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The increasing awareness that hybridization, and resultant gene flow, plays a major role in animal diversification has led to a growing number of studies that have focused on assessing the morphological consequences of this process. Analyses of mammalian hybrids have identified skeletal effects of hybridization, including a suite of anomalous dental and sutural traits on the skull that are present at high frequencies in hybrid populations. These studies have also detected consistent patterns of morphological shape and size differences between hybrids and parental taxa across a wide variety of organisms. However, more research is required to understand the universality of these traits and shape/size differences. Building on these previous studies, a sample of genetically determined canid hybrids was examined, specifically the eastern coyote (Canis latrans var.), a hybrid between coyotes, wolves, and dogs, to test whether this group exhibits a comparable pattern of anomalous nonmetric characters, and to assess differences in craniomandibular shape and size. First, specimens of C. latrans var., C. latrans, and C. lupus were scored for anomalous traits, including supernumerary and rotated teeth, dental crowding, and sutural anomalies. Geometric morphometric analyses were then conducted on a subset of these individuals to explore craniomandibular size and shape variation, as well as allometry. The results are largely consistent with other studies, indicating that the incidence of dental anomalies, dental crowding, and sutural anomalies is significantly higher in hybrids. However, differences are not significant for supernumerary teeth. The exploration of morphometric variation identifies intermediate morphology in the hybrids, and some indication of greater morphological variability in the mandible. When these results are combined with previous studies, they suggest that skeletal signatures of hybridization are common to different mammalian taxa across multiple generations; however, some traits such as supernumerary teeth may be lost after a few generations.

Complex morphological traits are the product of many genes with transient or lasting developmental effects that interact in anatomical context. Mouse models are a key resource for disentangling such effects, because they offer myriad tools for manipulating the genome in a controlled environment. Unfortunately, phenotypic data are often obtained using laboratory-specific protocols, resulting in self-contained datasets that are difficult to relate to one another for larger scale analyses. To enable meta-analyses of morphological variation, particularly in the craniofacial complex and brain, we created MusMorph, a database of standardized mouse morphology data spanning numerous genotypes and developmental stages, including E10.5, E11.5, E14.5, E15.5, E18.5, and adulthood. To standardize data collection, we implemented an atlas-based phenotyping pipeline that combines techniques from image registration, deep learning, and morphometrics. Alongside stage-specific atlases, we provide aligned micro-computed tomography images, dense anatomical landmarks, and segmentations (if available) for each specimen (N=10,056). Our workflow is open-source to encourage transparency and reproducible data collection. The MusMorph data and scripts are available on FaceBase (www.facebase.org, doi.org/10.25550/3-HXMC) and GitHub (https://github.com/jaydevine/MusMorph).

During the late Pleistocene, isolated lineages of hominins exchanged genes thus influencing genomic variation in humans in both the past and present. However, the dynamics of this genetic exchange and associated phenotypic consequences through time remain poorly understood. Gene exchange across divergent lineages can result in myriad outcomes arising from these dynamics and the environmental conditions under which it occurs. Here we draw from our collective research across various organisms, illustrating some of the ways in which gene exchange can structure genomic/phenotypic diversity within/among species. We present a range of examples relevant to questions about the evolution of hominins. These examples are not meant to be exhaustive, but rather illustrative of the diverse evolutionary causes/consequences of hybridization, highlighting potential drivers of human evolution in the context of hybridization including: influences on adaptive evolution, climate change, developmental systems, sex-differences in behavior, Haldane’s rule and the large X-effect, and transgressive phenotypic variation.

South Africa has an extraordinary record of human evolution spanning from our early hominin ancestors in the Cradle of Humankind World Heritage site, through to more recent evidence for the emergence of modern humans. Human evolution research in South Africa has received international attention for nearly a hundred years and has been vast and broad in terms of research foci, as well as researcher participation. However, the leading researchers in South Africa have been almost entirely men, with women and people of colour under-represented, and black women largely absent. Since its inception in 2016, the Human Evolution Research Institute (HERI) at the University of Cape Town (UCT) has developed a tangible plan to change this: to disrupting, transform and decolonise the long held patriarchal narrative of human evolution in South Africa. Our intervention has a three-tiered design, focusing on the institutional (UCT), the current undergraduate and postgraduate student body, and the public. Using HERI, we are creating more inclusive and diverse spaces for the production and dissemination of high-quality research into human origins, through both physical changes and interactive programmes (e.g. seminars, workshops). We bring young, black women into this space, facilitate cohort-building, and give them knowledge, skills and courage to be the future of scholarship into human evolution in South Africa. We have programmes in place to support and graduate a new cohort of young, black woman PhD students, as well as postdoctoral support that will provide a stepping-stone for these young women to continue in their scientific careers. Field camps are used to demystify the fieldwork experience and encourage interaction between undergraduate and postgraduate women – as well as academics – and help younger women receive the skills they need, as well as the experiences necessary to spark their interest and imagine themselves entering the discipline. Finally, in order to reach beyond the bounds of higher education institutes and out into the public domain, we are developing a new, permanent museum exhibition on human evolution at the Iziko Museum of South Africa, in Cape Town. The exhibition reframes the human origins narrative to centre on the diversity of all people in South Africa, exploring how evolution produced that diversity through a lens of inclusivity and aiming to demystify the topic in an environment that is not alienating but welcoming.

Ancient DNA analyses have shown that interbreeding between hominin taxa occurred multiple times. Although admixture is often reflected in skeletal phenotype, the relationship between the two remains poorly understood, hampering interpretation of the hominin fossil record. Direct study of this relationship is often impossible due to the paucity of hominin fossils and difficulties retrieving ancient genetic material. Here, we use a sample of known ancestry hybrids between two closely related nonhuman primate taxa (Indian and Chinese Macaca mulatta) to investigate the effect of admixture on skeletal morphology. We focus on pelvic shape, which has potential fitness implications in hybrids, as mismatches between maternal pelvic and fetal cranial morphology are often fatal to mother and offspring. As the pelvis is also one of the skeletal regions that differs most between Homo sapiens and Neanderthals, investigating the pelvic consequences of interbreeding could be informative regarding the viability of their hybrids. We find that the effect of admixture in M. mulatta is small and proportional to the relatively small morphological difference between the parent taxa. Sexual dimorphism appears to be the main determinant of pelvic shape in M. mulatta. The lack of difference in pelvic shape between Chinese and Indian M. mulatta is in contrast to that between Neanderthals and H. sapiens, despite a similar split time (in generations) between the hybridizing pairs. Greater phenotypic divergence between hominins may relate to adaptations to disparate environments but may also highlight how the unique degree of cultural buffering in hominins allowed for greater neutral divergence. In contrast to some previous work identifying extreme morphologies in first- and second-generation hybrids, here the relationship between pelvic shape and admixture is linear. This linearity may be because most sampled animals have a multigenerational admixture history or because of relatively high constraints on the pelvis compared with other skeletal regions.

