Laterality in Maternal Cradling and Infant Positional Biases: Implications for the Development and Evolution of Hand Preferences in Nonhuman Primates

Left-sided maternal cradling has been widely reported in human populations. In this paper, I review the evidence of laterality in maternal cradling and infant positional biases in non-human primates. The review revealed some evidence of population-left sided cradling in great apes but little consistency in bias was found among Old and New World monkeys. Very little data have been reported in prosimians. I further describe how asymmetries in either maternal cradling or infant positional biases may explain individual and species differences in hand preference.     

Experimental Hybridization Reveals Biased Inheritance of the Internal Transcribed Spacer of the Nuclear Ribosomal DNA in Begonia ×taipeiensis

Begonia × taipeiensis C.-I Peng, a naturally occurring hybrid resulting from B. formosana × B. aptera, in Taiwan. To understand the inheritance of ribosomal DNA in unidirectional hybridization, experiments were conducted using B. formosana and B. aptera as ovule and pollen donors, respectively. The internal transcribed spacer region (ITS) of nuclear ribosomal DNA was amplified from the artificial hybrids, parental species, and natural hybrids. In contrast to the single type of ITS in the parental species, multiple sequences were cloned from both natural and artificial hybrids. A split decomposition network based on ITS nucleotide variation revealed that all but one (clone B14) of the hybrid sequences were “phylogenetically” closely related to B. formosana. Apparently, in such unidirectional hybridization, maternal DNA provided most of phylogenetic information. In the hybrid sequences, in addition to additive polymorphisms inherited from maternal (38.1%) and paternal (30.1%) plants, a novel nucleotide composition (31.8%) was also detected. The “new” characters are seen as noise in phylogenetic inference. They were probably obtained via intramolecular recombination, as gene conversion was not detected. The occurrence of genetic recombination appeared to be nonrandom, with a higher frequency in the ITS1 (3.14%) and ITS2 (3.42%) regions than in the 5.8S RNA gene (2.22%). Given the lack of sexual recombination in B. × taipeiensis and short time span, unequal crossing-over likely contributed to the heterogeneity of the ITS composition in the nuclear genome. Although the sterile hybrids have not attained their own lineage independent from the parental species, a high level of genetic diversity is transmitted asexually and maintained in these plants. Received 7 February 2001/ Accepted in revised form 31 May 2001     

Hormonal Correlates of Maternal Style in Captive Macaques (Macaca fuscata and M. mulatta)

Previous studies on nonhuman primate maternal styles showed that variation in infant-directed behavior falls along two dimensions, traditionally labeled as protectiveness and rejection. We investigated maternal styles in rhesus (Macaca mulatta) and Japanese (M. fuscata) macaques living in analogous captive social groups, and correlated them with the levels of estrogen metabolites excreted in female feces during the perinatal period. We focally observed mother-infant pairs 3 hours per week during the first 12 weeks of infant life. We collected fecal samples twice a week from each mother, starting 4 weeks before delivery and ending 4 weeks after delivery. Three significant components were extracted by principal component analysis from 15 different infant directed behaviors, each reflecting a different aspect of mothering style: rejection is correlated with behavioral measures of maternal opposition to contact; protectiveness is correlated with maternal solicitude; and independence is correlated with time in contact, grooming and cradling. Levels of estrogen metabolites are significantly correlated to rejection but not to protectiveness or independence, indicating that, in nonhuman primates, individual endocrine changes related to maternal behavior might specifically affect the timing of contact interruption.     

Mindreading, Mindshaping, and Evolution

I present and apply some powerful tools for studying humanevolution and the impact of cultural resourceson it. The tools in question are a theory ofniche construction and a theory about theevolutionary significance of extragenetic (and,in particular, of psychological and social)inheritance. These tools are used to show howculturally transmitted resources can berecruited by development and becomegeneratively entrenched. The case study isconstituted by those culturally transmitteditems that social psychologists call`expectancies'. Expectancy effects aremindshaping effects of our mindreadingdispositions. I show how expectancies may havebeen recruited by important human developmentalprocesses (like those involved in languageacquisition and those responsible for genderdifferences) and how they may have becomeentrenched. If the hypothesis is correct, therelation between mindreading and humanevolution is more intricate than usuallythought.     

