Complementary approaches of cytogenetics and molecular biology to the taxonomy and study of speciation processes in lemurs

The lemurs, prosimian primates of Madagascar, constitute a zoological group containing numerous species and subspecies. Their taxonomy remains controversial. Depending on the authors and the techniques they have used, the number of species varies between 39 and 52. In addition, although a monophyletic origin of the settlement of Madagascar is the most commonly held opinion, recent studies based on molecular biology do not exclude two independent colonization events, one involving Daubentonia and a second giving rise to the other lemurs. 1 .     

Asian Primate Classification

In the foreseeable future there is little likelihood of achieving consensus on the number of Asian primate genera and species, and their subspecific composition. There is a more realistic hope of reaching agreement on the number of recognizable subspecies. The latter objective is more urgent because in order to reliably assess generic and specific numbers, it is essential that effective conservation measures are implemented for as many subspecies as possible. This cannot be comprehensively accomplished until their validity is assessed and they are satisfactorily established and defined. The Asian primate classification that we present is the outcome of electronic communication among the co-authors after a workshop, which was especially convened to attempt to determine the number of recognizable primate subspecies and to identify potentially recognizable subspecies. The generic and specific arrangement is a compromise that does not necessarily reflect the individual views of the co-authors: 183 subspecies in 77 species in 16 genera. The 31 subspecies allotted a low credibility rating are almost balanced by the 22 scientifically unnamed populations that may warrant subspecific status.     

Do exaggerated sexual swellings function in female mating competition in primates? A comparative test of the reliable indicator hypothesis

The reliable indicator hypothesis proposes that exaggeratedsexual swellings in female primates serve as honest signalsof female quality that function in female—female competitionover mates. We examined a version of this hypothesis usinginterspecific data to test whether exaggerated sexual swellingsare associated with female mating competition, as measured usingthe adult sex ratio, female canine size, and expected femalemating synchrony. The ratio of females to males and relativecanine size declined over evolutionary transitions in swellingstate, thus providing no support for the reliable indicatorhypothesis. Expected female mating synchrony increased over evolutionary transitions in swelling state, but this patterndid not approach significance, and the patterns were oppositeto predictions when controlling for the number of males inthe group. In addition to these comparative tests, we reviewedevidence concerning individual attributes of females relativeto characteristics of their swellings. Contrary to the reliableindicator hypothesis, the least fertile females, or those leastlikely to raise surviving offspring, often have larger swellings.We consider the statistical power of our tests, discuss thetheoretical and empirical bases for our comparative predictions,and consider other lines of evidence needed to test the reliableindicator hypothesis. We also discuss an alternative hypothesis, the graded signal hypothesis, which combines the benefits ofbiasing and confusing paternity through a novel mechanism andis testable in the field and the laboratory.     

Model life tables for the larger old world monkeys

Mortality statistics for 25 populations of the larger Old World monkeys (members of the subfamily Cercopithecinae) were evaluated with a competing hazard model of mortality. The best eight of these life tables were combined to generate a standard model life table representative of the mortality patterns of these primates. Two applications of the standard model to smooth, graduate, and compare life tables based on limited and defective data are presented.     

Étude électrophorétique de l'hybride expérimental entre Papio anubis et P. cynocephalus

Hybrids between Papio anubis and P. cynocephalus occur in nature. We have studied laboratory bred hybrids, together with their backcrossed offspring. Electrophoretic experiments on the proteins, serum enzymes and erythrocytes obtained from both hybrids and parents lead to three conclusions. First, both parents and hybrids possess proteins having identical mobilities; this case is the most frequent in the 23 loci studied. Second, individual polymorphism caused by, for example, carbonic anhydrase I or transferrin in one or both parents results in the appearance of a codominant phenotype in the hybrid, when the parental components are distinguishable. Third, when other enzymes such as albumin, alkaline phosphatase, haemoglobin and the serum esterases have particular electrophoretic mobilities in the parents, then the hybrid is again codominant; a particularly interesting case among the esterases is that of pseudocholinesterase, where the paternal component is partially repressed in the hybrid. The hybrid than exhibits the phenomenon of allelic repression of at least one gene, which confirms the taxonomic position of species of the two forms of Papio studied.     

Serum concentrations of 1,25-dihydroxyvitamin D3 in Platyrrhini and Catarrhini: A phylogenetic appraisal

We measured the serum concentration of 25-hydroxyvitamin D₃ (25-OH-D₃) and 1,25-dihydroxyvitamin D₃ (1,25-[OH]₂-D₃) in 23 different Platyrrhines from four different genera and in 21 Catarrhines from six different genera in residence at the Los Angeles Zoo. The mean (±S.E.) serum concentration of 1,25-(OH)₂-D₃ was significantly greater in Platyrrhines (810 ± 119 pg/ml) than in Catarrhines (61 ± 5 pg/ml), suggesting that high circulating concentrations of the active vitamin D hormone were a characteristic of New World primates in both the Cebidae and Callitrichidae family. This increase in the serum concentration of 1,25-(OH)₂-D₃ is probably an adaptational response on the part of Platyrrhini to offset a relative decrease in the concentration of specific receptor for 1,25-(OH)₂-D₃ in target tissues for the hormone.     

The evolution of molar occlusion in the Cercopithecidae and early catarrhines

Those Eocene prosimians which are possible catarrhine ancestors have four blade-like crests on each lower molar. Each crest shears in sequence across two upper molar crests. Occluding crests are concavely curved to hold the foods being sheared. Each of two medial lower molar crests bordering the principal crushing surface shear past single upper molar crests at about the same time the lateral lower molar crests contact the second rank of upper molar crests. Grinding and crushing areas are restricted to hypoconid, trigonid, and protocone surfaces. Oligocene catarrhine molars have increased crushing-grinding capacities and maintained but modify their shearing. As the crushing surface of the protocone expands and a crushing hypocone is added, the “second rank” upper molar shearing crests are functionally reduced. At the same time medial crests are increasingly emphasized so that the total shearing capacity remains virtually unchanged. Marginal shearing blades are straight edged; leading edges of occluding blades are set at different angles to the occlusal plane so that blades contact at only one point at any given time. Early Primates have separate crushing basins surrounded by shearing blades. Catarrhines tend to link expanding crushing surfaces anteroposteriorly into a continuous surface between all molars. A cladistic analysis based on both new and previously recognized characters indicates that: 1, Apidium may be more closely related to Aegyptopithecus than to Parapithecus; 2, cercopithecids are derived from a Parapithecus-related stock; 3, Oreopithecus could equally well have come from an Apidium or Aegyptopithecus stock.