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The development, function, and integration of morphological characteristics are all hypothesized to influence the utility of traits for phylogenetic reconstruction by affecting the way in which morphological characteristics evolve. We use a baboon model to test the hypotheses about phenotypic and quantitative genetic variation of traits in the cranium that bear on a phenotype's propensity to evolve. We test the hypotheses that: 1) individual traits in different functionally and developmentally defined regions of the cranium are differentially environmentally, genetically, and phenotypically variable; 2) genetic covariance with other traits constrains traits in one region of the cranium more than those in others; 3) and regions of the cranium subject to different levels of mechanical strain differ in the magnitude of variation in individual traits. We find that the levels of environmental and genetic variation in individual traits are randomly distributed across regions of the cranium rather than being structured by developmental origin or degree of exposure to strain. Individual traits in the cranial vault tend to be more constrained by covariance with other traits than those in other regions. Traits in regions subject to high degrees of strain during mastication are not any more variable at any level than other traits. If these results are generalizable to other populations, they indicate that there is no reason to suppose that individual traits from any one part of the cranium are intrinsically less useful for reconstructing patterns of evolution than those from any other part. Am J Phys Anthropol 143:1-12, 2010. KEY WORDS evolvability; heritability; constraint; homoiology; phylogenetic analysis DOI 10.1002/ajpa.21341

The hybridization in baboon subspecies shows compatible genes for many different physical and behavioral traits. A careful look at how cooperative viability is maintained while complex adaptive traits evolve and populations differ leads us to question the validity of evolution.

Numerous studies have detected significant contributions of genes to variation in development, size, and shape of craniofacial traits in a number of vertebrate taxa. This study examines 43 quantitative traits derived from lateral cephalographs of 830 baboons (Papio hamadryas) from the pedigreed population housed at the Southwest National Primate Research Center. Quantitative genetic analyses were conducted using the SOLAR analytic platform, a maximum-likelihood variance components method that incorporates all familial information for parameter estimation. Heritability estimates were significant and of moderate to high magnitude for all craniofacial traits. Additionally, 14 significant quantitative trait loci (QTL) were identified for 12 traits from the three developmental components (basicranium, splanchnocranium, and neurocranium) of the craniofacial complex. These QTL were found on baboon chromosomes (and human orthologs) PHA1 (HSA1), PHA 2 (HSA3), PHA4 (HSA6), PHA11 (HSA12), PHA13 (HSA2), PHA16 (HSA17), and PHA17 (HSA13) (PHA, P. hamadryas; HSA, Homo sapiens). This study of the genetic architecture of the craniofacial complex in baboons provides the groundwork needed to establish the baboon as an animal model for the study of genetic and nongenetic influences on craniofacial variation.

Primate evolutionary studies rely significantly on dental variation given the large role that teeth play in how an organism interacts with its environment (animal and plant) and conspecifics. Variation in cusp size has been shown to vary among primate taxa, although most studies to date focused on extant and extinct hominoids. Here we test the assumed hypothesis that a significant proportion of this variation in baboons is due to the additive effects of genes. We perform quantitative genetic analyses on variation in two-dimensional (2-D) mandibular molar cusp size in a captive pedigreed breeding population of baboons (Papio hamadryas) from the Southwest National Primate Research Center. These analyses show that variation in cusp size is heritable and sexually dimorphic. Additionally, we tested for genetic correlations between cusps on the same crown, between morphological homologues along the tooth row, and between cusp area and crown buccolingual width. We find that four of the six cusp pairs on the first molar have a genetic correlation of one, save for the metaconid--hypoconid and entoconid--hypoconid, which are not statistically different from zero. The second and third molars have lower genetic correlations, although the metaconid--hypoconid correlation is similarly estimated at zero and the entoconid--protoconid correlation is estimated to be one. This cross pattern of genetic and no genetic correlation does not immediately accord with the known pattern of development and/or calcification. We propose two explanative hypotheses. KEY WORDS dentition; dental variation; quantitative genetics; Papio; evolution; primate

