Kinda baboons (Papio kindae) and grayfoot chacma baboons (P. ursinus griseipes) hybridize in the Kafue river valley, Zambia
ABSTRACT The ranges of small kinda (Papio kindae) and much larger grayfooted chacma (P. ursinus griseipes) baboons adjoin in the Kafue National Park, Zambia. In a visual survey of baboons at 48 sites in the Kafue River drainage we found that, contrary to previous reports, groups at the species interface near the town of Ngoma are phenotypically diverse and presumably formed by multigenerational hybridization. Mitochondrial and/or Y-chromosome genetic markers from fecal samples (N=164) collected at 29 sites support this conclusion. Groups with phenotypic signs of a history of hybridization also had taxon-specific mitochondria and Y-haplotypes from both parental species. Although the distribution of mitochondrial haplotypes largely mirrored that of external phenotypes, a significant proportion of male specimens from grayfoot as well as hybrid groups carried kinda Y-chromosomes, and kinda Y-chromosomes were involved in all observed cases of mitochondrial/Y-chromosome discordance. These observations are consistent with, though they do not prove, a population history in which the range of chacmas and the hybrid zone have advanced at the expense of the kinda range. They also suggest that, unexpectedly, kinda male×chacma female matings are much more common than the reciprocal cross in the ancestry of hybrids. We suggest that distinctive male kinda behavior and the "juvenile" appearance of kinda baboons of both sexes, perhaps combined with obstetric difficulties of a small kinda female carrying the large offspring of a chacma male, may account for this bias.
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ABSTRACT: Introgressive hybridization may cause substantial discordances among phylogenies based on different genetic markers. Such discordances have been found in diverse mammal species including primates. A recent study of mitochondrial DNA (mtDNA) revealed several poly- and paraphyletic relationships in African green monkeys (Chlorocebus), suggesting contemporary and/or ancient introgressive hybridization among almost all parapatric species of the genus. However, mtDNA analyses alone do not allow us to draw conclusions concerning introgression events. In this study we analyzed two Y chromosomal (Y-chr) markers for 30 African green monkey samples and compared the resulting genetic relationships to those based on published mtDNA data. In line with the results for mtDNA, we found no Y-chr evidence of hypothesized hybridization among Chlorocebus sabaeus and C. tantalus in the northern part of the contact zone in West Africa, and we found two distinct and distantly related Y-chr haplotypes within the range of C. tantalus, suggesting possible cryptic genetic diversity rather than ancient introgressive hybridization in this species. In contrast, Y-chr data revealed monophyletic relationships within Chlorocebus pygerythrus from East Africa, suggesting that mtDNA paraphylies found in this species are most likely to be the result of ancient introgressive hybridization and subsequent cytonuclear extinction of an earlier taxon. Our results accentuate the importance of analyzing sex chromosomal data in addition to mtDNA to obtain more information on the potential outcomes of hybridization with respect to genetic and species diversity. Analysis of more diverse nuclear marker sets is needed to obtain a more complete picture of the African green monkey evolution.International Journal of Primatology 10/2013; 34(5):986-999. DOI:10.1007/s10764-013-9717-5 · 1.99 Impact Factor
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ABSTRACT: Baboons (genus Papio) are an interesting phylogeographical primate model for the evolution of savanna species during the Pleistocene. Earlier studies, based on partial mitochondrial sequence information, revealed seven major haplogroups indicating multiple para- and polyphylies among the six baboon species. The most basal splits among baboon lineages remained unresolved and the credibility intervals for divergence time estimates were rather large. Assuming that genetic variation within the two studied mitochondrial loci so far was insufficient to infer the apparently rapid early radiation of baboons we used complete mitochondrial sequence information of ten specimens, representing all major baboon lineages, to reconstruct a baboon phylogeny and to re-estimate divergence times. Our data confirmed the earlier tree topology including the para- and polyphyletic relationships of most baboon species; divergence time estimates are slightly younger and credibility intervals narrowed substantially, thus making the estimates more precise. However, the most basal relationships could not be resolved and it remains open whether (1) the most southern population of baboons diverged first or (2) a major split occurred between southern and northern clades. Our study shows that complete mitochondrial genome sequences are more effective to reconstruct robust phylogenies and to narrow down estimated divergence time intervals than only short portions of the mitochondrial genome, although there are also limitations in resolving phylogenetic relationships. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.American Journal of Physical Anthropology 01/2013; 150(1). DOI:10.1002/ajpa.22185 · 2.51 Impact Factor
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ABSTRACT: Three fossils, a cranium of Papio, a cercopithecid frontal bone, and a mandible of juvenile Papio, have been recovered from cave deposits in the !Ncumtsa (Koanaka) Hills of western Ngamiland, Botswana. These specimens are significant because well-preserved crania of Papio are extremely rare in the fossil record outside of South Africa and because this is the first report of fossil primate cranial remains from Botswana. Thermoluminescence dating of surrounding cave matrix indicates an age of ≥317 ± 114 ka, within the Middle Pleistocene, although it may be older. Based on univariate and multivariate analyses, the adult !Ncumtsa specimen falls within the range of variation seen in extant forms of Papio, yet is distinct from any living species/subspecies and represents a new taxon, named here as a new subspecies of Papio hamadryas-Papio hamadryas botswanae.American Journal of Physical Anthropology 09/2012; 149(1):1-17. DOI:10.1002/ajpa.22093 · 2.51 Impact Factor