Levels of selection, altruism, and primate behavior.

Altruistic behaviors seem anomalous from a traditional view of Darwinian natural selection, and evolutionary explanations for them have generated much discussion. The debate centers around four major explanations: classic individual-level selection, reciprocity and game theory, kin selection, and trait-group selection. The historical context and defining criteria of each model must be reviewed before its validity can be assessed. Of these proposed mechanisms, group selection historically has been the most controversial. Although the extent to which empirical data support group selection hypotheses is uncertain, there is evidence for group-level selection among avirulent virus strains and foraging ant queens. Researchers studying mammalian behavior, particularly primatologists, have largely dismissed models of group-level selection. Most discussion of altruism among primates has focused on differences in fitness among individuals within a single group, but students of altruistic behaviors exhibited by primates also need to investigate intergroup variation with respect to these behaviors. Various altruistic behaviors are likely to have evolved through different forms of selection, and each example of apparent altruism therefore needs to be evaluated separately.     

Availability of primate species, research, and management in China.

Approximately 30 institutions are currently engaged in primate research and management in China. New studies record 20 species of primates and their distribution throughout China.     

Soils,time, and primate paleoenvironments

Soils are the skin of the earth. From both poles to the equator, wherever rocks or sediment are exposed at the surface, soils are forming through the physical and chemical action of climate and living organisms. The physical attributes (color, texture, thickness) and chemical makeup of soils vary considerably, depending on the composition of the parent material and other variables: temperature, rainfall and soil moisture, vegetation, soil fauna, and the length of time that soil–forming processes have been at work. United States soil scientists¹ have classified modern soils into ten major groups and numerous subgroups, each reflecting the composition and architecture of the soils and, to some extent, the processes that led to their formation. The physical and chemical processes of soil formation have been active throughout geologic time; the organic processes have been active at least since the Ordovician.² Consequently, nearly all sedimentary rocks that were deposited in nonmarine settings and exposed to the elements contain a record of ancient, buried soils or paleosols. A sequence of these rocks, such as most ancient fluvial (stream) deposits, provides a record of soil paleoenvironments through time. Paleosols are also repositories of the fossils of organisms (body fossils) and the traces of those organisms burrowing, food–seeking, and dwelling activities (ichnofossils). Indeed, most fossil primates are found in paleosols. Careful study of ancient soils gives new, valuable insights into the correct temporal reconstruction of the primate fossil record and the nature of primate paleoenvironments.     

U.S. laws, regulations, and policies important to managers of nonhuman primate colonies

The various animal welfare laws, regulations, policies, accreditation standards, and welfare groups have an obvious impact on the activities of managers of nonhuman primate colonies. Federal organizations such as the Department of Health and Human Services, Department of Interior, the Department of Agriculture, the Department of Transportation, and the Justice Department regulate many aspects of animal management. Pertinent guidance is available through scientific organizations such as the American Association for Accreditation of Laboratory Animal Care and the National Academy of Sciences. Finally, the recommendations of responsible animal welfare organizations should also receive careful consideration.     

Dispersal,nepotism, and primate social behavior

High degrees of relatedness within primate social groups are thought to promote the evolution of altruistic behavior via kin selection. Dispersal, for whatever reason, should limit opportunities for nepotistic behaviors. Conversely, emigration is usually attributed to the avoidance of inbreeding depression. Actual dispersal patterns may result from a balance of these forces. Systematic behavioral differences are expected between taxa that differ in such patterns. In fact, comparisons of (a) colobines vs. cercopithecines, (b) bonnet, stumptailed, and Barbary macaques vs. Japanese and rhesus macaques, and (c) red vs. mantled howler monkeys yield a perplexing blend of unexplained differences and unmet theoretical expectations. Kin selection may be less important than generally believed, and/or methodological standardization more so.     

Ontogeny,auditory structures,and primate evolution

The anatomy of the auditory region, particularly the carotid circulatory patterns and ectotympanic-petrosal relationships, has played a prominent role in primate systematics and phylogenetic reconstructions. Ontogenetic stages of petrosal-ectotympanic relationship are presented for certain strepsirhines. It is suggested that the “ectotympanic tube” or “ossified annulus membrane” found in early Tertiary primates is not necessarily an homologous structure to the true ectotympanic tube seen in haplorhines, and thus cannot be considered a shared, derived feature linking known Paleogene primates from Europe or North America to tarsioid and/or anthropoid ancestry. No fossil primate yet discovered makes a convincing ancestor for the earliest known anthropoids from the Oligocene of Africa. This is probably due to the fact that it still lies undiscovered in the Paleogene of Africa.     