The data and methods presented in this article are supplementing the research article ''Integration of mtDNA pseudogenes into the nuclear genome coincides with speciation of the human genus. A hypothesis'', DOI: 10.1016/j.mito.2016.12.001 (Gunbin et al., 2017) [1]. Mitochondrial DNA is known to get inserted into nuclear DNA to form NUMTs, i.e. nuclear DNA pseudogenes of the mtDNA. We present here the sequences of selected NUMTs, in which time of integration can be determined with sufficient precision. We report their chromosomal positions , their position within the great ape mtDNA phylogeny, and their times of integration into the nuclear genome. The methods used to generate the data and to control their quality are also presented. The dataset is made publicly available to enable critical or extended analyzes. Keywords: NUMT, Human evolution, Mitochondrial DNA, Pseudogene, Speciation, Punctuated evolution

The history of scientific discovery is overwhelmingly told as a narrative of the lives and discoveries of a series of remarkable white men. Christa Kuljian’s real triumph in this book is that she reframes the narrative of palaeoanthropological discovery in South Africa as a tale of flawed men who succeed – through some combination of luck, skill, personality and perseverance – literally and figuratively on the backs of black bodies. That she tells this story with limited cynicism and anger is a testament to the author. This book takes a rich, personal, archivally-intensive and interview-based look at the history of palaeoanthropology that is uncommon in our field, focussing on a region of the world where the global context of racism and the eugenics movement in the 20th century was further compounded by state-sanctioned apartheid. It is a timely tale of racism and misogyny and how they shape scientists, the scientific enterprise, and narratives of human origins and evolution. Although a large portion of this book is historical, it brings the reader right up to the present, and contains themes that remain relevant today, in the age of #BlackLivesMatter, #MeToo, and other pertinent movements, and affect our field more generally. In this review, I will first provide a very brief summary of the book. I will then highlight what I believe are the book’s most salient themes that are relevant to biological anthropology today: racism in science, intersectionality, and the invalid (but still prevalent) idea that scientists and their work can be separated. Finally, I will consider current practice in palaeoanthropology, as well as various reviews of the book, in order to reflect on these issues.

In their seminal works on postcolonialism, Edward Saïd (in Orientalism) and V.Y. Mudimbe (in The Idea of Africa) proposed that Asia and Africa, respectively, were constructs created around the notion of their otherness. Both regions were viewed as infantile, primitive, and homogenous entities that fell outside the domain of civilized (i.e. Western) humanity. These constructs shaped scientific perceptions of both continents over the course of several centuries and have continued to be operative over the last 100 years following the discovery of fossil human ancestors, particularly within the narratives of recent human origins. Here we reflect on these narratives, both in the early days of the discoveries and more recently, in the context of the othered identities of the continents more broadly. We argue that a colonialist socio-political framework has shaped the science of human origins since its inception, and that this has negatively affected the quality of this endeavour. Existing phylogenies cannot be divorced from those ideologies—even today. Indeed, while the details of human origins (e.g. when, where, who) have changed radically over time, the narrative that emerged always left one group in control, and marginalised non-Western lands and their peoples, leaving the ordering of superior and inferior more or less unchanged through the history of the discipline. More informed models of human evolution cannot be constructed until the community of voices constructing them is reworked to be more inclusive of many worldviews.

Recent genomic research has shown that hybridization between substantially diverged lineages is the rule, not the exception, in human evolution. However, the importance of hybridization in shaping the genotype and phenotype of Homo sapiens remains debated. Here we argue that current evidence for hybridization in human evolution suggests not only that it was important, but that it was an essential creative force in the emergence of our variable, adaptable species. We then extend this argument to a reappraisal of the archaeological record, proposing that the exchange of cultural information between divergent groups may have facilitated the emergence of cultural innovation. We discuss the implications of this Divergence and Hybridization Model for considering the taxonomy of our lineage.

The question: human evolution- gradual process or a rapid discontinuous change? Whether human origin was a gradual process or a result of rapid change has been a focus of intense debate. Of particular interest is the climate change ~2.9-2.5 Ma, thought to have precipitated the separation of the genus Homo (~2.8Ma). The debate mostly concerned continuity/punctuality of the fossil record, but of course the rate of the underlying genetic change is of ultimate interest/importance. Did hominid lineage experience an increased mutation rate when a large number of hominins emerged and eventually gave rise to the split between Australopitecus/Paranthropus and Homo? The obstacle: vague timing of conventional mutations. The difficulty in answering the above question lies in the way past mutations are timed. Conventional point mutations are assigned to specific branches of the DNA-derived phylogenetic trees. The essence of the problem is that mutations can be located within branch segments from branching point to branching point, but the exact position within the segment is principally unknown. Because the hominid DNA-derived phylogenetic tree is rather sparsely populated with branches, the precision of mutation timing is low, e.g., human-specific mutations can be positioned within ~6 My from separation from chimpanzee. The solution: NUMTs – mutations with an internal clock. NUMTs are insertions of mtDNA sequences into the nuclear genome. Unlike point mutation, each NUMTs actually represents a branch on the mtDNA phylogenic tree and thus its time of insertion can be determined as precise as their branching point can be positioned on the tree. In a sense, NUMTs are “mutations with an internal clock”, which is synchronized with the well-established mtDNA mutation evolution clock. By determining the NUMTs’ insertion time points, one can ask whether whether NUMTs were inserted at a constant rate over time or at increased rate during critical periods of evolution, according with the “punctuated evolution” model. Results: Hundreds of pseudogenes have been inserted into the human genome over the last ~60 My of which we considered the last 6 My. Various quality filters resulted in the selection of 18 NUMTs most suitable for phylogenetic analysis. Insertion times of these 18 NUMTs cluster around 2.8Ma. While timing of insertion of NUMTs is imprecise, the observation such a cluster is highly statistically significant. Discussion: It is tempting to hypothesize that accelerated insertion of NUMTs is somehow linked to the speciation process. NUMTs could be either "riders i.e., the rate of insertion could be increased by the overall higher genome flexibility during the speciation period, or "drivers", i.e. they are fixed in the population at increased rate during speciation due to increased selective pressures. If correct, the hypothesis of accelerated pseudogenization would support the idea that evolution of our genus might have been discontinuous.

