Marriage trends in the Italo-Greeks of Italy

The Italo-Greek ethnolinguistic minority, living in thirteen villages of southern Italy, marry largely amongst themselves but there are some intermarriages with native Italians. The majority of marriages are within the villages, but there is some marriage movement from one Italo-Greek village to another. Data on marriage and birthplace of parents and grandparents obtained by questionnaires to families of primary school children (aged 6-13 years) are analysed, to show the trends in breakdown of isolation over the last two generations.     

Recent increase of the exogamy rate in the Greek ethno-minority of Italy

In a study of the Greek ethno-linguistic community of Italy (nine villages in Apulia and four in Calabria) marriage data was obtained through direct interviews of 1653 families of primary school students (6–13 years old). The information collected consisted of the birth place of parents and grandparents of each informant. The data demonstrated that in the last generation an increase of intermarriage with native Italian speaking individuals occurred both in Apulia and Calabria (Apulia: grandparents 15.7%vs parents 33.5%; Calabria: grandparents 15.2%vs parents 31.9%).     

Excess of malignancies in grandparents of children with malformations? Short communication

In a prospective study, the occurrence of malignancies in children referred to genetic counseling for congenital malformations, in their sibs, parents and grandparents was registered in 120 families by means of personal interviews. One hundred-and-twenty age matched subjects, admitted for acute respiratory infections or trauma, served as controls. No difference in the occurrence of tumors or leukemias between the two groups was found when the values of patients, sibs, and parents were compared. At the same time, the grandparents of probands with malformations had had significantly more malignancies than the grandparents of the controls. This may be explained by the fact that grandparents lived beyond the age of the usual onset of common cancers and leukemias.     

Grandparental Effects on Fertility Vary by Lineage in the United Kingdom

Grandparental presence is known to correlate with the number of grandchildren born, and this effect may vary according to grandparental sex and lineage. However, existing studies of grandparental effects on fertility mostly concern traditional subsistence societies, while evidence from contemporary developed societies is both scarce and mixed. Here, we explore how grandparents affect the transition to second and subsequent children in the contemporary United Kingdom. The longitudinal Millennium Cohort Study (n = 10,295 families) was used to study the association between grandparental investment and parents’ probability of having a new child within 4.5 years. Results show that contact with paternal grandparents is associated with higher probability of parents having a second child. In contrast, contact with maternal grandparents is associated with lower probability of having a third or subsequent child. Kin may have opposite effects on fertility even in contemporary societies, which may explain the lack of consistent effects of grandparental investment on fertility in previous studies.     

Body height in relation to rural-urban migration in Poland

A survey was conducted among 2800 students studying in Wroc?aw, Poland. The questionnaire included questions on the body height of the students and their parents, and place of residence and migration patterns of the students themselves, their parents and their grandparents. Body height in both students and their parents was positively correlated with the size of their place of residence. This was particularly true for male students and their fathers. Body height in students and parents from mobile families was not significantly different from that of their peers from non-mobile families. Body height in mobile individuals was generally between that of non-mobile individuals from rural areas and that of non-mobile individuals from large urban centres. Students from families that had migrated from smaller urban centres to larger ones were taller than students from families that had migrated from rural areas to urban centres. Body height in students was also correlated with the kind of migration that took place. In the students' mothers, body height was higher if the maternal grandparents moved from smaller urban centres to larger urban centres than if the maternal grandparents moved from rural areas to urban centres. In female students, body height depended on whether their mothers had migrated from smaller places of residence to larger places of residence, but was not affected by the degree of migration. Intra-generational migration during the generation of the students' grandparents was associated with increased body height in the students' mothers. On the other hand, intergenerational migration during the generations of the students' grandparents and parents was associated with increased body height in the students' fathers and in female students. Body height was not a reliable indicator of whether an individual migrated from rural areas to Wroc?aw. Far more reliable indicators were the size of the place the student lived their whole life and whether the family had lived in an urban environment for at least two generations.     

