemblance between female‐female social relationships in mountain gorillas and those in female‐bonded primate species. However, even female relatives usually spend little time interacting socially with each other, and the benefits of relationships with males outweigh those of relationships with other females. © 1994 Wiley‐Liss, Inc.
Insights into ovarian function in wild muriqui monkeys (Brachyteles arachnoides)
Authors: Strier Karen B. , Ziegler Toni E.
Published: June 2005

Fecal samples were collected systematically during a 6‐week period, from 13 September‐24 October, 1990, from four nonlactating female muriquis (Brachyteles arachnoides) inhabiting an 800 ha forest at Fazenda Montes Claros in Minas Gerais, Brazil. All four females were experienced mothers; one had most recently given birth in June 1988; the other three had most recently given birth in August 1988. Fecal assays measuring progesterone, estradiol, and estrone indicated consistently low levels in the one female who had given birth in June 1988 and in two of the three females who had given birth in August 1988. Elevated steroid levels did, however, appear in fecal samples from the fourth female on day 15 of the collection period. Steroid levels subsequently dropped and then began to rise again during what appeared to be a second cycle. The cycling female was the only one of the four females examined observed to copulate during the collection period. These preliminary data indicate that nonlactating female muriquis do not cycle year‐round, resumption of cycling is not tightly synchronized among females even when their prior parturitions were tightly synchronized, and resumed sexual activity appears to be associated with resumed cycling. © 1994 Wiley‐Liss, Inc.
Infant abuse associated with psychosocial stress in a group‐living pigtail macaque (Macaca nemestrina) Mother
Authors: Maestripieri Dario
Published: June 2005

This study reports a case of infant abuse by a pigtail macaque mother living in a captive social group. Patterns of abusive behavior appeared three weeks after the birth of the infant and were in strict temporal as sociation with the repeated kidnapping and severe harassment of the infant by the alpha‐female in the group. Before and after the period of social stress, the mother exhibited proper caregiving behavior towards her infant. The analysis of the abusive mother's style of interaction with her infant relative to three control mothers indicated that she was an extremely permissive mother. It is argued that the mother's failure to adapt her mothering style to better protect her infant during the period of repeated kidnappings and the resulting lack of control over the situation may be the mechanism by which stress precipitated infant abuse. © 1994 Wiley‐Liss, Inc.
Twinning in a colony of vervet monkeys (Cercopithecus aethiops sabaeus)
Authors: Pollack Deborah B. , Raleigh Michael J.
Published: June 2005

From 1975 through 1991, three sets of twins were born from a total of 693 live and stillborn births (0.43%) at the UCLA/Sepulveda Veterans Administration Medical Center Nonhuman Primate Research Laboratory, CA. None of the twin's mothers were related. Positive patrilineal relationships have not been established; however, a brother (not a twin) of the first set of twins may have fathered the third set. All twins were born to multiparous females and, in each case, only one infant survived beyond 4 days. One set of twins was dizygotic; the genetic status of the others is unknown. © 1994 Wiley‐Liss, Inc.
Sex differences in compatibility of pair‐housed adult longtailed macaques
Authors: Crockett Carolyn M. , Bowers Charles L. , Bowden Douglas M. , Sackett Gene P.
Published: June 2005

This research was designed to evaluate the effects of same‐sex pair housing on the psychological well‐being of adult wild‐born longtailed macaques (Macaca fascicularis). We studied behavioral compatibility and stress as measured by urinary cortisol excretion in 15 pairs of each sex. Before they were housed together, the pairs were categorized by noncontact pairedpreference testing as preferred, nonpreferred, or randomly assigned partners. Every aspect of data analysis indicated that the success of pairing was strongly related to gender. Whereas 100% of female pairs were compatible, only eight of the 15 male pairs were still together after two weeks, and only five (33%) showed a degree of compatibility resembling that of females.

The psychological well‐being of virtually all females seemed to be improved during the physical contact paired‐housing conditions; they spent more than one‐third of the day engaged in social grooming. Paired adult males had much lower interaction rates than adult females. On average, males were initially somewhat stressed by the introduction to a cagemate as indicated by increased urinary cortisol excretion.