Introduction: Increasingly, the emergence and evolution of our species is being tied to genetic exchange between divergent lineages within ~1Ma (e.g., Neanderthals, Denisovans). However, little is known about genetic exchange during earlier (pre-1Ma) human evolution and between more divergent lineages. Results: We present evidence of hybridization within human lineage, show that it likely happened between highly divergent (~4.5My) lineages, more than once. We use analysis of nuclear pseudogenes of mtDNA (“NUMTs”). NUMTs are considered “mtDNA fossils”, as they preserve sequences of ancient mtDNA because mutational rate in the nucleus is much lower than in mtDNA. We demonstrate that a NUMT on human chromosome 5, which is shared by chimpanzee and gorilla, had descended from a mitochondrial genome that had been divergent from our ancestor’s mtDNA by ~4.5% at the time of pseudogene insertion. This implies that this pseudogene should have been inserted in a hominid that at that time had been diverged by about 4.5My of evolution from the hominid that at that time carried our mtDNA lineage. In order for this pseudogene and our mtDNA to end up in the same body, these two hominids should have mated with each other. The large divergence implies a distant interspecies (or even inter-generic) hybridization. Additionally, analysis of two other NUMTs (on Chr11 and Chr7) suggests that hybridization events occurred repeatedly. To exclude the large ancestral population size effect we show that mtDNA divergence in extant ape populations does not depend on population size. Discussion: It is thought that within mammals, it takes ~2-4My to establish reproductive isolation. However, fertile inter-generic hybrids have been documented among several primates, separated by ca. 4My. Very recently, hybridization between Colobine genera separated by ~5 My was reported to involve a NUMT scenario similar to what we had proposed human ancestors. Interestingly, phylogenic analysis consistently places the chr5 NUMT insertion around the time of the Homo/Pan split. Intriguingly, certain hominin fossils of that epoch have been interpreted alternately as more human-like or more ape-like. Such morphological mosaicisity could potentially be explained by hybridization. Fixation of NUMTs in question within population should have been rather efficient, since these pseudogenes appear to have been fixed in more than one population. Thus their spread across populations might have been driven by selection. Indeed, NUMTs on chr5 and chr11 are located in 3’ regions of functional genes. Most intriguingly, Ps11 is located 3’ to the RNF141/ZNF230 gene, essential for spermatogenesis. NUMT might have served as an expression modifier for RNF141, resulting in reproductive advantage. Indeed, RNF141 demonstrates selectively driven expression shift in testis of the ancestor of hominines.

Recent fossil finds have highlighted extensive morphological diversity within our genus, Homo, and the co-existence of a number of species. However, little is known about the evolutionary processes responsible for producing this diversity. Understanding the action of these processes can provide insight into how and why our lineage evolved and diversified. Here, we examine cranial and mandibular variation and diversification from the earliest emergence of our genus at 2.8 Ma until the Late Pleistocene (0.126-0.0117 Ma), using statistical tests developed from quantitative genetics theory to evaluate whether stochastic (genetic drift) versus non-stochastic (selection) processes were responsible for the observed variation. Results show that random processes can account for species diversification for most traits, including neurocranial diversification, and across all time periods. Where selection was found to shape diversification, we show that: 1) adaptation was important in the earliest migration of Homo out of Africa; 2) selection played a role in shaping mandibular and maxillary diversity among Homo groups, possibly due to dietary differences; and 3) Homo rudolfensis is adaptively different from other early Homo taxa, including the earliest known Homo specimen. These results show that genetic drift, and likely small population sizes, were important factors shaping the evolution of Homo and many of its novel traits, but that selection played an essential role in driving adaptation to new contexts.

The hypothesis that the evolution of humans involved hybridization between diverged species has been actively debated in recent years. We present novel evidence in support of this hypothesis: the analysis of nuclear pseudogenes of mtDNA (“NUMTs”). NUMTs are considered “mtDNA fossils”, as they preserve sequences of ancient mtDNA and thus carry unique information about ancestral populations. Our comparison of a NUMT sequence shared by humans, chimpanzees, and gorillas with their mtDNAs implies that, around the time of divergence between humans and chimpanzees, our evolutionary history involved the interbreeding of individuals whose mtDNA had diverged as much as ~4.5 Myr prior. This large divergence suggests a distant interspecies hybridization. Additionally, analysis of two other NUMTs suggests that such events occurred repeatedly. Our findings suggest a complex pattern of speciation in primate human ancestors and provide a potential explanation for the mosaic nature of fossil morphology found at the emergence of the hominin lineage.

The species Homo naledi was recently named from specimens recovered from the Dinaledi Chamber of the Rising Star cave system in South Africa. This large skeletal sample lacks associated faunal material and currently does not have a known chronological context. In this paper, we present comprehensive descriptions and metric comparisons of the recovered cranial and mandibular material. We describe 41 elements attributed to Dinaledi Hominin (DH1–DH5) individuals and paratype U.W. 101-377, and 32 additional cranial fragments. The H. naledi material was compared to Plio- Pleistocene fossil hominins using qualitative and quantitative analyses including over 100 linear measurements and ratios. We find that the Dinaledi cranial sample represents an anatomically homogeneous population that expands the range of morphological variation attributable to the genus Homo. Despite a relatively small cranial capacity that is within the range of australopiths and a few specimens of early Homo, H. naledi shares cranial characters with species across the genus Homo, including Homo habilis, Homo rudolfensis, Homo erectus, and Middle Pleistocene Homo. These include aspects of cranial form, facial morphology, and mandibular anatomy. However, the skull of H. naledi is readily distinguishable from existing species of Homo in both qualitative and quantitative assessments. Since H. naledi is currently undated, we discuss the evolutionary implications of its cranial morphology in a range of chronological frameworks. Finally, we designate a sixth Dinaledi Hominin (DH6) individual based on a juvenile mandible.