Within a population, only phenotypic variation that is influenced by genes will respond to selection. Genes with pleiotropic effects are known to influence numerous traits, complicating our understanding of their evolution through time. Here we use quantitative genetic analyses to identify and estimate the shared genetic effects between molar size and trunk length in a pedigreed, breeding population of baboons housed at the Southwest National Primate Research Center. While crown area has a genetic correlation with trunk length, specific linear measurements yield different results. We find that variation in molar buccolingual width and trunk length is influenced by overlapping additive genetic effects. In contrast, mesiodistal molar length appears to be genetically independent of body size. This is the first study to demonstrate a significant genetic correlation between tooth size and body size in primates. The evolutionary implications are discussed. KEY WORDS primate evolution; pleiotropy; quantitative genetics; Papio hamadryas; dental variation

Fecal steroid analysis was used to examine the effects of seasonal, reproductive, and social factors on female testosterone (T) in a group of free-ranging hybrid baboons in the Awash National Park of Ethiopia. The results indicate that the females had elevated T during pregnancy and during the wet season relative to other periods and also that female dominance rank was positively related to T measures.

Analysis of steroid profiles for a wild population of baboons from infancy through reproductive maturation, obtained by noninvasive fecal analyses, was presented. Results demonstrate the presence of individual endocrine variability, which could have important consequences for the timing of sexual maturation and subsequently for individual reproductive success.

Historically, two different numbering systems have been used to describe the baboon and macaque karyotypes. However, G-banding studies and, more recently, fluorescence in situ hybridization results have shown that the two karyotypes are virtually identical. To confirm this hypothesis, cytogenetic analysis of an unusual animal, a rheboon, was undertaken. The rheboon reported here, an 18-year old male, is the only long-term survivor of 26 pregnancies resulting from matings between female baboons (Papio hamadryas) and male rhesus macaques (Macaca mulatta). A G-banded karyotype was prepared from the rheboon and compared with the karyotypes of the two parental species. Spectral karyotyping (SKY) was carried out on the rheboon chromosomes, and the results were compared with SKY studies reported for the baboon and with CISS (chromosome in situ suppression) studies in the rhesus macaque. No differences were detected in any of the rheboon's pairs of autosomes, reinforcing the apparent identity of the two parental karyotypes. Based on these results, we argue that a single karyotyping system should be adopted for the two species. Fertility studies were initiated to determine if the rheboon is sterile, as are most hybrid animals. Two semen ejaculates were devoid of sperm. A testicular biopsy revealed hypoplasia of the seminiferous tubules with few Leydig cells and large lumena. Meiotic arrest occurred during meiosis I, resulting in absence of mature spermatozoa. Thus, the testicular and meiotic findings in the rheboon were similar to those observed in other hybrids, even though the parental karyotypes appear identical. Am J Phys Anthropol 110:119-127, 1999.

A novel polymerase chain reaction (PCR) primer pair was used to analyze the frequency of insertion of the first described, nonhuman, baboon-specific Alu repetitive element in populations from the Papio hamadryas anubis and the Papio hamadryas hamadryas subspecies, and from a number of anubis-hamadryas hybrids. The Alu insertion is found in intron 7 of the baboon lipoprotein lipase (LPL) gene. Each of the populations had different frequencies for the insertion, and the hybrids examined had a frequency intermediate to that of the parental populations. All hybrids and all P. h. anubis groups except the group of anubis sampled in 1973 exhibited higher-than-expected heterozygosity, while P. h. hamadryas and 1973 P. h. anubis showed lower-than-expected heterozygosity, supporting behavioral and other genetic observations of greater anubis outbreeding relative to hamadryas. This may include asymmetric introgression of the Alu insertion from hamadryas to the anubis population due to hybridization. KEY WORDS primate; evolution; Alu; polymorphism; insertion; gene flow; hybridization; hybrid zone