The noncontact preference testing procedure was no more predictive of pair success than random assignment. For males, the presence of fighting combined with the absence of grooming during the first 90 min opportunity for physical contact (“introduction”) was associated with pair incompatibility, but not to a statistically significant extent.

For research protocols permitting social grouping of this species, the social contact requirement of the USDA Animal Welfare Rules usually can be met for adult females by pair housing. For males, pairing with other adult males often is unsuccessful; by our estimates, at least 20% of males cannot be pair‐housed with other males. These sex differences in response to same‐sex adults are consistent with the known socioecology of macaques. Further research is necessary to determine whether adult males have a lower need for social contact than females, or whether their needs are better met by other types of social contact. © 1994 Wiley‐Liss, Inc.
Rank‐related differences in cardiovascular function among wild baboons: Role of sensitivity to glucocorticoids
Authors: Sapolsky Robert M. , Share Lisa J.
Published: June 2005

In a population of wild baboons living in East Africa, we have observed endocrine differences among individuals as a function of dominance rank. Among these differences, we previously observed indirect evidence for dominant males being more. responsive to sympathetic catecholamines than were subordinate males. The present report tests this explicitly. Male baboons of known rank were anesthetized, and sympathetic and parasympathetic activity was pharmacologically inhibited. In experiment I, males were challenged with epinephrine; over a wide dose range, dominant males had the largest and fastest rises in systolic pressure, the greatest peak systolic pressure, and the most rapid recovery from the epinephrine challenge. Similar rank‐related differences in heart rate response to epinephrine also occurred. Experiment II showed that this phenomenon probably reflects rank‐related differences at both the heart and vasculature. As evidence, the same rank differences in systolic blood pressure responsiveness occurred when males were challenged with the alpha receptor agonist phenylephrine (which predominantly constricts systemic veins and arterioles), while the same rank differences in heart rate responses occurred following stimulation with the beta receptor agonist isoproterenol (which selectively works at the heart).

These data were obtained from animals stressed by anesthetization, known to cause considerable glucocorticoid secretion in this population. Such steroids are well known for their capacity to augment catecholamine action. In experiment III, we blocked endogenous glucocorticoid secretion with the steroidogenesis inhibitor metyrapone, and repeated the epinephrine challenge. Under these conditions, the rank differences in epinephrine responsiveness were eliminated. Thus, dominant males are not so much preferentially sensitive to catecholamine action, as much as to the potentiating effects of glucocorticoids upon such action. In agreement, we have observed previously that dominant males are also more sensitive to glucocorticoid negative feedback regulation. © Wiley‐Liss, Inc.
Dusk calling in barbary macaques (Macaca sylvanus): Demand for social shelter
Authors: Hammerschmidt Kurt , Ansorge Viveka , Fischer Julia , Todt Dietmar
Published: June 2005

Barbary macaques (Macaca sylvanus) show an increase in vocal activity at dusk. This investigation showed that these vocalizations were mainly produced by juveniles from six to 18 months of age, during their attempts to achieve body contact with their mothers, thereby building up a sleeping cluster. The “dusk calling” consisted of protracted sequences of variable vocal patterns which always ceased when the juvenile joined its preferred sleeping cluster. The length of the sequences corresponded to the time it took the juvenile to be accepted into a sleeping cluster. One‐year‐old juveniles exhibited the highest vocal activity. The similarity of the results obtained in two outdoor enclosures in France and of those in the field (Morocco) indicated that dusk calling is common to this species, and not a behavior unique to captive animals. © Wiley‐Liss, Inc.
Responses to natural and synthetic phee calls by common marmosets (Callithrix jacchus)
Authors: Norcross J. L. , Newman J. D. , Fitch W.
Published: June 2005