The present report follows up on the findings of previous research, including recent bioarchaeological study of well-dated Khoesan skeletal remains, that posits long term biological continuity among the indigenous peoples of South Africa after the Pleistocene. The Arizona State University Dental Anthropology System was used to record key crown, root, and intraoral osseous nonmetric traits in six early-through-late Holocene samples from the Cape coasts. Based on these data, phenetic affinities and an identification of traits most important in driving intersample variation were determined using principal components analysis and the mean measure of divergence distance statistic. To expand biological affinity comparisons into more recent times, and thus preliminarily assess the dental impact of disproportionate non-Khoesan gene flow into local peoples, dental data from historic Khoekhoe and San were also included. Results from the prehistoric comparisons are supportive of population continuity, though a sample from Matjes River Rockshelter exhibits slight phenetic distance from other early samples. This and some insignificant regional divergence among these coastal samples may be related to environmental and cultural factors that drove low-level reproductive isolation. Finally, a close affinity of historic San to all samples, and a significant difference of Khoekhoe from most early samples is reflective of documented population history following immigration of Bantu-speakers and, later, Europeans into South Africa. Am J Phys Anthropol 155:33–44, 2014. © 2014 Wiley Periodicals, Inc.

Hybridization occurs in a number of mammalian lineages, including among primate taxa. Analyses of ancient genomes have shown that hybridization between our lineage and other archaic hominins in Eurasia occurred numerous times in the past. However, we still have limited empirical data on what a hybrid skeleton looks like, or how to spot patterns of hybridization among fossils for which there are no genetic data. Here we use experimental mouse models to supplement previous studies of primates. We characterize size and shape variation in the cranium and mandible of three wild-derived inbred mouse strains and their first generation (F1) hybrids. The three parent taxa in our analysis represent lineages that diverged over approximately the same period as the human/Neanderthal/Denisovan lineages and their hybrids are variably successful in the wild. Comparisons of body size, as quantified by long bone measurements, are also presented to determine whether the identified phenotypic effects of hybridization are localized to the cranium or represent overall body size changes. The results indicate that hybrid cranial and mandibular sizes, as well as limb length, exceed that of the parent taxa in all cases. All three F1 hybrid crosses display similar patterns of size and form variation. These results are generally consistent with earlier studies on primates and other mammals, suggesting that the effects of hybridization may be similar across very different scenarios of hybridization, including different levels of hybrid fitness. This paper serves to supplement previous studies aimed at identifying F1 hybrids in the fossil record and to introduce further research that will explore hybrid morphologies using mice as a proxy for better understanding hybridization in the hominin fossil record.

Fragments of mitochondrial DNA are known to get inserted into nuclear DNA to form NUMTs, i.e. nuclear pseudogenes of the mtDNA. The insertion of a NUMT is a rare event. Hundreds of pseudogenes have been cataloged in the human genome. NUMTs are, in essence, a special type of mutation with their own internal timer, which is synchronized with an established molecular clock, the mtDNA. Thus insertion of NUMTs can be timed with respect to evolution milestones such as the emergence of new species. We asked whether NUMTs were inserted uniformly over time or preferentially during certain periods of evolution, as implied by the “punctuated evolution” model. To our surprise, the NUMT insertion times do appear nonrandom with at least one cluster positioned at around 2.8 million years ago (Ma). Interestingly, 2.8 Ma closely corresponds to the time of emergence of the genus Homo, and to a well-documented period of major climate change ca. 2.9–2.5 Ma. It is tempting to hypothesize that the insertion of NUMTs is related to the speciation process. NUMTs could be either “riders”, i.e., their insertion could be facilitated by the overall higher genome rearrangement activity during speciation, or “drivers”, i.e. they may more readily get fixed in the population due to positive selection associated with speciation. If correct, the hypothesis would support the idea that evolution of our genus may have happened in a rapid, punctuated manner.

Langebaanweg (LBW) is a Mio-Pliocene fossil site located on the west coast of South Africa, approximately 120 km north of Cape Town. The combination of terrestrial, riverine and marine fauna suggests that it was an estuary at the time of deposition. Early studies of the fossil phocid seal, Homiphoca capensis, from LBW suggested that it is morphologically intermediate between the monk and Antarctic phocid seal, with close affinities to the crabeater seal in particular. Here we re-examine the fossil phocid seal collection, using both descriptive and morphometric approaches, and reveal substantial variation in cranial and postcranial skeletons. The variation present in the postcranium suggests that two morphotypes are present in the sample. The morphometric analyses of the crania confirm that the LBW seals are similar in many respects, including overall size, to extant crabeater seals. However, the LBW seals appear to be more variable than any individual extant seal taxon, while examination of fine-...

SK 847 and StW 53 have often been cited as evidence for early Homo in South Africa. To examine whether midfacial morphology is in agreement with these attributions, we analyze Euclidean distances calculated from 3-D coordinates on the maxillae of SK 847 and StW 53, as well as Australopithecus africanus (Sts 5, Sts 71), Paranthropus robustus (SK 46, SK 48, SK 52, SK 83), early Homo (KNM-ER 1813, KNM-ER 1805, KNM-ER 3733, KNM-WT 15000), P. boisei (KNM-ER 406, KNM-WT 17000, KNM-WT 17400), Gorilla gorilla (n = 116), Homo sapiens (n = 342), Pan paniscus (n = 21) and P. troglodytes (n = 65). Multivariate analyses separate extant hominoids suggesting we have captured taxonomic affinity. With the exception of SK 847 and SK 52, South African fossils tend to cluster together. P. robustus differs substantially from East African robust megadonts. SK 847 and StW 53 resemble the East African Homo specimens that are the most australopith-like, such as KNM-WT 15000 and KNM-ER 1813. The resemblance between StW 53 and Homo is driven partly by similarities in maxillary size. When distances are scaled, StW 53 aligns with A. africanus, while SK 847 clusters primarily with early Homo.

