Bioassay of kinship in Micronesia

Phenotype bioassay agrees with clan isonymy, anthropometrics, and migration in estimating the mean kinship within a Micronesian population, relative to large distances, as 0.05. Various calculations of occupancy for the Eastern Carolines from ethnohistory, kinship, and glottochronology average around 1,000 years. Estimates of isolation by distance are in agreement for different indicators of population structure. Problems of kinship bioassay are discussed.     

The evolution of matrilineal kinship organization

Matrilineal kinship organization is a human social system that emphasizes interactions between matrilineal kin, i.e. individuals related only through females. The ‘matrilineal puzzle’ refers to the potential for tension characteristic of this social system, owing to the conflict between the interests and responsibilities of men in their roles as brother/uncle versus husband/father. From an evolutionary perspective, matrilineal kinship organization is puzzling when it diverts investment of resources from the individuals who provide the potentially highest reproductive returns. I use a game-theoretic framework to investigate a particular form of matrilineal inheritance—the transfer of property from a maternal uncle to a sororal nephew. The analysis reveals two mechanisms that may make this strategy a stable evolutionary outcome. First, a polygynous male has multiple wives, and hence multiple brothers-in-law; with matrilineal inheritance, each additional brother-in-law may transfer resources to the male''s wife''s offspring, thus potentially contributing to the male''s inclusive fitness. Second, the husband of a polyandrous female is effectively ‘sharing’ paternity with other men; depending on the number of husbands, he may be better off investing in his sister''s offspring. I conclude by discussing how these results address the challenges posed by the occurrence of matrilineal kinship organization.     

Inbreeding and kinship in the ant Plagiolepis pygmaea

In ants the presence of multiple reproductive queens (polygyny) decreases the relatedness among workers and the brood they rear, and subsequently dilutes their inclusive fitness benefits from helping. However, adoption of colony daughters, low male dispersal in conjunction with intranidal (within nest) mating and colony reproduction by budding may preserve local genetic differences, and slow down the erosion of relatedness. Reduced dispersal and intranidal mating may, however, also lead to detrimental effects owing to competition and inbreeding. We studied mating and dispersal patterns, and colony kinship in three populations of the polygynous ant Plagiolepis pygmaea using microsatellite markers. We found that the populations were genetically differentiated, but also a considerable degree of genetic structuring within populations. The genetic viscosity within populations can be attributed to few genetically homogeneous colony networks, which presumably have arisen through colony reproduction by budding. Hence, selection may act at different levels, the individuals, the colonies and colony networks. All populations were also significantly inbred (F=0.265) suggesting high frequencies of intranidal mating and low male dispersal. Consequently the mean regression relatedness among workers was significantly higher (r = 0.529-0.546) than would be expected under the typically reported number (5-35) of queens in nests of the species. Furthermore, new queens were mainly recruited from their natal or a neighbouring related colony. Finally, the effective number of queens coincided with that found upon excavation, suggesting low reproductive skew.     

Haplotype kinship for three populations of the Goettingen minipig

To overcome limitations of diversity measures applied to livestock breeds marker based estimations of kinship within and between populations were proposed. This concept was extended from the single locus consideration to chromosomal segments of a given length in Morgan. Algorithms for the derivation of haplotype kinship were suggested and the behaviour of marker based haplotype kinship was investigated theoretically. In the present study the results of the first practical application of this concept are presented. Full sib pairs of three sub-populations of the Goettingen minipig were genotyped for six chromosome segments. After haplotype reconstruction the haplotypes were compared and mean haplotype kinships were estimated within and between populations. Based on haplotype kinships a distance measure is proposed which is approximatively linear with the number of generations since fission. The haplotype kinship distances, the respective standard errors and the pedigree-based expected values are presented and are shown to reflect the true population history better than distances based on single-locus kinships. However the marker estimated haplotype kinship reveals variable among segments. This leads to high standard errors of the respective distances. Possible reasons for this phenomenon are discussed and a pedigree-based approach to correct for identical haplotypes which are not identical by descent is proposed.     

Alternative bioassays of kinship between loci.

In this study four asymptotically equivalent estimates of kinship are derived, in the general case and for kinship between multiallelic loci. Two estimates based on chi 2 agree closely, with the Shannon estimate giving the smaller variance. The PAH, GH, GM, and HBB systems conform to a recombinational model with an evolutionary size of approximately 4,000 and a ratio of recombination to physical distance of approximately 1.4 X 10(-5) morgans/kb, as predicted on the basis of the genetic and physical lengths of the human genome. The INS and D11S12 systems have a much more rapid decline of kinship with physical distance, suggesting overlapping RFLPs (unrecognized allelism), recombinational hot spots, or selection. Sources of error in predicting kinship over small distances are discussed.     

Beyond the everyday: sustaining kinship in western Kenya

This article considers the efforts people in western Kenya have been making to uphold an ideology and practice of the natal home and kin group as morally authoritative, in a context where the very survival of many homes and families has been compromised by the devastating effects of AIDS‐related deaths and impoverishment. It traces how orphaned adults, who have little experience or memory of living among natal kin at natal homes, make concerted efforts to reconnect – often in necessarily improvised ways – with what survives of their natal kin and home. For women, in particular, such efforts seem less motivated by immediate material interests and more focused on demonstrating lineal solidarity as a means to affirming their moral personhood and value. The analysis addresses how people lacking shared everyday experiences of kinship and homes sustain the possibility of their kinship futures through a combination of imagination and ideological commitment.     