Captive adult common marmosets (Callithrix jacchus) produce whistlelike “phee” calls in two contexts: in the home cage, where phee calls may function as part of territorial marking behavior, and when separated from social companions, where phee calls may function to reunite conspecifics. Natural and synthesized calls representing the acoustic structure of male and female calls in each context were presented to adult marmosets in a playback paradigm. Marmosets demonstrated discriminative abilities according to the context of the call and the caller's sex. Vocal and behavioral responses indicated increased vigilance and territorial behavior, following playbacks of naturally produced calls as well as synthetic calls. All animals scanned more frequently following produced calls as well as synthetic calls. All animals scanned more frequently following natural home cage as well as isolation calls, but only increased contact behavior (trills) in response to home cage calls. The responses were dimorphic according to the sex of the caller, where adult males scanned more following male calls, and adult females were more aggressive following male and female calls. The differential behavioral responses to playbacks of marmoset phee calls suggest a biological relevance to subtle differences found in the acoustic parameters of the phee call. © 1994 Wiley‐Liss, Inc.

This article is a US Government work and, as such, in the public domain in the United States of America.
Infanticide among ringtailed lemurs (Lemur catta) at Berenty Reserve, Madagascar
Authors: Hood Laura C.
Published: June 2005

During an intertroop encounter, an infanticide was observed in a population of ringtailed lemurs (Lemur catta) at Berenty Reserve, Madagascar. The killer was a male that had not been previously observed to mate with any females in the infant's troop. This observation, combined with other observations of infanticidal behavior by males at Berenty Reserve and the Duke University Primate Center, is consistent with the hypothesis that infanticide is a reproductive tactic for some male ringtailed lemurs. © 1994 Wiley‐Liss, Inc.
Detection of pregnancy and monitoring patterns of uterine and fetal growth in the marmoset monkey (Callithrix jacchus) by real‐time ultrasonography
Authors: Oerke A.‐K. , Einspanier A. , Hodges J. K.
Published: June 2005

The purpose of this study was to evaluate the potential of real‐time ultrasonography for detecting and monitoring pregnancy in the common marmoset. Ultrasound was performed transabdominally on unsedated females using a 7.5 MHz linear or intraoperative sector probe. Pregnancies were timed using progesterone measurements in twice weekly blood samples to determine the day of ovulation. Eight pregnancies were examined three times a week until day 30, twice a week until day 80, and once a week until birth. Detection of pregnancy was possible on day 15, on average, by the appearance of a double endometrial echo indicating fluid accumulation in the uterus. The uterine lumen thus formed was first measurable on day 21 on average. Diameter of the pregnant uterus was significantly greater than that of the nonpregnant organ by day 38. Thereafter, the dimensions of uterus and uterine lumen showed a similar pattern of growth until day 75, when measurements became inaccurate due to increasing uterine pliability. Embryonic development was characterized by the initial expansion of the gestation sacs and the appearance of individual embryos by day 33. Detection of heart beat at approximately day 54 allowed confirmation of number and viability of the embryos. With the visualization of the skulls by day 82, it was possible to determine fetal position and to monitor fetal growth by measurement of the biparietal diameter. All pregnancies were of normal length (140–145 days) resulting in viable offspring. It can be concluded that ultrasonography is suitable for detecting and monitoring pregnancy in the marmoset monkey and as a non‐invasive method, has the potential for being routinely used in this and other species of Callitrichidae. © 1995 Wiley‐Liss, Inc.
Ontogeny and the evolution of adult body size dimorphism in apes
Authors: Leigh Steven R. , Shea Brian T.
Published: June 2005

This analysis investigates the ontogeny of body size dimorphism in apes. The processes that lead to adult body size dimorphism are illustrated and described. Potential covariation between ontogenetic processes and socioecological variables is evaluated. Mixed‐longitudinal growth data from 395 captive individuals (representing Hylobates lar [gibbon], Hylobates syndactylus [siamang], Pongo pygmaeus [orangutan], Gorilla gorilla [gorilla], Pan paniscus [pygmy chimpanzee], and Pan troglodytes [“common” chimpanzee]) form the basis of this study.