Fibril formation by primate, rodent, and Dutch-hemorrhagic analogues of Alzheimer amyloid beta-protein.

Deposition of extraneuronal fibrils that assemble from the 39-43 residue beta/A4 amyloid protein is one of the earliest histopathological features of Alzheimer's disease. We have used negative-stain electron microscopy, Fourier-transform infrared (FT-IR) spectroscopy, and fiber X-ray diffraction to examine the structure and properties of synthetic peptides corresponding to residues 1-40 of the beta/A4 protein of primate [Pm(1-40); human and monkey], rodent [Ro(1-40); with Arg5-->Gly, Tyr10-->Phe, and His13-->Arg], and hereditary cerebral hemorrhage with amyloidosis of the Dutch type (HCHWA-D) [Du(1-40); with Glu22-->Gln]. As controls, we examined a reverse primate sequence [Pm*(40-1)] and an extensively substituted primate peptide [C(1-40); with Glu3-->Arg, Arg5-->Glu, Asp7-->Val, His13-->Lys, Lys16-->His, Val18-->Asp, Phe19-->Ser, Phe20-->Tyr, Ser26-->Pro, Ala30-->Val, Ile31-->Ala, Met35-->norLeu, Gly38-->Ile, Val39-->Ala, and Val40-->Gly]. The assembly of these peptides was studied to understand the relationship between species-dependent amyloid formation and beta/A4 sequence and the effect of a naturally occurring point mutation of fibrillogenesis. The three N-terminal amino acid differences between Pm(1-40) and Ro(1-40) had virtually no effect on the morphology or organization of the fibrils formed by these peptides, indicating that the lack of amyloid deposits in rodent brain is not due directly to specific changes in its beta/A4 sequence. beta-Sheet and fibril formation, judged by FT-IR, was maximal within the pH range 5-8 for Pm(1-40), pH 5-10.5 for Du(1-40), and pH 2.5-8 for Ro(1-40).(ABSTRACT TRUNCATED AT 250 WORDS)     

Teeth, brains, and primate life histories

This paper explores the correlates of variation in dental development across the order Primates. We are particularly interested in how 1) dental precocity (percentage of total postcanine primary and secondary teeth that have erupted at selected absolute ages and life cycle stages) and 2) dental endowment at weaning (percentage of adult postcanine occlusal area that is present at weaning) are related to variation in body or brain size and diet in primates. We ask whether folivores have more accelerated dental schedules than do like-sized frugivores, and if so, to what extent this is part and parcel of a general pattern of acceleration of life histories in more folivorous taxa. What is the adaptive significance of variation in dental eruption schedules across the order Primates? We show that folivorous primate species tend to exhibit more rapid dental development (on an absolute scale) than comparably sized frugivores, and their dental development tends to be more advanced at weaning. Our data affirm an important role for brain (rather than body) size as a predictor of both absolute and relative dental development. Tests of alternative dietary hypotheses offer the strongest support for the foraging independence and food processing hypotheses.     

Characterization of primate bronchoalveolar mast cells. I. IgE-dependent release of histamine, leukotrienes, and prostaglandins

Large numbers of functional mast cells were obtained by bronchoalveolar lavage (BAL) of Macaca arctoides monkeys that had been infected with the nematode Ascaris suum. These lavage cells, of which 21% were mast cells, released histamine, LTC4, and PGD2 in a concentration-dependent fashion when challenged with ascaris antigen or antibody to human IgE. However, there was no release of histamine when these cells were challenged with compound 48/80. The amount of mediator released was highly dependent on the sensitivity of the cells to immunologic challenge, but was generally in the range of 2 to 5 micrograms histamine (30 to 70% of total), 20 to 80 ng LTC4, and 100 to 300 ng PGD2 per 10(6) mast cells when maximally challenged. Other eicosanoids measured were released only in much smaller quantities. Maximal values were 4 ng LTB4, 2 ng PGE2, and approximately 10 to 20 ng PGF2 alpha per 10(6) mast cells. The amount of LTC4 and PGD2 released correlated with the release of histamine, the calculated regression line indicating that 18 ng LTC4 and 50 ng PGD2 were released per microgram of histamine released. This correlation suggests that the majority of the LTC4 and PGD2 released was probably mast cell-derived. Further support for this conclusion was given by the observation that when lavage cells were fractioned on continuous Percoll gradients, the ability to release LTC4 and PGD2 on immunologic challenge coincided with the peak of mast cells.     

