Search

Sequencing and comparative analyses of genomes from multiple vertebrates are providing insights about the genetic basis for biological diversity. To date, these efforts largely have focused on eutherian mammals, chicken, and fish. In this article, we describe the generation and study of genomic sequences from noneutherian mammals, a group of species occupying unusual phylogenetic positions. A large sequence data set (totaling > 5 Mb) was generated for the same orthologous region in three marsupial (North American opossum, South American opossum, and Australian tammar wallaby) and one monotreme (platypus) genomes. These ancient mammalian genomes are characterized by unusual architectural features with respect to G + C and repeat content, as well as compression relative to human. Approximately 14% and 34% of the human sequence forms alignments with the orthologous sequence from platypus and the marsupials, respectively; these numbers are distinctly lower than that observed with nonprimate eutherian mammals (45-70%). The alignable sequences between human and each marsupial species are not completely overlapping (only 80% common to all three species) nor are the platypus-alignable sequences completely contained within the marsupial-alignable sequences. Phylogenetic analysis of synonymous coding positions reveals that platypus has a notably long branch length, with the human-platypus substitution rate being on average 55% greater than that seen with human-marsupial pairs. Finally, analyses of the major mammalian lineages reveal distinct patterns with respect to the common presence of evolutionarily conserved vertebrate sequences. Our results confirm that genomic sequence from noneutherian mammals can contribute uniquely to unraveling the functional and evolutionary histories of the mammalian genome. comparative genomics | genome sequencing | genome analysis | phylogenetics | mammalian evolution

The origin of primates has had a long history of discussion and debate, with few ever considering the impact of the original body weight on subsequent primate adaptive radiations. Here, I attempt to reconstruct early primate evolution by considering the initial size of primates as well as the critical functional-adaptive events that had to occur prior to the early Eocene. Microcebus is often viewed as a living model, and thus 40-65 g might represent a practical ancestral weight for the origin of primates. I consider a smaller original body weight, likely 10-15 g in actual size, and I address the biological implications for shrew-sized primates by comparing the behavioral ecology of mouse lemurs, our smallest living primates, to another tiny-sized mammalian group, the shrews (Family Soricidae). Several behavioral and ecological characteristics are shared by shrews and mouse lemurs, and several mammalian trends are evident with decreased size. I suggest that a shrew-sized ancestral primate would have had high metabolic, reproductive, and predation rates, relatively low population densities, and a dispersed and solitary existence with a promiscuous mating system. Although small mammals like shrews provide insights concerning the ancestral size of primates, primate origins have always been tied to arboreality. I assess other potential arboreal models such as Ptilocercus and Caluromys. By combining all of this information, I try to sequence the events in a functional-adaptive series that had to occur before the early Eocene primate radiations. I suggest that all of these important adaptive events had to occur at a small body size below 50 g. KEY WORDS small body size; ecology; life-history traits; Soricidae; Microcebus; primate models; primate evolution

An improved understanding of the evolution of gene function at the molecular level may provide significant insights into the origin of biological novelty and adaptation. With the approach of ancestral protein reconstruction, we here address the question of how a dramatically enhanced ribonucleolytic activity and the related antiviral activity evolved in a recently duplicated ribonuclease (eosinophil-derived neurotoxin) gene of higher primates. We show that the mother gene of the duplicated genes had already possessed a weak antiviral activity before duplication. After duplication, substitutions at two interacting sites (Arg-64 [right arrow] Ser and Thr-132 [right arrow] Arg) resulted in a 13-fold enhancement of the ribonucleolytic activity of eosinophil-derived neurotoxin. These substitutions are also necessary for the potent antiviral activity, with contributions from additional amino acid changes at interacting sites. Our observation that a change in eosinophil-derived neurotoxin function occurs only when both interacting sites are altered indicates the importance of complementary substitutions in protein evolution. Thus, neutral substitutions are not simply 'noises' in protein evolution, as many have thought. They may play constructive roles by setting the intramolecular microenvironment for further complementary advantageous substitutions, which can lead to improved or altered function. Overall, our study illustrates the power of the 'paleomolecular biochemistry' approach in delineating the complex interplays of amino acid substitutions in evolution and in identifying the molecular basis of biological innovation.

We demonstrate that the nuclear topological arrangement of chromosome territories (CTs) has been conserved during primate evolution over a period of about 30 million years. Recent evidence shows that the positioning of chromatin in human lymphocyte nuclei is correlated with gene density. For example, human chromosome 19 territories, which contain mainly gene-dense and early replicating chromatin, are located toward the nuclear center, whereas chromosome 18 territories, which consist mainly of genepoor and later replicating chromatin, is located close to the nuclear border. In this study, we subjected seven different primate species to comparative analysis of the radial distribution pattern of human chromosome 18- and 19-homologous chromatin by three-dimensional fluorescence in situ hybridization. Our data demonstrate that gene-density-correlated radial chromatin arrangements were conserved during higher-primate genome evolution, irrespective of the major karyotypic rearrangements that occurred in different phylogenetic lineages. The evolutionarily conserved positioning of homologous chromosomes or chromosome segments in related species supports evidence for a functionally relevant higher-order chromatin arrangement that is correlated with gene-density.

Research has been conducted on the genetically effective population size. The demographic determinants of this size in the population of savannah baboons in southern Kenya have been investigated and the results are reported.