Results illustrate heterogeneity in the growth processes that produce ape dimorphism. Hylobatids show no sexual differentiation in body weight growth. Adult body size dimorphism in Pongo can be largely attributed to indeterminate male growth. Dimorphism in African apes is produced by two different ontogenetic processes. Both pygmy chimpanzees (Pan paniscus) and gorillas (Gorilla gorilla) become dimorphic primarily through bimaturism (sex differences in duration of growth). In contrast, sex differences in rate of growth account for the majority of dimorphism in common chimpanzees (Pan troglodytes).

Diversity in the ontogenetic pathways that produce adult body size dimorphism may be related to multiple evolutionary causes of dimorphism. The lack of sex differences in hylobatid growth is consistent with a monogamous social organization. Adult dimorphism in Pongo can be attributed to sexual selection for indeterminate male growth. Interpretation of dimorphism in African apes is complicated because factors that influence female ontogeny have a substantial effect on the resultant adult dimorphism. Sexual selection for prolonged male growth in gorillas may also increase bimaturism relative to common chimpanzees. Variation in female growth is hypothesized to covary with foraging adaptations and with differences in female competition that result from these foraging adaptations. Variation in male growth probably corresponds to variation in level of sexual selection. © 1995 Wiley‐Liss, Inc.
The archeology of modern human origins
Authors: Klein Richard G.
Published: June 2005

Two competing hypotheses have long dominated specialist thinking on modern human origins. The first posits that modern people emerged in a limited area and spread from there to replace archaic people elsewhere. Proponents of this view currently favor Africa as the modern human birthplace.1–5 The second suggests that the evolution of modern humans was not geographically restricted, but invlved substantial continuity between archaic and modern populations in all major regions of the occupied world.6–7 Based solely on the fossil record, both hypotheses are equally defensible, but the spread‐and‐replationships scenario is far more strongly supported by burgeoning data on the genetic relationships and diversity of living humans.8–16 These data impy that there was a common ancestor for all living humans in Africa between 280,000 and 140,000 year ago, and that Neanderthals and other archaic humans who inhabited Eurasia during the same interval contributed few, if any, genes to living peiple. I argue here that the spread‐and‐replacement hypothesis is also more compatible with a third line of evidence: the spread‐and‐replacement hypothesis is also more compatible with a third line of evidence: the archeological record for human behavioral evolution.
Human behavioral ecology: I
Authors: Smith Eric Alden
Published: June 2005

New fields of inquiry rarely spring fully grown from the forehead of a single genius, and in addition, it is often difficult to decide when a related set of inquiries has coalesced sufficiently to define a field. As measured by the solicitation and publication of review articles, human behavioral ecology has recently become a self‐conscious field, for this is the third essay to review it1,2 and a book‐length survey will appear later this year.3 In this two‐part article, I will try to give readers a sense of the field by outlining its theoretical and methodological principles and key issues and by summarizing representative studies and unresolved questions in three main topical areas: subsistence strategies (Part I) and reproductive strategies and social interactions (Part II).
A method to detect excess risk of disease in structured data: Cancer in relatives of retinoblastoma patients
Authors: Chakraborty Ranajit , Weiss Kenneth M. , Majumder Partha P. , Strong Louise C. , Herson Jay , Rao D. C.
Published: June 2005

It is often of interest to know whether there is increased occurrence of a trait in a pedigree or other structured set of epidemiological data. In answering such questions most current methods use aggregate measures, such as relative risk, that may not relate the outcome for each individual to that individual's risk. In this paper we present a simple method, and its computational algorithm, to overcome this limitation. This new method also permits one to identify high‐risk families or subsets of a collection of data, which is not always possible using other approaches.

In a study of cancer risk among relatives of retinoblastoma patients, by applying this new method it was found that 11 of 33 families each obtained through a unilateral retinoblastoma patient are at statistically high risk of cancer at all sites combined, while there are 15 of 47 such families obtained through a bilaterally affected proband. These results are unlikely to have occured by chance, indicating an overall excess risk in the ancestors of these retinoblastoma cases.