The genes for testis-specific protein Y (TSPY) were sequenced from chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla), orangutan (Pongo pygmaeus), and baboon (Papio hamadryas). The sequences were compared with each other and with the published human sequence. Substitutions were detected at 144 of the 755 nucleotide positions compared. In overviewing five sequences, one deletion in human, four successive nucleotide insertions in orangutan, and seven deletions/insertions in baboon sequence were noted. The present sequences differed from that of human by 1.9% (chimpanzee), 4.0% (gorilla), 8.2% (orangutan), and 16.8% (baboon), respectively. The phylogenetic tree constructed by the neighbor-joining method suggests that human and chimpanzee are more closely related to each other than either of them is to gorilla, and this result is also supported by maximum likelihood and strict consensus maximum parsimony trees. The number of nucleotide substitutions per site between human and chimpanzee, gorilla, and orangutan for TSPY intron were 0.024, 0.048, and 0.094, respectively. The rates of nucleotide substitutions per site per year were higher in the TSPY intron than in the TSPY exon, and higher in the TSPY intron than in the ZFY (Zinc Finger Y) intron in human and apes. KEY WORDS TSPY gene, Phylogenetic relationship, Rate of nucleotide substitutions.

Yellow baboons (Papio hamadryas cynocephalus) from Mikumi National Park, Tanzania were studied for polymorphisms in nuclear DNA. The study population consists of four social groups that inhabit overlapping home ranges and exchange males. As a result, these groups are considered to be members of a single interbreeding population. Human DNA clones were used as probes to screen five loci (AT3, REN, HEXB, VIM, and APOB) for restriction fragment length polymorphisms (RFLP). A total of 14 polymorphisms, at least one at each locus, was detected in a panel of 27 baboons tested using six restriction enzymes for each locus. Eleven of these RFLP systems have average heterozygosity values greater than 0.40. This initial screening demonstrates that human DNA clones can be used to detect significant numbers of informative DNA polymorphisms in single-copy nuclear genes of this species and suggests that the average proportion of nucleotides polymorphic across nuclear loci in this population may be between 1.0% and 1.3%.

The article discusses about the first reported case of a baboon with trisomy of chromosome 17.

Low levels of polymorphism on the Y chromosome of Saudi-Arabian hamadryas baboons, Papio hamadryas hamadryas are reported. Low effect population size of paternal genes due to polygyny and female-biased adult sex ration is a potential reason for low Y chromosome variation in Arabian hamadryas.

The CNS neurotransmitters dopamine, serotonin and norepinephrine play important roles in the control and expression of behavior. Dopamine is associated with arousal and reward seeking, and norepinephrine with anxiety. Serotonin acts to inhibit behavior, including impulsive aggression. We measured metabolites of these neurotransmitters in the cerebrospinal fluid of 186 pedigreed baboons (Papio hamadryas) drawn from the multigeneration colony maintained at the Southwest Foundation. Quantitative genetic analyses were performed using univariate models, with age, sex, body weight and subspecies as covariates. Individual variation is significantly influenced by genetic variation. The estimated heritability ([h.sup.2]) of HVA (metabolite of dopamine) is 0.34 (p [is less than] 0.03), [h.sup.2] of MHPG metabolite of norepinephrine) is 0.32 (p [is less than] 0.03) and [h.sup.2.] of 5HIAA (metabolite of serotonin) is 0.42 (p [is less than] 0.014). The ratio of 5HIAA/HVA, which may be a better indicator of behavioral tendencies than either HVA or 5HIAA alone, has estimated [h.sup.2] of 0.46 (p [is less than] 0.005). Data from humans and other mammals implicates these neurotransmitters in the control of various behaviors. Field studies show that CSF levels of these neurotransmitters vary across subspecies of baboons that differ in fundamental aspects of social behavior. Our data indicate Papio can be used as a model for genetic studies of individual variation in neurochemistry and behavior. Partial support was provided by a Southwest Foundation Forum grant to A.G.C. and NIH grant P51-RR13986 to J.R.