KEY WORDS taste perception; taste coding; sugars; tannins; alkaloids; sodium chloride; primate taste dichotomy In various environments where primates are presently observed, as well as in forests and savannas which have been inhabited by australopithecines and early hominids, there are (or there have been presumably) categories of substances eliciting taste signals associated with stereotyped responses. Such is the case for various soluble sugars of fruits and nectars, attracting consumers, and for several plant compounds in which bitter or strongly astringent properties have a repulsive effect. The occurrence of such classes of tasty substances among natural products appears to be related to the evolutionary trends that shaped primate sensory perception (for detecting either beneficent or potentially noxious substances) in the context of a long history of coevolution between animals and plants. Here, we present original psychophysical data on humans (412 individuals aged 17-59 years) as an analogy with which to test recent evidence from electrophysiology in nonhuman primates (Hellekant et al. [1997] J. Neurophysiol. 77:978-993; Danilova et al. [1998] Ann. N.Y. Acad. Sci. 855:160-164) that taste fibers can be grouped into clusters of 'best-responding fibers' with two more specific clusters, one for sugars and one for quinine and tannins. The collinearity found between human taste responses (recognition thresholds) for fructose and sucrose, as well as for quinine and tannins, is presented and discussed as another evidence of the two-direction evolutionary trend determining taste sensitivity. Salt perception appears to be totally independent of these trends. Accordingly, the appreciation of a salty taste seems to be a recent culturally learned response, and not a primary taste perception. The very existence of primary tastes is discussed in the context of evolutionary trends, past and present. Am J Phys Anthropol 117:342-348, 2002.

Sexual dimorphism is a pervasive phenomenon among anthropoid primates. Comparative analyses over the past 30 years have greatly expanded our understanding of both variation in the expression of dimorphism among primates, and the underlying causes of sexual dimorphism. Dimorphism in body mass and canine tooth size is familiar, as is pelage and 'sex skin' dimorphism. More recent analyses are documenting subtle differences in the pattern of skeletal dimorphism among primates. Comparative analyses have corroborated the sexual selection hypotheses, and have provided a more detailed understanding of the relationship between sexual selection, natural selection, and mating systems in primates. A clearer picture is emerging of the relative contribution of various selective and nonselective mechanisms in the evolution and expression of dimorphism. Most importantly, recent studies have shown that dimorphism is the product of changes in both male and female traits. Developmental studies demonstrate the variety of ontogenetic pathways that can read to dimorphism, and provide additional insight into the selective mechanisms that influence dimorphism throughout the lifetime of an animal. Evidence from the fossil record suggests that dimorphism probably evolved in parallel twice, and the dimorphism in some extinct hominoids probably exceeded that of any living primate. Our advances in understanding the behavioral/ecological correlates of dimorphism in living primates have not improved our ability to reconstruct social systems in extinct species on the basis of dimorphism alone, beyond the inference of polygyny or intense male-male competition. However, our understanding of the behavioral/ecological correlates of growth and development, and of the expression of dimorphism as a function of separate changes in male and female traits, offers great potential for inferring evolutionary changes in behavior over time. Yrbk Phys Anthropol 44:25-53, 2001. KEY WORDS sexual dimorphism; sexual selection; canine teeth; primates

Research has been conducted on the disease risk and its consequences for the host defenses, immune system included. The analysis of the basal white blood cells collected from different primate species have demonstrated that social, ecological and life-history cannot influence host defenses and that the variation in immune defence parameters in primates can be explained by female mating promiscuity.

Major transformations in the skull and masticatory system characterized the evolution of crown anthropoids. To offer further insight into the phylogenetic and arguably adaptive significance of specific primate mandibular loading and kinematic patterns, allometric analyses of metric parameters linked to masticatory function are performed within and between 47 strepsirhine and 45 recent anthropoid species. When possible, basal anthropoids are considered. These results are subsequently integrated with prior experimental and morphological work on primate skull form. As compared to strepsirhines, crown anthropoids have a vertically longer ascending ramus linked to a glenoid and condyle positioned relatively higher above the occtusal plane. Interestingly, anthropoids and strepsirhines do not exhibit different mean ratios of condylar to glenoid height, which suggests that both clades are similar in their ability to evenly distribute occlusal contacts and perhaps forces along the postcanine teeth. Thus, given the considerable suborder differences in the scaling of both glenoid and condylar height, we argue that much of this variation in jaw-joint height is linked to suborder differences in relative facial height due in turn to increased encephalization, basicranial flexion, and facial kyphosis in anthropoids. Due to a more elongate ascending ramus, anthropoids evince more vertically oriented masseters than like-sized strepsirhines. Having a relatively longer ramus and a more medially displaced lateral pterygoid plate, crown anthropoids exhibit medial pterygoids oriented similar to those of strepsirhines, but with a variably longer lever arm. As anthropoid masseters are less advantageously placed to effect transverse movements/forces, we argue that balancing-side deep-masseter activity underlying a wishboning loading regime serves to increase, or at least maintain, transverse levels of jaw movement and occlusal force at the end of the masticatory power stroke. Crown anthropoids are also more isognathic and isodontic than strepsirhines. A consideration of early anthropoids suggests that the crown anthropoid masticatory pattern, i.e., more vertical masseters due to a high condyle as well as greater isognathy and isodonty, occurred stepwise during stem anthropoid evolution. This appears to correspond to a more transverse, and perhaps progressively larger, power stroke across oligopithecids, parapithecids, and propliopithecids. Keywords: jaw adductors; jaw kinematics; jaw loading regimes; jaw joint; occlusion; masticatory biomechanics; functional morphology; allometry