The proposed test procedure does not specify the cause of elevated risk; however, a method is proposed that provides some indication regarding possible causal mechanisms under some circumstances.
Nonrandom sampling in human genetics: Skewness and kurtosis
Authors: Chakraborty Ranajit , Hanis Craig L. , Rao D. C.
Published: June 2005

When a multivariate normal sample is chosen from a truncated space of one of its components one can no longer make use of the normality assumption for the sample observations or for the estimates derived from them. In this paper, skewness and kurtosis for each component are derived analytically under a broad class of nonrandom sampling. It is shown that the distortions in skewness and kurtosis produced by nonrandomness are negligible, except those for the component with respect to which the selection of sampling regions is based. The ususal tests of normality from sample values of skewness and kurtosis measures remain valid under nonrandom sampling, except for the selection variable. The implications of these analytical results in the context of commingling analysis in genetic epidemiology are discussed. It is recommended that when samples of families are obtained through nonrandomly ascertained probands, a commingling analysis should treat each relative class separately, since such analyses based on the pooled sample of individuals may involve unspecified bias in the levels of the test procedure.
Estimation of genetic model parameters: Variables correlated with a quantitative phenotype exhibiting major locus inheritance
Authors: Hasstedt Sandra J. , Moll Patricia P. , Rao D. C.
Published: June 2005

A major locus that is detected through its effect on one phenotype (a primary trait) may also affect other quantitative phenotypes or qualitative disease endpoints (secondary traits). The pattern of effects for the mutant allele. The effects are directly estimable when “measured genotypes” or a tightly linked marker allow unambiguous assignment of major locus genotypes. When genotype assignments are ambiguous for a major locus detected through its effect on a quantitative primary trait, we propose estimators using genotypic probabilities. Making certain reasonable assumptions, we demonstrate asymptotic unbiasedness of these genotypic probability estimators of the genotypic means and variances for either the quantitative primary or secondary traits, of the covariances between quantitative primary and secondary traits, and of prevalences for the secondary qualitative traits. An important application of genotypic probability estimators is to define an effect of a major locus that cannot be detected upon analysis of the variable; for example, major locus effects may be defined for hypertension or blood pressure as secondary traits, but not detected as primary traits.
Robust methods for the detection of genetic linkage for quantitative data from pedigrees
Authors: Amos C. I. , Elston R. C. , Rao D. C.
Published: June 2005

The robust method for detecting linkage developed by Haseman and Elston [The investigation of linkage between a quantitative trait and a marker locus. Behav Genet 2:3‐19, 1972] for data from sib pairs is extended to any type of noninbred relative pair. The regression of the squared relative‐pair trait difference on the estimated proportion of genes identical by descent (i.b.d.) at a marker locus is shown to depend upon the recombination fraction between the two loci; the regression coefficient is negative if the trait and marker loci are linked. A test for linkage based on data from any informative type of relative pair can thus be obtained by testing that this regression coefficient is less than zero. Formulae for the asymptotic power of such tests for linkage based upon independent relative pairs are developed. Results are also given for the special case in which the proportion of genes shared i.b.d. for relative pairs is known. Finally, a general algorithm is described that will incorporate all available pedigree data to calculate an estimate of the proportion of genes that a relative pair shares i.b.d. at a marker locus.
A variance components/major locus likelihood approximation on quantitative data
Authors: Hasstedt Sandra J. , Vogler G. P. , Rao D. C.
Published: June 2005

The variance components/major locus model encompasses a major locus, a polygenic component, and shared environmental effects. The model attributes familial correlations to polygenic and shared environmental effects when testing for major locus inheritance or accounts for the major locus when estimating variance components.