For many years, the likelihood that hybridization occurred in human evolution has been debated. Tattersall and Schwartz pointed out one of the core problems with resolving this debate, namely “that nobody has any idea what a Neanderthal/modern human hybrid might look like in theory, and few have dared to suggest in practice that any particular known fossil represents such a hybrid.”1:7117 Moreover, while molecular data is proving increasingly useful for characterising hybrid zones, the utility of the phenotype for this purpose is not clear.2 Here I address these issues, discussing both theoretical and empirically-derived expectations for what hybrid morphology looks like, with an emphasis on the skeleton of hybrid primates, and consideration of the hominin fossil record.

Molecular studies have demonstrated a deep lineage split between the two gorilla species, as well as divisions within these taxa; estimates place this divergence in the mid-Pleistocene, with gene flow continuing until approximately 80,000 years ago. Here, we present analyses of skeletal data indicating the presence of substantial recent gene flow among gorillas at all taxonomic levels: between populations, subspecies, and species. Complementary analyses of DNA sequence variation suggest that low-level migration occurred primarily in a westerly-to-easterly direction. In western gorillas, the locations of hybrid phenotypes map closely to expectations based on population refugia and riverine barrier hypotheses, supporting the presence of significant vicariance-driven structuring and occasional admixture within this taxon. In eastern lowland gorillas, the high frequency of hybrid phenotypes is surprising, suggesting that this region represents a zone of introgression between eastern gorillas and migrants from the west, and underscoring the conservation priority of this critically endangered group. These results highlight the complex nature of evolutionary divergence in this genus, indicate that historical gene flow has played a major role in structuring gorilla diversity, and demonstrate that our understanding of the evolutionary processes responsible for shaping biodiversity can benefit immensely from consideration of morphological and molecular data in conjunction.

Various methodological approaches have been used for reconstructing fossil hominin remains in order to increase sample sizes and to better understand morphological variation. Among these, morphometric quantitative techniques for reconstruction are increasingly common. Here we compare the accuracy of three approaches--mean substitution, thin plate splines, and multiple linear regression--for estimating missing landmarks of damaged fossil specimens. Comparisons are made varying the number of missing landmarks, sample sizes, and the reference species of the population used to perform the estimation. The testing is performed on landmark data from individuals of Homo sapiens, Pan troglodytes and Gorilla gorilla, and nine hominin fossil specimens. Results suggest that when a small, same-species fossil reference sample is available to guide reconstructions, thin plate spline approaches perform best. However, if no such sample is available (or if the species of the damaged individual is uncertain), estimates of missing morphology based on a single individual (or even a small sample) of close taxonomic affinity are less accurate than those based on a large sample of individuals drawn from more distantly related extant populations using a technique (such as a regression method) able to leverage the information (e.g., variation/covariation patterning) contained in this large sample. Thin plate splines also show an unexpectedly large amount of error in estimating landmarks, especially over large areas. Recommendations are made for estimating missing landmarks under various scenarios.

The fossil record of primate and human evolution cannot provide accurate estimates of within species variation and integration. This means that we cannot directly observe how patterns of integration have evolved over time in this lineage. And yet, our interpretations of fossil diversity are awash with assumptions about variation patterning in precisely these fossil taxa. Most commonly, researchers rely on extant models of variation for interpreting past diversity, by assuming equality of variation (and occasionally covariation) among extant and fossil populations. Yet one of the things we know from studies of integration in primates is that patterns of morphological covariation can differ among even closely related taxa, indicating that they have diverged over evolutionary time, either in response to selection or as the result of neutral evolution. At the same time, overall patterns of integration remain remarkably similar, meaning that in many respects they are highly conserved evolutionarily. Taken together, these seemingly contradictory observations offer an important conceptual framework for interpreting patterns that we observe in the fossil past. This framework dictates that while we can use patterns of covariation in extant taxa as proxies for extinct diversity, and indeed their conserved nature makes them superior to approaches that rely on variation alone, we also need to account for the fact that such patterns change over time, and incorporate that into our models. Here I provide examples using covariation patterns estimated from modern humans and African great apes to demonstrate the extent to which divergence in covariance structure might affect our interpretations of hominin diversity.

We assess craniometric variation in 153 individually dated human crania from South Africa with the aim of investigating genetic continuity/discontinuity during the Holocene. Evidence from the archaeological record is used to pinpoint likely episodes of genetic discontinuity. Craniometric data are then used to assess the likelihood of genetic change having occurred. Two periods of possible genetic discontinuity are identified: i) c. 4,000 BP, when an increase in overall population size, shifts in site organization and diet, and reduced mobility, were accompanied by reductions in stature; ii) c. 2,000 BP, when the herding of domesticates and the use of pottery vessels were introduced into the region. Results indicate that there was a decrease in cranial size and concomitant size-related changes in craniofacial shape between c.4,000 BP and 3,000 BP. This was followed almost immediately by a recovery in craniofacial size and a return to pre-4,000 BP craniofacial shape at c. 3,000 BP. This recovery continued gradually, extending into the herder period without any major shifts in morphology at 2,000 BP. It is suggested that the fluctuations in craniofacial size/shape were related to changes in environmental factors. Results obtained are consistent with long term continuity in South African Later Stone Age populations during the Holocene.

Quantitative, evolutionary models that incorporate within- and between-species variation are critical for interpreting the fossil record of human diversity, and for making taxonomic distinctions. However, small sample sizes, sexual dimorphism, temporal trends, geographic variation, and the limited number of relevant extant models have always made the consideration of variation difficult for paleoanthropologists. Here we provide a brief overview of current early hominin diversity. We then argue that for many species our limited understanding of within species variation hampers our ability to make taxonomic decisions with any level of statistical certainty. Perhaps more significantly, the underlying causes of between-species variation among early hominins are poorly studied. There have been few attempts to correlate aspects of the phenotype with meaningful evidence for niche differentiation, to demonstrate the selective advantage of traits, or to provide other evidence for macroevolutionary divergence. Moreover, current depictions of vast pattern (but not size) diversity are inconsistent with expectations derived from most other extant primate clades that have adaptively radiated. If indeed the early hominin record is highly speciose, the reasons for this remain unclear.