Most of the papers included in this volume are derived from presentations in a symposium on Mammalian Feeding at the 65th Annual Meetings of the American Association of Physical Anthropologists in North Carolina in 1996. The aims of this symposium were to gather together the preeminent researchers on mammalian mastication and document the state of research in that field. The symposium emphasized in vivo studies of mammalian feeding because of a paucity of recent reviews of this field, but included morphometric and modeling papers as well. Subsequently the papers were revised, and were submitted in spring 1998 for publication, pending the outcome of peer review.

Branisella boliviana, from the Late Oligocene of Salla, Bolivia, is the oldest fossil platyrrhine monkey discovered. To date, several fossil specimens of Branisella have been obtained, but most of them are fragmentary dentitions, so the animals craniodental morphology is still obscure. During the 1996 field season a pair of upper and lower jaw fragments and another nearly complete mandible were recovered. These new fossil materials reveal the following morphological features in Branisella: 1) P(super 2) is much smaller than P(super 3,4), whereas P(sub 2) is relatively small but probably sexually dimorphic; 2) the zygomatic arch protrudes smoothly posterolaterally from the maxillary bone, as in extant Callicebus; 3) the mandibular arcade is nearly V-shaped and the symphysial angle, which is formed by the horizontal plane and the anterior face of mandibular symphysis, is about 40 degrees, i.e., it neither leans as far anteriorly as in callitrichines nor does it stand as vertically as Cebus; 4) upper and lower molars wore down rapidly in life, suggesting a herbivorous diet and the possibility of terrestriality; and 5) dental eruptive sequence is the same as in extant Aotus. As a whole, the dentition of Branisella is very similar to that of Proteopithecus from the Late Eocene of Fayum, Egypt, except in the lower canine morphology, suggesting a close phyletic relationship between them. The origin and early diversification of platyrrhine monkeys might have occurred on the African continent before crossing the Atlantic Ocean. Keywords: Branisella; platyrrhine origins; Salla; Late Oligocene; Proteopithecus

Cineradiographic Study of Forelimb Movements During Quadrupedal Walking in the Brown Lemur (Eulomur fulvus, Primates: Lemuridae) Movements of forelimb joints and segments during walking in the brown lemur (Eulemur fulvus) were analyzed using cineradiography (150 frames/sec). Metric gait parameters, forelimb kinematics, and intralimb coordination are described. Calculation of contribution of segment displacements to stance propulsion shows that scapular retroversion in a fulcrum near the vertebral border causes more than 60% of propulsion. The contribution by the shoulder joint is 30%, elbow joint 5%, and wrist joint 1%. Correlation analysis was applied to reveal the interdependency between metric and kinematic parameters. Only the effective angular movement of the elbow joint during stance is speed-dependent. Movements of all other forelimb joints and segments are independent of speed and influence, mainly, linear gait parameters (stride length, stance length). Perhaps the most important result is the hitherto unknown and unexpected degree of scapular mobility. Scapular movements consist of ante-/retroversion, adduction/abduction, and scapular rotation about the longitudinal axis. Inside rotation of the scapula (60 degrees -70 degrees), together with flexion in the shoulder joint, mediates abduction of the humerus, which is not achieved in the shoulder joint, and is therefore strikingly different from humeral abduction in man. Movements of the shoulder joint are restricted to flexion and extension. At touch down, the shoulder joint of the brown lemur is more extended compared to that of other small mammals. The relatively long humerus and forearm, characteristic for primates, are thus effectively converted into stride length. Observed asymmetries in metric and kinematic behavior of the left and right forelimb are caused by an unequal lateral bending of the spinal column. Keywords: scapular movement; shoulder evolution; humeral abduction; primate locomotion

Human growth is discussed from an evolutionary perspective, including the relationship to growth patterns of mammals and primates. Topics include the evolution of the juvenile growth stage in mammals, primate growth patterns, weight growth and skeletal growth in primates, the human adolescent growth spurt, differences between humans and rhesus monkeys in growth velocity, patterns of growth for humans versus other primates, and a philosophy of human growth.

This study tests predicted morphoclines in fingertip morphology among four small-bodied ( KEY WORDS ungulae; tegulae; primate origins; epidermal ridges; hand morphology