Studying parents and grandparents to assess genetic contributions to early-onset disease

Suppose DNA is available from affected individuals, their parents, and their grandparents. Particularly for early-onset diseases, maternally mediated genetic effects can play a role, because the mother determines the prenatal environment. The proposed maximum-likelihood approach for the detection of apparent transmission distortion treats the triad consisting of the affected individual and his or her two parents as the outcome, conditioning on grandparental mating types. Under a null model in which the allele under study does not confer susceptibility, either through linkage or directly, and when there are no maternally mediated genetic effects, conditional probabilities for specific triads are easily derived. A log-linear model permits a likelihood-ratio test (LRT) and allows the estimation of relative penetrances. The proposed approach is robust against genetic population stratification. Missing-data methods permit the inclusion of incomplete families, even if the missing person is the affected grandchild, as is the case when an induced abortion has followed the detection of a malformation. When screening multiple markers, one can begin by genotyping only the grandparents and the affected grandchildren. LRTs based on conditioning on grandparental mating types (i.e., ignoring the parents) have asymptotic relative efficiencies that are typically >150% (per family), compared with tests based on parents. A test for asymmetry in the number of copies carried by maternal versus paternal grandparents yields an LRT specific to maternal effects. One can then genotype the parents for only the genes that passed the initial screen. Conditioning on both the grandparents' and the affected grandchild's genotypes, a third log-linear model captures the remaining information, in an independent LRT for maternal effects.     

Adaptive transgenerational plasticity in an annual plant: grandparental and parental drought stress enhance performance of seedlings in dry soil

Stressful parental (usually maternal) environments can dramatically influence expression of traits in offspring, in some cases resulting in phenotypes that are adaptive to the inducing stress. The ecological and evolutionary impact of such transgenerational plasticity depends on both its persistence across generations and its adaptive value. Few studies have examined both aspects of transgenerational plasticity within a given system. Here we report the results of a growth-chamber study of adaptive transgenerational plasticity across two generations, using the widespread annual plant Polygonum persicaria as a naturally evolved model system. We grew five inbred Polygonum genetic lines in controlled dry vs. moist soil environments for two generations in a fully factorial design, producing replicate individuals of each genetic line with all permutations of grandparental and parental environment. We then measured the effects of these two-generational stress histories on traits critical for functioning in dry soil, in a third (grandchild) generation of seedling offspring raised in the dry treatment. Both grandparental and parental moisture environment significantly influenced seedling development: seedlings of drought-stressed grandparents or parents produced longer root systems that extended deeper and faster into dry soil compared with seedlings of the same genetic lines whose grandparents and/or parents had been amply watered. Offspring of stressed individuals also grew to a greater biomass than offspring of nonstressed parents and grandparents. Importantly, the effects of drought were cumulative over the course of two generations: when both grandparents and parents were drought-stressed, offspring had the greatest provisioning, germinated earliest, and developed into the largest seedlings with the most extensive root systems. Along with these functionally appropriate developmental effects, seedlings produced after two previous drought-stressed generations had significantly greater survivorship in very dry soil than did seedlings with no history of drought. These findings show that plastic responses to naturalistic resource stresses experienced by grandparents and parents can "preadapt" offspring for functioning under the same stresses in ways that measurably influence realized fitness. Possible implications of these environmentally-induced, inherited adaptations are discussed with respect to ecological distribution, persistence under novel stresses, and evolution in natural populations.     

Consequences of a screening programme on the prevalence of congenital hereditary sensorineural deafness in the Australian Cattle Dog

Genetic disease testing programmes are used in domestic animal breeds to guide selective breeding with the aim of reducing disease prevalence. We assessed the change in the prevalence of canine congenital hereditary sensorineural deafness (CHSD) in litters of Australian Cattle Dogs following the introduction of a brainstem auditory evoked response (BAER) testing programme. We studied 608 pups from 122 litters from 10 breeding kennels. Despite 10 years of testing (1998–2008), no substantial reduction in prevalence of CHSD was evident in these 10 breeding kennels. Even for the subset of litters in which both parents were BAER tested as normal hearing (305 pups from 58 litters), there was no evidence of substantial reduction in prevalence. Odds ratios for CHSD in pups for each extra year since testing in the kennel commenced were 1.01 (95% CI, 0.88–1.17) and 1.03 (95% CI, 0.82–1.30) respectively for these populations. Amongst 284 dogs from 54 litters with extended pedigrees and both parents BAER‐tested normal hearing, observed prevalences of CHSD were highest in pups with no BAER‐tested normal grandparents (17% or 5/29) and lowest in pups with all four grandparents tested normal (0% or 0/9). In pups for which one, two and three grandparents tested negative, prevalences of CHSD were 12% (9/74), 9% (9/101) and 8% (6/71) respectively. Hence, testing programmes based on phenotypic screening may not lead to a substantial reduction in recessive genetic disease prevalence over the medium term, even when only tested normal parents are used. Exclusive breeding of litters in which both parents and all four grandparents are BAER‐tested normal is expected to reduce CHSD prevalence in pups to the greatest extent over the long term.     