Nutritional status of the Indian population

High prevalence of low birth weight, high morbidity and mortality in children and poor maternal nutrition of the mother continue to be major nutritional concerns in India. Although nationwide intervention programmes are in operation over two decades, the situation has not changed greatly. In addition, the Indian population is passing through a nutritional transition and is expected to witness higher prevalences of adult non-communicable diseases such as diabetes, hypertension and coronary heart disease according to the theory of ‘fetal origin of adult disease’. Clearly, there is a need for examining several issues of nutritional significance for effective planning of interventions. In particular, maternal nutrition and fetal growth relationship, long term effects of early life undernutrition, interactions of prenatal nutritional experiences and postnatal undernutrition are some of the major issues that have been discussed in the present paper with the help of prospective data from various community nutrition studies carried out in the department.     

植物数量性状遗传体系检测中回交或自交家系重复试验数据的分析方法

为提高主基因 多基因混合遗传分析的精度 ,降低试验误差 ,采用重复内分组随机区组设计 ,对低遗传力性状的B1∶2 和B2∶2 或F2∶3 家系平均数资料进行遗传分析。通过AIC准则和适合性检验比较无主基因 (A - 0 )、1对主基因 (A)、2对主基因 (B)、多基因 (C)、1对主基因 多基因 (D)和 2对主基因 多基因 (E)模型以鉴定其遗传模式。采用IECM算法估计混合模型参数。通过油菜HSTC14×宁油 7号初花期F2∶3 家系平均数资料阐明该方法。     

RFLP marker analysis supports tetrasonic inheritance in Lotus corniculatus L.

Lotus corniculatus is a tetraploid (2n=4x=24) perennial forage legume and has been reported to have tetrasomic inheritance for several traits, although it has also been reported to show disomic inheritance. Molecular markers were used to clarify whether tetrasomic inheritance, disomic inheritance, or a combination of both, was found within an F₂ population arising from a cross between two diverse L. corniculatus accessions. The inheritance of ”tetra-allelic” RFLP markers (markers with four segregating bands) indicated that disomic inheritance could not account for the phenotypic F₂ classes observed, and that only tetrasomic inheritance would explain the observed results. Goodness of fit tests for ”tetra-allelic” and ”tri-allelic” (three segregating bands) RFLP marker data suggested support for chromosomal-type tetrasomic inheritance. RFLP genotypes interpreted from autoradiographic signal intensity provided additional support for tetrasomic inheritance and the occurrence of preferential pairing between parental chromosomes. Bivalent pairing was predominant in the two parental lines and their F₁ hybrid in cytological analyses. L. corniculatus has been classified as both an autotetraploid and an allotetraploid species. RFLP evidence of tetrasomic inheritance gives support for L. corniculatus being classified as an autotetraploid species. Even though bivalent pairing occurs, as seen in other autotetraploid species, pairing between any of the four homologous chromosomes is possible. Preferential pairing in the F₁ hybrid suggests that genome differentiation appears to be minimal between homologs within an accession, while genome differentiation is greater between homologs from different accessions of this genetically diverse species. Received: 16 November 1999 / Accepted: 14 July 2000     

Evidence for differential maternal allocation to eggs in relation to manipulated male attractiveness in the pied flycatcher (Ficedula hypoleuca)

We present evidence of differential maternal allocation to eggs in response to manipulated male attractiveness in the migratory pied flycatcher (Ficedula hypoleuca). We manipulated the size of a male secondary sexual trait, the white forehead patch, right after male arrival to the breeding area and before female arrival. Patch size was (1) enlarged to the maximum observed in the population, (2) reduced by 40% or (3) kept constant by painting with indelible felt markers over the natural feather patch. Male behaviour was affected by the experimental manipulation, as individuals with enlarged patches performed more approaches to the nestbox in response to song playback during the territory occupation and nest-site presentation phases. Females paired with males with reduced forehead patches laid significantly smaller eggs than those paired with males in the control and enlarged-patch treatments. Laying date and clutch size did not differ among the experimental groups. We discuss that manipulations of ornaments designed to study differential allocation at laying should reduce as well as enlarge their expression.