The bony labyrinth inside the petrous part of the temporal bone houses the organs of hearing and balance. Being functionally linked with sensory control of body movements and located in a part of the basicranium that is closely associated with the brain, this structure is of great interest in the study of human evolutionary history. However, few aspects of its morphology have been studied in nonhuman primates. This review compares the bony labyrinth of humans with that of the great apes and 37 other primate species based on data newly acquired with computed tomography combined with previous descriptions. With body mass taken into account, consistent differences are found between the size of the semicircular canals in humans, the great apes, and other primates. In particular, the arcs of the anterior and posterior canals are larger in humans than in the African apes. The functional implications of semicircular canal dimensions for registering angular head motion are evaluated in relation to locomotor behavior. Biophysical models, comparative studies, and some neurophysiological experiments all support a link between semicircular canal size and agility, or more specifically the frequency contents of natural head movements, but the evidence on the exact nature of this link is ambiguous. It is concluded that any link between the characteristic dimensions of the human canals and locomotion will be more complex than a simple association with the broad categories of quadrupedal vs. bipedal behavior. The functionally important planar orientations of the semicircular canals are similar in humans and the African apes as well as in many other species. In contrast, other aspects of the human labyrinth differ markedly in shape, following a pattern that seems to reflect the characteristic architecture of the human basicranium. Indeed, it is found that labyrinthine and basicranial shape are interspecifically correlated in the sample, and in most respects the human morphology is consistent with the general trend among primate species. Differences in brain growth and development are proposed as the predominant factor underlying both the unique shape of the human labyrinth as well as the interspecific labyrintho-basicranial correlations. KEY WORDS primates; hominoids; inner ear; semicircular canals; cochlea; locomotion; basicranium

Apolipoprotein(a) [apo(a)] is the distinguishing protein component of lipoprotein(a), a major inherited risk factor for atherosclerosis. Human apo(a) is homologous to plasminogen. It contains from 15 to 50 repeated domains closely related to plasminogen kringle four, plus single kringle five-like and inactive protease-like domains. This expressed gene is confined to a subset of primates. Although most mammals lack apo(a), hedgehogs produce an apo(a)-like protein composed of highly repeated copies of a plasminogen kringle three-like domain, with complete absence of protease domain sequences. Both human and hedgehog apo(a)-like proteins form covalently linked lipoprotein particles that can bind to fibrin and other substrates shared with plasminogen. DNA sequence comparisons and phylogenetic analysis indicate that the human type of apo(a) evolved from a duplicated plasminogen gene during recent primate evolution. In contrast, the kringle three-based type of apo(a) evolved from an independent duplication of the plasminogen gene approximately 80 million years ago. In a type of convergent evolution, the plasminogen gene has been independently remodeled twice during mammalian evolution to produce similar forms of apo(a) in two widely divergent groups of species.

Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor family. Portions of the gene encoding KGF were amplified during primate evolution and are present in multiple nonprocessed copies in the human genome. Nucleotide analysis of a representative sampling of these KGF-like sequences indicated that they were at least 95% identical to corresponding regions of the KGF gene. To localize these sequences to specific chromosomal sites in human and higher primates, we used fluorescence in situ hybridization. In human, using a cosmid probe encoding KGF exon 1, we assigned the location of the KGF gene to chromosome 15q15-21.1. In addition, copies of KGF-like sequences hybridizing only with a cosmid probe encoding exons 2 and 3 were localized to dispersed sites on chromosome 2q21, 9p11, 9q12-13, 18p11, 18q11, 21q11, and 21q21.1. The distribution of KGF-like sequences suggests a role for alphoid DNA in their amplification and dispersion. In chimpanzee, KGF-like sequences were observed at five chromosomal sites, which were each homologous to sites in human, while in gorilla, a subset of four of these homologous sites was identified; in orangutan two sites were identified, while gibbon exhibited only a single site. The chromosomal localization of KGF sequences in human and great ape genomes indicates that amplification and dispersion occurred in multiple discrete steps, with initial KGF gene duplication and dispersion taking place in gibbon and involving loci corresponding to human chromosomes 15 and 21. These findings support the concept of a closer evolutionary relationship of human and chimpanzee and a possible selective pressure for such dispersion during the evolution of higher primates.

To date major divergences that occurred in the primate lineage leading to modern humans and to infer a demographic parameter (effective population size) of the ancestral lineage that existed at each divergence, a maximum likelihood method was applied to autosomal DNA sequence data currently available for pairs of orthologous genes between the human and each of the chimpanzee, gorilla, Old World monkey (OWM), and New World monkey (NWM). A statistical test is carried out to support the assumption that silent substitutions have accumulated in a clock-like fashion over loci between primate taxa or even among sites within a locus. It is shown that the human ancestral lineage became distinct from the NWM 57.5 million years (Myr) ago, the OWM 31 Myr ago, the gorilla 8.0 Myr ago, and the chimpanzee 4.5 Myr ago, and that the effective population size at these divergences was generally much greater than that of modern humans. It is argued that the human ancestral lineage branched off from the NWM and OWM earlier than once thought and that significant demographic changes might have occurred at different evolutionary stages, particularly at the hominid stage.

Two new adapiform primate species from locality 41, Jebel Qatrani Formation, Egypt, are described. The first, here named Wadilemur elegans genus novum species novum (holotype Cairo Geological Museum 42211), consists of a right mandible with [P.sub.3]-[M.sub.3]. The second is assigned to Anchomomys milleri species novum, with a holotype Cairo Geological Museum 42842, that includes the right mandible with lower canine to [M.sub.3]. Both species are allied closely with genera that are known to be from Eocene deposits either in Europe, Tunisia, or the Sultanate of Oman (Arabia), thus enhancing earlier paleomagnetic evidence that locality 41 was deposited in Eocene times.