Sex,kinship, and the evolution of social manipulation

In recent years kin selection has been widely used to explain social systems and the evolution of complex social traits. However, because a knowledge of kin is a prerequisite of kin selection theory, and because a male has less certainty of kin and, in many cases, few or none available to him within a social group, he will be unable to favor kin or benefit from them as reliably as will a female. It is predicted, therefore, that social strategies involving unrelated individuals will be more common among males than females and suggested that the greater encephalization among higher mammals, particularly primates, allowed complex nonkin strategies of social manipulation to evolve, realizing its greatest sophistication in human political systems. Finally, the question whether selection for certain types of social strategies in males may not have led to differences from females in assessment and manipulation skills is considered.     

Effect of kinship on the allopreening among juvenile Bengalese finches

Kin-directed affiliative behavior is widespread in social animals and kin selection theory suggests that such behavior increases fitness of the performer and is thus adaptive. Allopreening in birds is an altruistic behavior as it involves cleaning body parts that cannot be cleaned by self-preening. In this study, we investigated the effects of genetic relatedness on allopreening behavior among juveniles of the Bengalese finch Lonchura striata domestica shortly after the cessation of parental care. Nestlings were cross-fostered in order to distinguish the effects of genetic relatedness (sharing genetic parents) from the effects of familiarity (sharing rearing environment). Preening bouts toward siblings were more frequent and of longer duration than toward non-siblings. The frequency and duration of physical contact within a preening bout did not differ between siblings and non-siblings. In addition, the frequency and duration of preening bouts did not differ between the juveniles that were reared by the same foster parents and between those that were not. Our results suggest that Bengalese finch juveniles recognized siblings and performed affiliative behavior based on genetic similarity rather than familiarity.     

Genetic investigation of the patrilineal kinship structure of early medieval Ireland

A previous study of Irish Y-chromosomes uncovered a likely patrilineal kinship basis to the most prominent early Irish tribal entity/kingdom, the Uí Néill, who dominated the North of the Island during the early medieval period (600-1,000 AD). However, it is unknown to what extent this was a general feature of the multitude of Irish kingdoms that existed over the same period. Irish surnames are patrilineally inherited in a similar manner to the Y-chromosome and their origin can often be traced to pre-existing tribal units. We genotyped 17 microsatellites in 247 Y-chromosomes from men with surnames that are purported to be derived from two different tribes (Eóganacht and Dál Cais) from the Southern province of Munster, as well as a third cohort of random names from the same geographic area. Although there is some sharing of Y-chromosomes between surnames of the same putative origin, there was no clear distinction between either grouping and the control, suggesting that the level of Uí Néill patrilineal kinship was not a universal feature of Irish tribal units. In turn this argues that an extensive extended clan or biological legacy of an eponymous founding ancestor was not necessarily a crucial factor in their establishment.     

Feedback loop between kinship and dominance: the macaque model

There is growing evidence that macaque social systems represent sets of coadapted traits in which strength of hierarchies and degree of nepotism covary. A framework is developed to explain the link between dominance and kinship phenomena, assuming that power brought by alliances among non-kin is allometrically related to those involving relatives. This can account for the type of social relationships observed in "despotic" systems vs. "egalitarian" ones. When social bonds are mostly founded on kinship, lineages are closed and social power generated by coalitions among relatives may reach high levels; social power frequently outweighs the fighting abilities of single individuals, and asymmetry of dominance between group members may be marked. When lineages are more open, social bonds and alliances are less kin-biased, social relationships are more equal, and as the influence of coalitions is less important, the individual retains a certain degree of freedom in relation to the power of kin-networks. Acknowledging that the balance between individual and social power is not set at the same level across different species can explain a number of variations in rules of rank inheritance and relative dominance of males and females among macaques. The framework illustrates how epigenetic processes may shape complex features of primate social systems, and offers opportunities for testing.     

High resolution two-dimensional electrophoresis of basic as well as acidic proteins.

A previously described two-dimensional electrophoresis procedure (O'Farrell, 1975) combined isoelectric focusing and sodium dodecylsulfate slab gel electrophoresis to give high resolution of proteins with isoelectric points in the range of pH 4–7. This paper describes an alternate procedure for the first dimension which, unlike isoelectric focusing, resolves basic as well as acidic proteins. This method, referred to as nonequilibrium pH gradient electrophoresis (NEPHGE), involves a short time of electrophoresis toward the cathode and separates most proteins according to their isoelectric points. Ampholines of different pH ranges are used to optimize separation of proteins with different isoelectric points. The method is applied to the resolution of basic proteins with pH 7–10 Ampholines, and to the resolution of total cellular proteins with pH 3.5–10 Ampholines. Histones and ribosomal proteins can be readily resolved even though most have isoelectric points beyond the maximum pH attained in these gels. The separation obtained by NEPHGE with pH 3.5–10 Ampholines was compared to that obtained when isoelectric focusing was used in the first dimension. The protein spot size and resolution are similar (each method resolving more than 1000 proteins), but there is less resolution of acidic proteins in this NEPHGE gel due to compression of the pattern. On the other hand, NEPHGE gels extend the range of analysis to include the 15–30% of the proteins which are excluded from isoelectric focusing gels. The distribution of cell proteins according to isoelectric point and molecular weight for a procaryote (E. coli) was compared to that of a eucaryote (African green monkey kidney); the eucaryotic cell proteins are, on the average, larger and more basic.