© Berger et al. Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.

Acknowledgements We wish to express our gratitude to the National Geographic Society and the National Research Foundation of South Africa for funding the discovery, recovery, and analysis of the H. naledi material. The study reported here was also made possible by grants from the Social Sciences and Humanities Research Council of Canada, the Canada Foundation for Innovation, the British Columbia Knowledge Development Fund, the Canada Research Chairs Program, Simon Fraser University, the DST/NRF Centre of Excellence in Palaeosciences (COE-Pal), as well as by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada, a Young Scientist Development Grant from the Paleontological Scientific Trust (PAST), a Baldwin Fellowship from the L.S.B. Leakey Foundation, and a Seed Grant and a Cornerstone Faculty Fellowship from the Texas AM the Jacobs family for granting access; Wilma Lawrence, Bonita De Klerk, Merrill Van der Walt, and Justin Mukanku for their assistance during all phases of the project; Lucas Delezene for valuable discussion on the dental characters of H. naledi. We would also like to thank Peter Schmid for the preparation of the Dinaledi fossil material; Yoel Rak for explaining in detail some of the characters used in previous studies; William Kimbel for drawing our attention to the possibility that there might be a problem with Dembo et al.’s (2015) codes for the two characters related to the articular eminence; Will Stein for helpful discussion about the Bayesian analyses; Mike Lee for his comments on this manuscript; John Hawks for his support in organizing the Rising Star workshop; and the associate editor and three anonymous reviewers for their valuable comments. We are grateful to S. Potze and the Ditsong Museum, B. Billings and the School of Anatomical Sciences at the University of the Witwatersrand, and B. Zipfel and the Evolutionary Studies Institute at the University of the Witwatersrand for providing access to the specimens in their care; the University of the Witwatersrand, the Evolutionary Studies Institute, and the South African National Centre of Excellence in PalaeoSciences for hosting a number of the authors while studying the material; and the Western Canada Research Grid for providing access to the high-performance computing facilities for the Bayesian analyses. Last but definitely not least, we thank the head of the Rising Star project, Lee Berger, for his leadership and support, and for encouraging us to pursue the study reported here.

The discovery of Homo naledi has expanded the range of phenotypic variation in Homo , leading to new questions surrounding the mosaic nature of morphological evolution. Though currently undated, its unique morphological pattern and possible phylogenetic relationships to other hominin taxa suggest a complex evolutionary scenario. Here, we perform geometric morphometric analyses on H. naledi cranial and mandibular remains to investigate its morphological relationship with species of Homo and Australopithecus . We use Generalized Procrustes analysis to place H. naledi within the pattern of known hominin skull diversity, distributions of Procrustes distances among individuals to compare H. naledi and Homo erectus , and neighbor joining trees to investigate the potential phenetic relationships between groups. Our goal is to address a set of hypotheses relating to the uniqueness of H. naledi , its affinity with H. erectus , and the age of the fossils based on skull morphology. Our results indicate that, cranially, H. naledi aligns with members of the genus Homo , with closest affiliations to H. erectus . The mandibular results are less clear; H. naledi closely associates with a number of taxa, including some australopiths. However, results also show that although H. naledi shares similarities with H. erectus , some distances from this taxon – especially small-brained members of this taxon – are extreme. The neighbor joining trees place H. naledi firmly within Homo . The trees based on cranial morphology again indicate a close relationship between H. naledi and H. erectus , whereas the mandibular tree places H. naledi closer to basal Homo , suggesting a deeper antiquity. Altogether, these results emphasize the unique combination of features ( H. erectus -like cranium, less derived mandible) defining H. naledi . Our results also highlight the variability within Homo , calling for a greater focus on the cause of this variability, and emphasizing the importance of using the total morphological package for species diagnoses.

Plio-Pleistocene environmental change influenced the evolutionary history of many animal lineages in Africa, highlighting key roles for both climate and tectonics in the evolution of Africa’s faunal diversity. Here, we explore diversification in the southern African chacma baboon Papio ursinus sensu lato and reveal a dominant role for increasingly arid landscapes during past glacial cycles in shaping contemporary genetic structure. Recent work on baboons ( Papio spp.) supports complex lineage structuring with a dominant pulse of diversification occurring 1-2Ma, and yet the link to palaeoenvironmental change remains largely untested. Phylogeographic reconstruction based on mitochondrial DNA sequence data supports a scenario where chacma baboon populations were likely restricted to refugia during periods of regional cooling and drying through the Late Pleistocene. The two lineages of chacma baboon, ursinus and griseipes , are strongly geographically structured, and demographic reconstruction together with spatial analysis of genetic variation point to possible climate-driven isolating events where baboons may have retreated to more optimum conditions during cooler, drier periods. Our analysis highlights a period of continuous population growth beginning in the Middle to Late Pleistocene in both the ursinus and the PG2 griseipes lineages. All three clades identified in the study then enter a state of declining population size (Ne f ) through to the Holocene; this is particularly marked in the last 20,000 years, most likely coincident with the Last Glacial Maximum. The pattern recovered here conforms to expectations based on the dynamic regional climate trends in southern Africa through the Pleistocene and provides further support for complex patterns of diversification in the region’s biodiversity.