Fossil crania from quarry L-41, Fayum, Egypt, representing Catopithecus browni, a primate similar in size to callitrichids but with a catarrhine dental formula, provide the geologically earliest record of an anthropoidean skull. Catopithecus had postorbital closure developed to the stage seen in extant anthropoideans, with direct contact between zygomatic plate and maxillary tuber, isolating an anterior orbital fissure from the inferior orbital fissure. The auditory region also resembles that of later anthropoideans: The posterior carotid foramen is placed adjacent to the jugular fossa; a large promontory canal crosses the promontorium; and the annular ectotympanic is fused ventrally to the bulla. The incisors and canines show an assemblage of features found only among modern anthropoideans and adapoids. The face is characterized by a relatively deep maxilla, broad ascending wing of the premaxilla, and long nasal bones, yielding a moderate muzzle similar to that of Aegyptopithecus. The small braincase bears an anteriorly broad frontal trigon and a posteriorly developed sagittal crest. The mandibular symphysis is unfused even in mature adults. The encephalization quotient (EQ) probably falls within the range of Eocene prosimians, much lower than the EQs of Neogene anthropoideans. KEY WORDS Primate evolution, Anthropoidea, Fayum, Neurocranium, Basicranium, Dentition, Paleobiology

We report new evidence that bears decisively on a long-standing controversy in primate systematics. DNA sequence data for the complete cytochrome b gene, combined with an expanded morphological data set, confirm the results of a previous study and again indicate that all extant Malagasy lemurs originated from a single common ancestor. These results, as well as those from other genetic studies, call for a revision of primate classifications in which the dwarf and mouse lemurs are placed within the Afro-Asian lorisiforms. The phylogenetic results, in agreement with paleocontinental data, indicate an African origin for the common ancestor of lemurs and lorises (the Strepsirrhini). The molecular data further suggest the surprising conclusion that lemurs began evolving independently by the early Eocene at the latest. This indicates that the Malagasy primate lineage is more ancient than generally thought and places the split between the two strepsirrhine lineages well before the appearance of known Eocene fossil primates. We conclude that primate origins were marked by rapid speciation and diversification sometime before the late Paleocene.

The ZNF91 gene family, a subset of the Kruppel-associated box (KRAB)-containing group of zinc finger genes, comprises more than 40 loci; most reside on human chromosome 19p12-p13.1. We have examined the emergence and evolutionary conservation of the ZNF91 family. ZNF91 family members were detected in all species of great apes, gibbons, Old World monkeys, and New World monkeys examined but were not found in prosimians or rodents. In each species containing the ZNF91 family, the genes were clustered at one major site, on the chromosome(s) syntenic to human chromosome 19. To identify a putative 'founder' gene, >20 murine KRAB-containing zinc finger protein (ZFP) cDNAs were randomly cloned, but none showed sequence similarity to the ZNF91 genes. These observations suggest that the ZNF91 gene cluster is a derived character specific to Anthropoidea, resulting from a duplication and amplification event some 55 million years ago in the common ancestor of simians. Although the ZNF91 gene cluster is present in all simian species, the sequences of the human ZNF91 gene that confer DNA-binding specificity were conserved only in great apes, suggesting that there is not a high selective pressure to maintain the DNA targets of these proteins during evolution.

Analysis of the whole skull of a platyrrhine monkey fossil found in Chilean Andes, together with phylogenetic analysis of the more developed anthropoid primates, gives an insight into platyrrhine interrelationships. Radioisotopic experiments date the skull to Early Miocene age. The New World monkey's evolution includes platyrrhine morphotypes modification and a likely African origin.

The study of the early anthropoids or anthropoideans from the Oligocene badlands of the Fayum Province, Egypt, covers the greater part of this century. This review discusses the successive stages of our knowledge of these animals, which have become the oldest well understood kinds of higher primates or anthropoideans. The study of the first finds, made early in the century, is reviewed and the various interpretations of these scanty remains are discussed. All initial discussions were based on only four specimens. Essentially all of the early rankings made by authors who, in many cases, had not seen the actual specimens were incorrect. Nevertheless it was realized that these Fayum primates were somehow the earliest relatives of apes and monkeys then known. Prominent scholars questioned whether one of these, Apidium, was even a primate. At the end of the 1950s two specimens, found at the beginning of the century, were located at the American Museum of Natural History. Their description kindled new interest in the Fayum primates and established that they showed cranial characters of higher primates. Beginning in 1961 a sequence of four periods of development in the study of these important ancient primates began. The first was a series of eight expeditions from Yale University conducted from 1961 to 1968. These cooperative projects conducted with the Geological Survey and Mining Authority of Egypt (EGSMA) increased the number of primate specimens from six or eight to over 500. These discoveries led to the description of new species as well as reports on the first limb elements and cranial remains. After this phase came a period when the desert Fayum was closed to exploration and publications were concerned mainly with continued description of the new finds. The third major period of research that is outlined here, between 1977 and 1989, came with renewed field work in Egypt now carried out cooperatively between Duke University and EGSMA. The research on Fayum primates in this period was greatly expanded, as is explained in this paper, because: 1) new techniques enabled the recovery of extensive collections of postcranial elements as well as skulls and facial crania, which made possible revisions of both anatomy of the propliopithecids and parapithecids; 2) an international interdisciplinary team published extensively on the background context for the primates including studies on environment, dating, and geological setting; and 3) prosimians in addition to the basal Anthropoidea were found. Since 1990 research on Fayum primates has been expanded even more to include a larger number of researchers, many trained through field work at the various Fayum localities, and although important Oligocene finds continue to be made, a whole new world of Eocene anthropoidean and prosimian primates has been discovered there. KEY WORDS Fayum Province, Egypt, Oligocene, Anthropoideans, Dawn apes, propliopithecids, parapithecids, Apidium, Aegyptopithecus, Parapithecus, Propliopithecus, Afrotarsius, primate anatomy, primate behavior, paleoecology

There has been a substantial improvement in the understanding of the evolution of human life cycle with the initiation of the comparative methodology of life history into anthropology and research on bone and dental development indicating the importance of fossil record. This suggests the reliance of human strategy on abundant energy sources and low mortality and the concept of the parallel evolution of rate of growth and aging with brain size. Early Homo erectus grew faster than living humans and was slow in adolescent growth.

