The Descent of Rights and the Descent of Persons

Explication and evaluation of the relative ethnographic and theoretical merits of several constructions of "descent" and "descent groups" (by W. H. R. Rivers, M. Fortes, and W. Goodenough, among others) reveals that relations of descent can have right and duty values only where patri- or matrifiliation is the necessary and sufficient condition for inclusion in a social group. Therefore, only unilineally constituted groups should be described as descent groups.     

Sentimental Structure: Tsimihety Migration and Descent

Patrilineal descent is deployed by the Tsimihety of Madagascar as a criterion for the definition of sentiments of social identity and adhesion, counter-balancing the dispersal brought about by migration. Patrilineality provides Tsimihety with a rationale for the determination of general rights of access to certain resources, in contrast to other criteria such as cognatic kinship, through which specific rights may be claimed.     

The Implications of Marriage Rules and Descent: Categories for Merina Social Structures

Contrary to previous accounts, the Merina have cognatic, endogamous descent categories. As a result of Merina imperialism and French colonialism they are now dispersed all over Madagascar. Those of free descent still prefer to marry endogamously, although embarrassed at the taint of incest attaching to it, and to be buried in the tombs of the original villages around Tananarive which they consider home. The equally numerous population of slave descent has no such ties. They pride themselves on marrying exogamously and establish tombs in the villages where they have settled. The free not only thus maintain attachment to their traditional groupings but derive benefit from them for social and spatial mobility.     

Descent of a split RNA

tmRNA is found in the usual one-piece form in most cyanobacteria, but a small clade has an unusual two-piece form, resulting from processing of a circularly permuted precursor RNA. Here, the secondary structure of the cyanobacterial one-piece tmRNA is established by phylogenetic sequence comparison; it deviates from most tmRNAs in having an extra (fifth) pseudoknot and a branched structure at the end of the tag reading frame. Patterns of sequence conservation between the two cyanobacterial tmRNA types suggest particular events in the evolution of the two-piece form. A simple gene permutation model of tandem duplication followed by loss of the outermost segments appears inadequate. An additional rearrangement is proposed, in which a structure impaired by deletion was regenerated at the expense of a neighboring structure.