Kin Relationships and the Caregiving Biases of Grandparents, Aunts, and Uncles

Paternity certainty and matrilineal family ties have been used to explain the asymmetric caregiving of grandparents and aunts and uncles. The proximate mechanisms underlying biased kin investment, however, remain unclear. A central question of the study presented here was whether the parent-kin relationship is an important link in the caregiving. In a two-generational questionnaire study, we asked subjects to estimate the intensity of their relationships to parents, grandparents, aunts, and uncles (emotional closeness, investment received in childhood). In addition, the subjects’ parents rated their emotional closeness to their parents and siblings. We found that the parent-kin relationship was closely linked to the relatives’ child care and could partly explain asymmetric caregiving. Maternal aunts played a special role as caregivers. Especially the mother’s younger or last-born sister cared intensively for nieces and nephews, regardless of her closeness to the subjects’ mother.     

The three pillars of the new family.

Children are the chief sufferers from the growing fragility of marriages and partnerships. They may also suffer from their mothers going out to paid work unless satisfactory alternative arrangements are made for their care, for instance, by bringing in grandparents to look after their grandchildren when the mothers are not at home. Grandparents may also have an important role when parents separate. There is a dearth of facts about what actually happens. The part played by grandparents has been touched on, but nothing more, in the course of studies in baby care and baby-sitting and the repercussions of the illness of the mother. A Grandparent Commission is proposed to set in motion some of the necessary research and to review official policy as it affects grandparents. If grandparents already do a lot for children, and could do more, a measure of optimism about the future of the family could succeed the prevailing pessimism.     

Ancestral feeding and survival of offspring in European corn borer

Experiments were conducted to evaluate the influence of ancestral adult feeding by European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), on larval survival in the field and neonate movement behavior in laboratory. Larval survival was higher when either the grandparental or parental generation had fed, but the feeding sites of the surviving larvae were not affected by ancestral feeding condition. This is the first evidence that grandparental feeding could influence larval survival in the field. Larval movement was observed in the laboratory. Silking speed of neonates was faster when either grandparents or parents had fed, while walking speed was faster only when parents had fed. No broad-sense genetic correlation was found between silking speed and walking speed. Broad-sense heritability among feeding histories were not significant for silking speed, but was significantly greater than zero for walking speed when grandparents fed and parents did not. These intergenerational effects could induce complex population dynamics in this species.     

How Grandparents Matter

Low birth rates in developed societies reflect women’s difficulties in combining work and motherhood. While demographic research has focused on the role of formal childcare in easing this dilemma, evolutionary theory points to the importance of kin. The cooperative breeding hypothesis states that the wider kin group has facilitated women’s reproduction during our evolutionary history. This mechanism has been demonstrated in pre-industrial societies, but there is no direct evidence of beneficial effects of kin’s support on parents’ reproduction in modern societies. Using three-generation longitudinal data anchored in a sample of grandparents aged 55 and over in 1992 in the Netherlands, we show that childcare support from grandparents increases the probability that parents have additional children in the next 8 to 10 years. Grandparental childcare provided to a nephew or niece of childless children did not significantly increase the probability that those children started a family. These results suggest that childcare support by grandparents can enhance their children’s reproductive success in modern societies and is an important factor in people’s fertility decisions, along with the availability of formal childcare.     

水族的体质特征研究

对贵州三都县水族男性２２岁和女性２０岁至６０岁且三代均为水族的４０７人（男２０３、女２０４）进行了活体调查。测量５２项,观察１７项。经计算总结出水族的体质特征。用Ｒｍ值和欧氏距离系数（ｄ）与国内一些民族相比较,水族与贵州仡佬族、广西仡佬族、侗族、苗族、瑶族、彝族、壮族和湖南土家族等较接近,与新疆哈萨克族等较远。     

Information content of the Centre d'Etude du Polymorphisme Humain (CEPH) family structures for linkage studies

Summary This paper derives theoretical values for joint polymorphism information content for two markers from a family structure consisting of four grandparents, two parents, and many offspring. These data determine the efficiency of linkage map construction.     

An RFLP linkage map for loblolly pine based on a three-generation outbred pedigree

A genetic linkage map for loblolly pine (Pinus taeda L.) was constructed using segregation data from a three-generation outbred pedigree consisting of four grandparents, two parents, and 95 F₂ progeny. The map was based predominantly on restriction fragment length polymorphism (RFLP) loci detected by cDNA probes. Sixty-five cDNA and three genomic DNA probes revealed 90 RFLP loci. Six polymorphic isozyme loci were also scored. One-fourth (24%) of the cDNA probes detected more than 1 segregating locus, an indication that multigene families are common in pines. As many as six alleles were observed at a single segregating locus among grandparents and it was not unusual for the progeny to segregate for three or four alleles per locus. Multipoint linkage analysis placed 73 RFLP and 2 isozyme loci into 20 linkage groups; the remaining 17 RFLP and 4 isozyme loci were unlinked. The mapped RFLP probes provide a new set of codominant markers for genetic analyses in loblolly pine.     