More than 240 milk teeth of Victoriapithecus macinnesi, representing all elements of the deciduous dentition, are described. Their morphology is intermediate between that of hominoids and cercopithecids. Unlike colobine and cercopithecine milk teeth, Victoriapithecus d[p.sup.3]s, d[p.sup.4]s, and at least 7 (14%) d[p.sub.4]s lack transverse distal loph(id)s and are not bilophodont. Victoriapithecus also differs from cercopithecids in having less elongated deciduous premolars, a d[p.sup.3] metacone set mesial to a very small hypocone, a d[p.sup.4] crista obliqua, and a d[p.sub.4] hypoconulid. The deciduous canines and incisors of Victoriapithecus are like those of other cercopithecids in having an uneven distribution of enamel around a compressed (rather than cylindrical) root, but differ from cercopithecids and resemble hominoids in being more elongated. Since Colobinae and Cercopithecinae share features of the deciduous dentition that are derived relative to Victoriapithecus and hominoids, extant Old World monkeys are interpreted as representing the sister-taxon of the middle Miocene cercopithecoids. Due to a dramatic increase in the number of deciduous teeth found at Maboko Island, juvenile individuals represent a much larger proportion of recently excavated Victoriapithecus collections than is true of pre-1987 assemblages which mainly derive from sediment first excavated during the 1930s and 1940s. Age distribution differences between pre- and post-1987 samples indicate that paleontological collection procedures were more important than taphonomic biases in determining the paleodemographic profile of the Maboko fossils. Since the Victoriapithecus assemblage from Maboko is strikingly similar to that of fossil Theropithecus oswaldi from Olorgesailie in terms of the large number of specimens and high representation of juvenile and infant individuals, the latter can no longer be viewed as unique among cercopithecoid fossil assemblages. Rather than being related to a specific cause of death, such as selective hunting of T. oswaldi by Homo (Shipman et al. [1981] Curr. Anthropol. 22:257-268), the large number of cercopithecoids at both sites is attributed to the fact that both assemblages represent excavated samples and that the preferred habitats of the extinct monkeys were probably at or near the site of deposition. The greater number of young adult male than female canines in the apparently attritional Maboko Bed 5 assemblage, indicate that the social organization of V. macinnesi may have been similar to that of modern macaques, with males migrating out of their natal group and suffering higher death rates than females at puberty. KEY WORDS: Primate evolution, Systematics, Paleontology, Paleodemography, Taphonomy, Paleoanthropology, Deciduous dentition, Cercopithecoid monkeys, Miocene, Victoriapithecus, Theropithecus, Maboko, Olorgesailie

The use of three somatic cell hybrid panels helps assign sixteen isozyme markers to the chromosome complement of Ateles paniscus chamek, the neotropical primate. The species exhibits a few conserved ancestral syntenic relations despite the rearrangement of many syntenic groups and homeologies with humans in limited regions. A comparison of the gene maps of other primates and mammalian orders helps study the genome evolution in Ateles panisus chamek.

Observation of the vestibular system of living primates and early hominids reveals that the bony labyrinth morphology explains the locomotor property and phylogenetic relationships of early hominids. The fossil hominids of Homo erectus explain the modern human semicircular canal morphology, which suggests its obligatory bipedal behavior. Australopithecus africanus exhibits a locomotor behavior of facultative bipedalism and arboreal climbing.

An examination of previous morphological and molecular studies of strepsirhine systematics suggests a conflict between the two types of data. Cladistic analyses of morphological data have indicated that the Malagasy primate family Cheirogaleidae is the sister taxon of the Afro-Asian lorisiforms and that together, cheirogaleids and lorisiforms comprise a monophyletic clade that excludes the Malagasy lemuriforms. Molecular studies, on the other hand, have consistently found that cheirogaleids and lemuriforms together are monophyletic to the exclusion of lorisiforms. Both types of studies, however, have suffered from methodological weaknesses: the morphological studies looked at too few characters and the molecular studies looked at too few taxa. This study examines a large and diverse morphological data set as well as molecular data from a comprehensive sample of strepsirhine taxa. The data sets are considered independently and jointly. When they are analyzed independently, the morphological data give weak support, and the molecular data strong support, to the hypothesis of Malagasy primate monophyly. When the two data sets are combined in a single analysis, the results are decisive. The 'total evidence' approach yields compelling support to the hypothesis that cheirogaleids and remaining Malagasy lemuriforms comprise a monophyletic assemblage that excludes lorisiforms. [C] 1994 WIley-Liss, Inc.