By investigating similarity in cranial covariation patterns, it is possible to locate underlying functional and developmental causes for the patterning, and to make inferences about the evolutionary forces that have acted to produce the patterns. Furthermore, establishing where these covariation patterns may diverge in ontogeny can offer insight into when selection may have acted on development. Here, covariation patterns are compared among adult and non-adult members of the African ape/human clade, in order to address three questions. First, are integration patterns constant among adult African apes and humans? Second, are they are constant in non-adults – i.e. throughout ontogeny? Third, if they are not constant, when do they diverge? Measurements are obtained from 677 crania of adult and non-adult African apes and humans. In order to address the first two questions, correlation matrices and theoretical integration matrices are compared using matrix correlation methods. The third question is evaluated by comparing correlation and variance/covariance patterns, using matrix correlation and random skewers methods, respectively, between adjacent age categories within each species, and between equivalent age categories among the four species. Results show that the hominoids share a similar pattern of ontogenetic integration, suggesting that common developmental/functional integrative processes may play an important role in keeping covariance structure stable across this lineage. However, there are some important differences in the magnitude of integration and in phenotypic covariance structure among the species, which may provide some insight into how selection acted to differentiate humans from the great apes.

Recent paleoanthropological discoveries reveal a diverse, potentially speciose human fossil record. Such extensive morphological diversity results from the action of divergent evolutionary forces on an evolving lineage. Here, we apply quantitative evolutionary theory to test whether random evolutionary processes alone can explain the morphological diversity seen among fossil australopith and early Homo crania from the Plio–Pleistocene. We show that although selection may have played an important role in diversifying hominin facial morphology in the late Pliocene, this is not the case during the early evolution of the genus Homo , where genetic drift was probably the primary force responsible for facial diversification.

Living species are often used as analogues for fossil ones. When this is done, the implicit assumption is made that hominids and living hominoids vary in the same way. This paper addresses the validity of this assumption by comparing patterns of facial variation among humans and African apes. In particular, it addresses three major questions that underlie approaches to reconstructing hominid relationships. First, is phenotypic variation similar between closely related species? Second, if it is dissimilar, why? Third, is it feasible to use analogue species for modeling purposes? Measurements are obtained from 542 crania of adult apes and humans. Care is taken to choose homologous data, and account for differences in population size and structure. Variance/covariance and correlation matrices among the species are compared using common principal component (CPC) analysis, random skewers methods and matrix correlations. Morphological distances ( D 2 ) are calculated between population means, and between randomized pairs of individuals within each population, to evaluate intraspecific variation. Morphological distances are also calculated between randomized pairs of individuals using the variation patterns of analogue populations, in order to evaluate the efficacy of such substitutions. Results show that while the hominoids share a similar pattern of facial variation overall, the patterns do diverge. This difference generally corresponds to the phylogenetic relationships among these species, suggesting that patterns of variation may have diverged through time in the large bodied hominoids. Because interpretation of relationships in the fossil record is confounded by a lack of understanding of how variation changes through time, exploration of such patterns of divergence can provide important clues to understanding human evolution. Additionally, neglecting to account for this divergence when using living analogues as variation “yardsticks” can give rise to interpretations of the fossil record that are more speciose than is warranted.

Hybridization is increasingly proving to be an important force shaping human evolution. Comparisons of both ancient and modern genomes have provided support for a complex evolutionary scenario over the past million years, with evidence for multiple incidents of gene exchange. However, to date, genetic evidence is still limited in its ability to pinpoint the precise time and place of ancient admixture. For that we must rely on evidence of admixture from the skeleton. The research presented here builds on previous work on the crania of baboon hybrids, focusing on the nasal cavity of olive baboons, yellow baboons, and first generation (F1) hybrids. The nasal cavity is a particularly important anatomical region for study, given the clear differentiation of this feature in Neanderthals relative to their contemporaries, and therefore it is a feature that will likely differ in a distinctive manner in hybrids of these taxa. Metric data consist of 45 linear, area, and volume measurements taken from CT scans of known-pedigree baboon crania. Results indicate that there is clear evidence for differences among the nasal cavities of the parental taxa and their F1 hybrids, including a greater degree of sexual dimorphism in the hybrids. There is also some evidence for transgressive phenotypes in individual F1 animals. The greatest amount of shape variation occurs in the anterior bony cavity, the choana, and the mid-nasopharynx. Extrapolating our results to the fossil record, we would expect F1 hybrid fossils to have larger nasal cavities, on average, than either parental taxon, with overall nasal cavity shape showing the most profound changes in regions that are distinct between the parental taxa (e.g., anterior nasal cavity). We also expect size and shape differences to be more pronounced in male F1 hybrids than in females. Because of pronounced anterior nasal cavity differences between Neanderthals and their contemporaries, we suggest that this model might be effective for examining the fossil record of late Pleistocene contact.

a Paleoanthropology, Senckenberg Center for Human Evolution and Paleoenvironment, Eberhard Karls Universit€ at Tubingen, Rumelinstrasse 23, Tubingen 72070, Germany b Department of Anthropology, Stony Brook University, Stony Brook, 11794-4364 New York, USA c Department of Anatomical Sciences, Stony Brook University, Stony Brook, 11794-4364 New York, USA d Department of Cultural Heritage, University of Bologna, Via degli Ariani 1, 48121 Ravenna, Italy e Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany f Department of Archaeology, University of Cape Town, Rondebosch 7701, South Africa g Institute for Archaeology, History, Culture and Religious Studies, University of Bergen, Oysteinsgate 3, N-5007 Bergen, Norway h Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa

Hybridization may have played a substantial role in shaping the diversity of our evolving lineage. Although recent genomic evidence has shown that hybridization occurred between anatomically modern humans (AMHS) and Neanderthals, it remains difficult to pin down precisely where and when this gene flow took place. Investigations of the hybrid phenotype in primates and other mammals are providing models for identifying signatures of hybridization in the fossil record. However, our understanding of intra- and inter-taxon variation in hybrids is still limited. Moreover, there is little evidence from these studies that is pertinent to the question of how long hybrid skeletal traits persist in descendants, and therefore it is not clear whether observed hybrid phenotypes are evidence of recent (e.g., F1) or much earlier hybridization events. Here, we present an analysis updating a previous study of cranial variation in pedigreed olive and yellow baboons and their hybrids. Results suggest that traits previously associated with hybrids in baboons and other mammalian species are also present in this expanded data set; many of these traits are highly heritable, confirming a genetic basis for their variation in this mixed population. While F1 animals – and especially F1 males – still have the highest number of dental anomalies, these and other atypical traits persist into later hybrid generations (such as F2 and B1). Moreover, non-F1 recombinants also show extremely rare trait variations, including reduced canines and rotated teeth. However, these results must be considered in light of the possibility that some founding individuals may have themselves been unrecognized hybrids. Despite this, the data are compelling, and indicate once again that further controlled research remains to be done on primates and other mammals in order to better understand variation in the hybrid phenotype.