Clastogenic effect of the psychotropic drug thioridazine on human chromosomes in vivo

Summary This paper deals with some other population genetic aspects associated with the incidence of a type of primary congenital glaucoma that occurs very frequently in the Gypsy population of Slovakia. In addition to the decreased fertility of affected individuals of Gypsy origin being determined, the relative reproduction fitness and the selection coefficient against this disease were estimated. An increased number of kinship intermarriages in parents of the patients were recorded, namely in the Gypsy group (45.6%). The average inbreeding coefficient for the Gypsy group (F=0.0091) and the non-Gypsy group (F=0.0030) was calculated. Based on the high frequency of primary congenital glaucoma in a relatively small Gypsy subpopulation and on data about their origin, immigration, and settlements in the territory of Slovakia, the authors consider a special case of gene drift—the founder effect—to be the most plausible explanation of the given fact.     

Genetic and environmental contributions to the variance of body height in a sample of first and second degree relatives.

Height was measured in a health screening of the population in Nord-Trøndelag, Norway. Correlations were computed for 24,281 pairs of spouses, 43,613 pairs of parents and offspring, 19,168 pairs of siblings, 1,318 pairs of grandparents and grandchildren, 1,218 cognate avuncular pairs, 849 noncognate avuncular pairs, 175 pairs of same-sexed twins, and smaller groups of other types of relatives. Fitting of structural equation models showed proportions of additive genetic variance of approximately 0.8 for both sexes and small sex-specific effects that probably reflect genetic dominance or environmental sibling effects. The correlations between parents and offspring were significantly lower in old than young cohorts, seeming to imply some kind of interaction effect between genes and environment. © 1992 Wiley-Liss, Inc.     

The intergenerational transmission of Australian Indigenous languages: why language maintenance programmes should be family-focused

By 2050, the majority of Australia’s surviving Indigenous languages are likely to become extinct. The intergenerational transmission of languages in which children acquire languages from their parents and grandparents is a key mechanism for reversing language shift, but many Australian children whose parents speak an Indigenous language do not speak that language. Using a unique, national survey of Australian Indigenous children, I identify factors associated with the successful intergenerational transmission of Indigenous languages within Aboriginal and Torres Strait Islander families. Results highlight the importance of parents’ language use. Although community-level characteristics account for some of the variance in successful language transmission, parents who use Indigenous languages at home, speak them as well as they speak English, and do not also speak a creole language are more likely to pass those languages onto their children.     

Frequency of consanguineous marriages among parents and grandparents of Down patients

Summary The existence of a rare autosomal gene which in the homozygous state would cause mitotic nondisjunction in the Down zygote has been hypothesized in the past by Alfi et al. (1980). This hypothesis can be supported or contradicted by the study of the frequency of consanguineous marriages among parents of affected children. Our study on 242 children affected with Down syndrome does not show any increase in the frequency of consanguineous marriages among their parents with respect to the general population, and therefore does not support the hypothesis of an autosomal gene controlling mitotic nondisjunction. Our data do not show any increase in the frequency of consanguineaous marriages even among paternal and maternal grandparents of the affected children, thus not supporting the other possible explanation of an autosomal recessive condition in one of the patient's parents which would cause meiotic nondisjunction.     

Effects of childhood cancer on long-term survivors and their families.

Problems experienced by families of long-term survivors of acute lymphatic leukaemia and Wilms''s tumour were investigated to find out the best way of using limited resources to improve management of such patients. All patients had received treatment at Alder Hey Children''s Hospital, and all had completed treatment at least two years before the study. A social worker interviewed the parents of each child. The results showed that various aspects of management needed improvement, including: information given to parents at diagnosis of their child''s illness and during subsequent treatment; continuity of care and multidisciplinary teamwork among those caring for the child; greater understanding by school teachers that such children have the same educational needs as others; wider communication by hospital staff with the child''s other relatives, particularly grandparents; financial help for parents; and marital counselling. To help implement these proposals full-time social workers were attached to the hospital. Preliminary results were encouraging, though it is too early to evaluate the long-term effects of the changes.