Established theories and views regarding the course and timing of the evolution of early primates are being challenged by newly discovered fossil primate specimens. The questions raised by these recent discoveries mirror the many problems created by low sampling levels of the primate fossil record, such as theoretical uncertainties and underestimation of times of primate origin. The discoveries, for instance, have raised the possibility of links between certain Palaeocene Pleisadapiformes genera and Dermoptera. Dental evidence of the genus Algeripithecus also increased the age of earliest simians by 10 million years.

Relevant segments of the C4-CYP21 region of the chimpanzee, gorilla, pigtail macaque and orangutan were sequenced to determine the time of occurence of primigenial C4-CYP21 duplication in primates and the mechanism involved in this process. Results revealed that the duplication breakpoint in primates are in the same location as in humans. In addition, sequences surrounding paralogous genes have a greater similarity compared with those flanking orthologous genes in dissimilar species. These indicate that primigenial duplication took place through nonhomologous recombination and before apes diverged from Old World Monkeys over 23 million years ago.

Recent excavations from the middle Miocene deposits in the Maboko Formation yielded an undistorted and nearly complete juvenile mandible of Kenyapithecus africanus. This specimen was compared to thejuvenile and adult mandibles of Proconsul, Sivapithecus, Hylobates, Pongo, Gorilla, Pan and Homo to determine evolutionary relationships and mandibular adaptations in K. africanus. The results showed that K. africanus diverged after Proconsul and Griphopithecus but prior to the last common ancestor of Sivapithecus, extant great apes and humans. Specialized anterior dentition suggested an increased exploitation of hard fruits and nuts.

Four new repeat elements found in primate genomes are presented. Two of these, Alu and Xba, are human-specific, while one Alu repeat is gorilla-specific. The fourth, an enolase pseudogene, was detected in human, chimpanzee, gorilla, orangutan and baboon genomes. Calculations based on standard molecular clock concepts showed that the enolase pseudogene is 14 million years old, a figure which is not consistent with the divergence of Old World monkeys and the homonid lineage. Therefore, the mutation rates of pseudogenes may vary from species to species.

Hominoid primates lived in Africa, Asia and Europe between 10 and 20 million years ago, but the evolutionary relationships between them and to humans and modern apes is not clear. Morphological and molecular studies have not even clearly answered the question whether gorillas or chimpanzees are closer evolutionary relatives to humans though they have established that all three are closer to each other than to orangutans. New paleoecological evidence may augment fossil discoveries to help explain these relationships notwithstanding the lack of adequate fossil records.

A nearly complete cranium of Ignacius graybullianus provides increased understanding of the cranial anatomy of Plesiadapiformes. In nearly all details of cranial anatomy, Ignacius differs markedly from primates. USNM 421608 exhibits a long tapering snout, small widely spaced orbits, and a complete lack of postorbital process or bar. Large olfactory bulbs are inferred from the wide interorbital space. The marked flare of the zygomatic arches suggests that Ignacius possessed large and powerful temporal muscles. The basicranial region is particularly well preserved and reveals a distinct suture between the petrosal bone and an entotympanic bulla. This suture is visible on both the left and right sides of the skull and dispels the hypothesis that Ignacius and, by inference, other Plesiadapiformes share the primate synapomorphy of a petrosal bulla. To test the phylogenetic position of Ignacius, cranial characters were identified and scored for Ignacius, Plesiadapis, Cynocephalus, and a number of primates, bats, and scandentians. Two erinaceomorph insectivores were also included to allow the assessment of archontan monophyly. These characters were incorporated into a maximum-parsimony analysis to determine the phylogenetic position of Plesiadapiformes. There are several important phylogenetic conclusions that can be inferred from this analysis: 1) Ignacius and Plesiadapis make up a monophyletic clade; 2) Plesiadapiformes may be the sister group of Dermoptera; 3) Scandentia, not Plesiadapiformes, is the sister group of Primates; and 4) Primates, plesiadapiforms, bats, colugos, and scandentians may not form a monophyletic clade Archonta. Consequently, the taxon Archonta is in need of review.

An investigation was conducted to determine the sequence and map location of the KGF gene, as well as to search for other KGF-related sequences. The results showed that KGF consists of three exons and two introns located on chromosome 15. Sequence analysis showed that a portion of the gene is amplified and dispersed within the human genome. Homology searches showed the presence of KGF sequences in other primates, the patterns of which suggest the ancestral KGF amplified and dispersed after the subsequent divergece of orangutans from African apes but before the divergence of humans, chimpanzees and gorillas.