Inbreeding,kin selection,and primate social evolution

In this paper I argue (a) that the study of kin selection may be facilitated by looking for influences of inbreeding, which is an important aspect of a population's genetic structure; (b) that in nonhuman primates the level of inbreeding will be largely a function of the rate of migration by individuals, usually only of one sex, between social units or troops; (c) that many primate species live in relatively outbred groups, and that their social structure reflects this; and (d) that extensive social contrasts between bonnet and pigtail macaques reflect evolution by kin selection under different levels of inbreeding.     

Karyotype abnormalities in two primate species, Pygathrix nemaeus and Lemur coronatus.

The karyotypes of 7 douc langurs (Pygathrix nemaeus) and 3 crowned lemurs (Lemur coronatus) were examined. Abnormalities in 23.5% of the karyotypes of 1 male douc langur were associated with a history of fathering stillborns and abortuses (38%). Karyotype analysis of an apparently normal female lemur revealed three differing karyotypes, one normal and two abnormal.     

Genes,development, and evolvability in primate evolution

Development is the process whereby a fertilized cell becomes a mature individual. In metazoans, this complex process involves the differentiation of somatic cells into committed cell and tissue types; the organization and migration of cells, tissues, and anatomical structures relative to one another; and growth. 1 Development matters to evolution in two ways. First, development carries out heritable genetic instructions contained in zygotes to produce functioning yet phenotypically varied individuals. At the population level, this variation in form and function among individuals provides the “raw material” for evolution. Second, the mechanisms of development influence the magnitude, direction, and interdependence of heritable phenotypic variation among traits. Together with phenomena such as genetic drift, organismal development determines the raw material available to selection and thus influences the rate and direction of phenotypic evolution. 2 , 3     

Purification of an ultraviolet-inducible, damage-specific DNA-binding protein from primate cells.

A UV-inducible, damage-specific DNA-binding (DDB) protein with high affinity for double-stranded UV-irradiated DNA has been identified recently in monkey kidney (CV-1) cells (Hirschfeld, S., Levine, A. S., Ozato, K., and Proti?, M. (1990) Mol. Cell. Biol. 10, 2041-2048). We have now purified the DDB protein from extracts of CV-1 cells using hydroxylapatite, phosphocellulose, Mono S, and DNA-affinity column chromatography. The DDB activity, either from mock-treated or UV-induced cells, is heterodisperse in column chromatography, and separation of three forms of the protein was obtained on a phosphocellulose column. Analysis of purified preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that greater than 90% of all three forms is a protein of approximately 126 kDa. The size of the native DDB protein was deduced from gel filtration and native polyacrylamide gel electrophoresis to be approximately 210 kDa, which suggests that the native DDB protein in solution is a homodimer. Preparations of partially purified DDB protein from UV-treated cells have enhanced levels of DDB activity and the protein when compared with similar preparations from mock-treated cells. This damage-recognition protein, alone or in conjunction with other subunits, may be of general importance for the initial recognition of DNA damage in mammals.     

Functional implications of primate enamel thickness.

Recent evolutionary interpretations of Hominoidea have postulated functional relationships between tooth form, diet and masticatory biomechanics. A major consideration is the durability of the tooth under certain dietary conditions. Teeth with low cusps and thicker enamel are able to withstand heavy mastication of abrasive food bolus for a longer period. When comparisons are made between species of higher primates the variables of tooth size, cusp morphology, and enamel thickness appear to be related but until now no systematic analysis has been made to determine the functional relevance of several dental dimensions. This study provides data gained from comparisons of dentition of nine species of primates. Histological sections were made of the post canine teeth and 21 dimensions were compared. The relevant dimensions identified serve to withstand dental wear. The distribution of thicker enamel corresponded to the observed wear planes. Humans had thicker enamel than pongids while the macaque had the thinnest. These preliminary results tend to support theories which explain low, thick, enameled cusps in hominids.