The use of feces as source material for genetic analyses of wild primate populations continues to increase. However, past research has been hampered by the necessity of using markers with variable amplification success, unknown linkage relationship, or too few easily distinguishable alleles. Additionally, low quantities and poor quality of DNA from feces contribute to higher genotyping error. We address these problems first by developing an extraction protocol to increase total DNA yield and quality. We describe a modified Qiagen tissue protocol that yields total DNA with mean yield 165.4 ng/ul (range 21-620 ng/ul). Initial results show 83.5% success in amplifying fecal samples from wild Gombe Stream baboons. To develop a panel of microsatellites ideal for analysis using fecal DNA, we chose from among 334 human microsatellites used in the baboon linkage map, using four criteria: 1) consistent, simultaneous amplification of both alleles in heterozygotes; 2) minimum of 4 alleles; 3) tetranucleotide repeats; 4) mapped to separate baboon chromosomes, or at least 50 cM apart on the same chromosome. We genotyped 13 such markers in an initial sample of 30 olive baboons (Papio hamadryas anubis) from Gombe Stream National Park, Tanzania. Markers are characterized by mean expected heterozygosity of 0.727 (range 0.620-0.834), mean number of alleles 5.8 (range 4-10), and frequency of allelic dropout across all markers of 0.017 (per marker range 0.000-0.077). We compared allele frequencies between Gombe and 51 SFBR olive baboons originally from southern Kenya. We found significant differences at five of 12 loci (Kolmogorov-Smirnov Z-test, p

Endogenous retroviruses (ERs) are vertically transmitted viral genetic elements that are ubiquitous among vertebrates. Hundreds to thousands of copies ate known to persist in all anthropoid genomes examined to date; however, attempts to quantify particular ERs within and/or between lineages have tested few individuals. This study reports the first attempt to quantify a specific ER, baboon endogenous virus (BaEV), within and between natural baboon (Papio hamadryas ssp.) populations using quantitative real-time PCR methods. Results show that considerable BaEV copy number heterogeneity exists among individuals, both within and between populations. Analyses of inheritance patterns indicate that BaEV conforms to a pattern of maternal inheritance previously observed for ERs in other organisms. Insertion site data confirm a proviral integration shared among the four baboon forms tested, indicating a long term, vertically transmitted presence in the Papio genome. Most importantly, the increasing numbers of average BaEV copies maintained by non-hamadryas, hamadryas and gelada baboons, respectively, appear to be a function of the progressively greater degrees of inbreeding observed in each of these primate taxa. This finding represents the first example in primates (and, more generally, in mammals and vertebrates) relating ER dynamics to social structure. Funded by NSF grants #BCS-0087329 and #BCS-9615150, the Wenner-Gren Foundation, and the Sigma-Xi Foundation.

Though it is well known that both genes and advancing age contribute to risk of low bone mass and osteoporosis, geno-type-by-age (GxA) effects on variation in this risk are little understood. We conducted statistical genetic analyses of DEXA-acquired areal bone mineral density (aBMD) measures in the spine, radius, and ulna in 692 pedigreed baboons (Papio hamadryas) to identify GxA effects in this nonhuman primate model for agerelated changes and pathology in bone. We modeled GxA interaction for aBMD by defining the additive genetic component of the variance as a function of age. We also modeled the genetic correlation between relative pairs at different ages as an exponential decay function across age values. Through numerical maximization, we simultaneously estimated these GxA interaction terms plus the mean effects of sex, body weight, crown-rump length, and spinal arthritis severity, on each measure of aBMD. Likelihood ratio tests disclose GxA effects in the spine and ulna, but not in the radius. Genetic variance decreases with age in the spine (p=0.000783, anterior-posterior projection; p=0.002432, lateral projection). Genetic correlation between aBMD at different ages differed significantly from 1.0 in the spine (p=0.028354, lateral projection) and in the ulna (p=0.000194). These results imply that the magnitude of genetic effects changes with age, as do the genes or suite of genes involved. Because the radius bears more weight (load) during baboon locomotion than either the spine of the ulna, we postulate that non-genetic effects related to functional biomechanics may obscure/override GxA interactions on BMD in the radius.

The differential regulation of baboon pulmonary surfactant SP-A1 and SP-A2 genes during development and by CAMP has been studied. Pulmonary surfactants reduce alveolar surface tension and prevent alveolar collapse during air exhalation. Baboon genes were used in the study due to their similarities with human hSP-A and bSP-A genes along with the difficulty of obtaining third-trimester human fetal lung tissues. Type II cells in primary culture were transfected with fusion genes made up of 1,000 bp of 5'-flanking DNA. Their capacity to foster cAMP induction of SP-A promoter activity was then investigated.