The adaptive radiation of modern New World monkeys unfolded as the major lineages diversified within different dietary-adaptive zones predicated upon a fundamentally frugivorous habit. The broad outlines of this pattern can be seen in the fossil record, beginning in the early Miocene. Cebids are obligate frugivorous predators. The smallest forms (Cebuella, Callithrix) are specialized exudativores, and the largest (cebines) are seasonally flexible omnivores, feeding particularly on insects (Saimiri) or 'hard' foods, such as pith and palm nuts (Cebus), when resources are scarce. The smaller-bodied atelids (Callicebus, Aotus) may use insects or leaves opportunistically, but pitheciins (saki-uakaris) specialize on seeds as their major protein source. The larger atelines (Alouatta, Brachyteles) depend on leaves or on ripe fruit (Ateles). Locomotion, body size, and dietary adaptations are linked: claws and small body size opened the canopy-subcanopy niche to callitrichines; climbing and hanging, the fine-branch setting to the atelines; large size and strength, semiprehensile tails, and grasping thumbs, the extractive insectivory of Cebus; deliberate quadrupedalism, the energy-saving transport of folivorous Alouatta. Body size increases and decreases occurred often and in parallel within guilds and lineages. Conventional dietary categories, particularly frugivory, are inadequate for organizing the behavioral and anatomical evidence pertinent to evolutionary adaptation. Related models of morphological evolution based on feeding frequencies tend to obfuscate the selective importance of 'critical functions,' responses to the biomechanically challenging components of diet that may be determined by a numerically small, or seasonal, dietary fraction. For fossils, body size is an unreliable indicator of diet in the absence of detailed morphological information. More attention needs to be given to developing techniques for identifying and quantifying mechanically significant aspects of dental form, the physical properties of primate foods, their mode of access, and the cycles of availability and nutritional value.

The relationship between body size and feeding ecology is well established for primates. It is argued that the evolutionary history of modern New World monkeys and, in particular, the path to attainment of current body size is significant in understanding the similarities and differences between dietary strategies and other ecological parameters of similar-sized monkeys. Current interpretations of New World monkey evolutionary relationships are reviewed. Based on a synthesis of available body weights and the assumption that the earliest New World monkeys weighed close to 1 kg, similar to modern Aotus and Callicebus, predicted patterns of body size change in each lineage are given. Restrictions on directions of body size change in primates are discussed, and it is shown that 'Stanley's Rule' offers a good explanation for differing body size ranges in New and Old World anthropoids. Predicted ecological correlates to body size drawn from the mammalian literature are offered and tested using data on New World monkeys, which show some concurrence and several interesting departures from predicted patterns. Sexual dimorphism in body weight of New World monkey species is reviewed, based on the new summary of body weight data given.

The orbitotemporal venous sinuses accompany the intracranial branches of the stapedial artery. These sinuses are large in primitive primates and drain the extensive territories supplied by the stapedial artery as well as the brain. The orbit is drained by a wide cranio-orbital sinus which empties into the postglenoid emissary vein. Also emptying into the postglenoid vein is the petrosquamous sinus. The latter diverts cerebral blood from the transverse sinus and also drains the temporalis muscle. Emptying into both the cranio-orbital and petrosquamous sinuses are meningeal tributaries, which drain the cranial side wall and the dura mater. The relatively small sinus communicans runs in the angle between the petrosal bone and the cranial side wall. It commences at the postglenoid vein and connects the distal end of the petrosquamous sinus to the pterygoid venous plexus. In humans, the orbitotemporal sinus system is greatly modified. Its remnants persist for the most part as 'middle meningeal veins.' The system no longer drains the orbit, the temporal fossa, or the brain. The petrosquamous sinus becomes attenuated or obliterated along part or all of its length. The postglenoid vein vanishes. The cranio-orbital sinus is reduced in diameter and its connection to the orbit is feeble or absent. During development, the posterior end of the cranio-orbital sinus migrates inferiorly along the sinus communicans. In most individuals, this migration ceases at the foramen spinosum, site of the emissary vein of the sinus communicans. Meningeal tributaries are relatively large in humans, and drain principally into the cranio-orbital sinus or sphenoparietal sinus. The sphenoparietal sinus is an evolutionary novelty restricted to hominoids and is frequently developed in only Homo and Pongo.

Southern blot hybridization, in situ hybridization and molecular cloning were used to analyze DNA from leukemia cells characterized by a complex translocation. A breakpoint at 17q21 was seen to be frequently involved in complex 9;22 translocations with cloned sequences on chromosome 17 at band q21 found to be repeated in normal cells. It was presumed after comparison with other primate species, that an inversion in chromosome 17 during evolution was responsible for the splitting of the clusterof repeat units in normal human cells.

The alpha-repeat is a class of noncoding DNA in primates that undego frequent rearrangements. The human chromosomal alpha-repeats have been shown to possess a pattern of homogenization between non-homologous chromosomes. The alpha-repeats present in the chimpanzee chromosome were studied. The results showed that chimpanzee alpha-repeats also possess a pattern of pairwise homogenization. Although the observed patterns were similar between species, their origins are different. The results indicate the occurence of a concerted sequence evolution in one or both species during or after their divergence.

Reanalysis of the sample of Miocene Hominoidea from Spain, together with the entire sample of European Miocene Hominoidea, has revealed a number of distinctive traits among the specimens from the early Vallesian locality of Can Ponsic (Crusafont and Hurzeler, 1969; Crusafont and Golpe, 1973; Hartenberger and Crusafont, 1979; Agusti et al., 1984, 1985). The Can Ponsic sample, while sharing characteristics with other samples of Dryopithecus from Europe, is sufficiently distinctive to form the basis for a new species. Characteristic of the new species are a distinctive lower molar occlusal morphology, large, broad upper molars, and very high crowned upper central incisors with well-developed lingual pillars. The new species shares characteristics with Dryopithecus laietanus, the only other species of the genus in Spain, and lacks derived features of non-Spanish Dryopithecus. Four species of Dryopithecus are now known (Begun, 1987, 1988a, and in preparation). Their distribution and morphology have significant implications for the biogeography and phylogeny of this early great ape genus.