Because exact computation of the likelihood of the variance components/major locus model on quantitative data requires excessive computer time, I developed an approximation. The approximation retained the general shape of the likelihood surface. Accuracy of the approximation did not vary consistently with allele frequency or the size of the major locus effect.
Effect of cohort differences in smoking prevalence on models of lung cancer susceptibility
Authors: Sellers Thomas A. , Bailey‐wilson Joan E. , Potter John D. , Rich Stephen S. , Rothschild Henry , Elston Robert C. , Mulvihill John J.
Published: June 2005

Data on 337 lung cancer families were analyzed to determine if known cohort differences in parental cigarette consumption influence parameters from a segregation analysis. Previous results suggested that, after allowing for an individual's pack‐years of tobacco exposure, Mendelian codominant inheritance of an allele that produced an earlier age of onset provided a good fit to the data. In the present study, the data were split into two groups of families: probands age 60 and over (born before WWI) and probands younger than age 60. This partition of the data by age of the proband was done to separate families in which there were parents who were less likely to smoke from those with parents more likely to smoke—predicated on the known increase of smoking prevalence after World War I. For the younger proband families (those with parents more likely to smoke), only Mendelian codominant inheritance adequately fit the data. The hypotheses of no major type, environmental transmission, and Mendelian dominant or recessive inheritance were rejected. In contrast to our earlier findings, the estimate of population susceptibility increased from 28% in the total data to 60% in this subset. In the older proband families (those with parents less likely to smoke), the no major type and environmental hypotheses were rejected; further, none of the Mendelian models could be distinguished. Our results demonstrate that cohort differences, probably in exposure to tobacco, can confound parameters of a segregation analysis, and suggest that the genetic component of lung cancer may be greater than previously estimated. It further suggests that susceptibility to lung cancer occurs as a function of susceptibility to the effects of tobacco smoking. © 1992 Wiley‐Liss, Inc.
Two common polymorphisms in the APO A‐IV coding gene: Their evolution and linkage disequilibrium
Authors: Ilyas kamboh M. , Hamman Richard F. , Ferrell Robert E. , Mulvihill John J.
Published: June 2005

Human apolipoprotein A‐IV (APO A‐IV) exhibits a common protein polymorphism detectable by isoelectric focusing (IEF) due to a single base substitution at codon 360 which replaces the frequently occurring glutamine residue (allele 1) with histidine (allele 2). Recently, sequence analysis of the APO A‐IV coding region has revealed another common nucleotide substitution at codon 347 which converts the commonly present threonine residue (allele A) into serine (allele T). In order to investigate the extent of genetic variation at codon 347, we screened DNA samples from 192 unrelated individuals using a polymerase chain reaction based assay. The frequencies of the two alleles, A‐IV*A and A‐IV*T, were 0.81 and 0.19, respectively, with average heterozygosity 0.31. Genetic screening of the corresponding 192 plasma samples by IEF gave frequencies of 0.922 and 0.078 for the A‐IV*1 and A‐IV*2 alleles, respectively, at codon 360 with average heterozygosity 0.14. Genotype data at the two polymorphic sites were used to assign unequivocal haplotypes to all the 384 chromosomes. Of the expected four haplotypes (A1, T1, A2, and T2) only three were observed and their frequencies were 0.732 for A1, 0.190 for T1 and 0.078 for A2, with average heterozygosity 0.42. Although our data indicate significant linkage disequilibrium between the two sites (χ = 7.65, P>0.006, standardized disequilibrium constant ψ = −0.14) the degree of nonrandom association varied between alleles at the two sites. Based upon allele frequency data and variable linkage disequilibrium between alleles, we propose that the A2 and T1 haplotypes may have evolved from the parental A1 haplotype by two independent mutations. © 1992 Wiley‐Liss, Inc.
Segregation analysis of height‐adjusted weight with generation‐ and age‐dependent effects: The Nancy family study
Authors: Tiret Laurence , André Jean‐Luc , Ducimetière Pierre , Herbeth Bernard , Rakotovao Roger , Guegen René , Spyckerelle Yves , Cambien François
Published: June 2005

A segregation analysis using a regressive model with generation‐ and age‐dependent effects was applied to familial data of height‐adjusted weight to investigate the major gene hypothesis. The sample included 629 nuclear families with 2,534 members volunteering for a free health check‐up in the Preventive Medicine Center of Vandoeuvre‐lès‐Nancy, France. The familial correlations were 0.094 ± 0.040 between spouses, 0.198 ± 0.023 between parent and offspring, and 0.327 ± 0.034 between siblings. The variability of the trait was higher in parents than in offspring. The most parsimonious genetic model indicated a codominant major effect increasing with age in childhood, then stabilizing in adulthood. The same data were analyzed using the classical mixed model, assuming equality of variances between parents and offspring, no resemblance between spouses, similar parent–offspring and sib–sib correlations, and identical effects in parents and offspring. This analysis indicated a recessive solution. In both analyses, mendelian transmission was rejected. However, the mixture of two distributions in the recessive model, instead of three in the codominant one, was less constraining with respect to the test of transmission probabilities, and the rejection of mendelian transmission was due to a single family in the recessive case, instead of several families in the codominant one. This could possibly explain why previous studies, all using the mixed model, found evidence for a recessive major gene. Although the major gene hypothesis cannot be definitely ruled out from our results, the mechanism appears more complex than the effect of one single gene. © 1992 Wiley‐Liss, Inc.
Apo E allele frequencies in younger (age 42–50) vs older (age 65–90) women
Authors: Cauley Jane A. , Eichner June E. , Ilyas Kamboh M. , Ferrell Robert E. , Kuller Lewis H.
Published: June 2005

Allelic variation at the apolipoprotien E (Apo E) structural locus has been shown to influence concentrations of total cholesterol and low density lipoprotein cholesterol (LDL‐C). Apo E has six phenotypes resulting from three common alleles at this locus. The ϵ2 allele is associated with lower LDL‐C and the ϵ4 allele with higher LDL‐C. In the current study, we compared the ϵ allele distribution in two cohorts of white women recruited from population based listing of southwestern Pennsylvania. The “younger” cohort consisted of 473 women, age 42–50; the “older” cohort, 870 women, age 65–90. A comparison of the overall distribution of allele frequencies in the two cohorts was significantly different. The allele frequency of ϵ4 was lower in the older cohort (0.98 vs. 0.122, P = 1.08) and the ϵ2 allele frequency was higher (0.084 vs. 0.059, P = 0.05) in the older cohort. These observations are consistent with the hypothesis that there may be a selection against individuals with the ϵ4 allele. However, future research is needed to confirm this observation and to compare survival in individuals by their ϵ allele. © 1993 Wiley‐Liss. Inc.
Linkage between quantitative trait and marker loci: Methods using all relative pairs
Authors: Olson Jane M. , Wijsman Ellen M.
Published: June 2005

Relative‐pair methods for detection of linkage between a quantitative trait and a marker locus have been proposed by a number of authors [e.g., Haseman and Elston, Behav Genet 3–19, 1972; Amos and Elston, Genet Epidemiol 349–360, 1989]. However, development of tests of significance that combine information from different types of relative pairs has been hampered by the presence of correlations between relative pairs from the same pedigree. In this paper, the methodology of generalized estimating equations is used to provide an estimate of the robust covariance matrix of the estimates of the set of relative‐pair‐type‐specific regression parameters. Using this matrix, an asymptotically most powerful test of linkage which optimally combines the information contained in the different types of relative pairs is constructed. This test requires optimal weights that depend on unknown values of heritability and recombination fraction to be chosen a priori. However, simulations show that, in the regions of recombination fraction and heritability of practical interest, the power of the test does not depend strongly on the assumptions made when chosing the optimal weights; as a result, weights that depend only on the number of each type of relative pair and the variability of the marker identity‐by‐descent probabilities work well in practice. In addition, an approximation to the regression model leads to a simple approach to testing linkage in which only a single regression parameter is estimated from data containing different types of relative pairs. The resulting test is slightly less powerful than the test described above, but its computational simplicity and lack of dependence on a priori weighting schemes suggest potential usefulness in large linkage studies. © 1993 Wiley‐Liss. Inc.