Evolutionary theory and observation predict wider phenotypic variation in hybrids than parental species. Emergent phenotypic novelty in hybrids may in turn drive new adaptations or speciation by breaking parental phenotypic constraints. Primate hybridization is often documented through genetic evidence, but knowledge about the primate hybrid phenotype remains limited due to a small number of available studies on hybrid primate morphology. Here, we examine pelage and morphometric variation in two Brazilian marmoset species (Callithrix penicillata and C. geoffroyi) and their hybrids. Hybrids were sampled in an anthropogenic hybrid zone in the municipality of Vicosa, Minas Gerais state, Brazil. We analyzed hybrid facial and body pelage color variation, and compared 13 morphometric measures between hybrids and parental species. Five different hybrid facial morphotypes were observed, varying from intermediate to parental-like. Hybrid facial morphotypes were biased towards C. penicillata, suggesting that the pelage of this species may be dominant to that of C. geoffroyi in this context, and indicating that mate preference, and therefore gene flow/introgression, may be biased towards C. penicillata within the hybrid zone. Hybrid morphometric features were on average intermediate to parental species traits, but transgressive hybrids were also observed, suggesting that morphometric variation for the studied traits is consistent with Rieseberg’s complementary allele model. Finally, we observed a decoupling of facial patterning and size/shape in hybrids, relative to parent phenotypes, suggesting that an important factor driving phenotypic novelty within the Vicosa marmoset hybrid zone might be the loosening of evolutionary constraints on phenotypic trait integration.

The present report follows up on the findings of previous research, including recent bioarchaeological study of well-dated Khoesan skeletal remains, that posits long term biological continuity among the indigenous peoples of South Africa after the Pleistocene. The Arizona State University Dental Anthropology System was used to record key crown, root, and intraoral osseous nonmetric traits in six early-through-late Holocene samples from the Cape coasts. Based on these data, phenetic affinities and an identification of traits most important in driving intersample variation were determined using principal components analysis and the mean measure of divergence distance statistic. To expand biological affinity comparisons into more recent times, and thus preliminarily assess the dental impact of disproportionate non-Khoesan gene flow into local peoples, dental data from historic Khoekhoe and San were also included. Results from the prehistoric comparisons are supportive of population continuity, though a sample from Matjes River Rockshelter exhibits slight phenetic distance from other early samples. This and some insignificant regional divergence among these coastal samples may be related to environmental and cultural factors that drove low-level reproductive isolation. Finally, a close affinity of historic San to all samples, and a significant difference of Khoekhoe from most early samples is reflective of documented population history following immigration of Bantu-speakers and, later, Europeans into South Africa.

Constancy of variation/covariation structure among populations is frequently assumed in order to measure the differential selective forces which have caused population differentiation through evolutionary time. Following Steppan ([1997] Evolution 51:571-594), this assumption is examined among closely related tamarin species (genus Saguinus), using two distinct approaches applied to the task of evaluating similarity in patterns of morphological variation: common principal component analysis and matrix correlations. While the results of these analyses may appear contradictory, closer examination reveals them as complementary, highlighting the wisdom of combined methodologies. Overall, the results reveal a close relationship among the morphologically based variance structures of the tamarin species a relationship whose pattern is consistent with the pattern of phylogenetic relatedness as found via a molecular genetic study. More specifically, both methodological approaches provide some support for divergence of S. geoffroyi and S. oedipus (with regards to their patterns of morphological variation) from other tamarin species. This suggests that variance/covariance structure may have diverged through evolutionary time in the tamarin lineage, placing assumptions of constancy in doubt.

Since the announcement of the species Australopithecus sediba , questions have been raised over whether the Malapa fossils represent a valid taxon or whether inadequate allowance was made for intraspecific variation, in particular with reference to the temporally and geographically proximate species Au . africanus . The morphology of mandibular remains of Au. sediba , including newly recovered material discussed here, shows that it is not merely a late-surviving morph of Au. africanus . Rather—as is seen elsewhere in the cranium, dentition, and postcranial skeleton—these mandibular remains share similarities with other australopiths but can be differentiated from the hypodigm of Au. africanus in both size and shape as well as in their ontogenetic growth trajectory.

The genus Connochaetes, Lichtenstein, 1814, contains two extant species, the blue wildebeest (C. taurinus, Burchell, 1823) and the black wildebeest (C. gnou, Zimmermann, 1780). In recent years, forced sympatry in confined areas within South Africa has led to interbreeding between these taxa and to fertile hybrid offspring. Here we report on a series of cranial characteristics of a hybrid wildebeest population culled at Spioenkop Dam Nature Reserve, KwaZulu-Natal, South Africa. Dental, sutural and horn morphological anomalies occur at high frequency within these animals. Similar cranial morphological anomalies have been shown in other mammalian hybrids and this study provides further evidence that such anomalies may characterise hybridisation more broadly across phylogenetically divergent mammalian groups, although the anomalies appear to differ in their expression across taxa. An increased ability to identify hybrids may also have important applications in the conservation of the endemic black wildebeest.

Modern baboons evolved as a distinct lineage prior to 2.5 Mya. Previous scenarios of diversification within this lineage have assessed the phylogenetic position of the chacma baboon of southern Africa relative to other baboons, but have not examined variation within this taxon. Here we provide a phylogenetic analysis of lineage diversity across the range of the chacma baboon, and show that: (1) chacma baboons diverged as a separate lineage at approximately 1.84 Mya; (2) the chacma lineage is characterised by a deep lineage split dividing chacmas into northeastern (1.52 Mya) and southwestern (1.22 Mya) clades; (3) ruacana baboons of Namibia form their own distinct monophyletic group within the southwestern clade, emerging approximately 0.68 Mya. These patterns likely result from a complex interplay of genetic drift and gene flow as the chacma lineage diversified across a broad geographic landscape during the climatically variable Plio-Pleistocene.

Many questions about developmental divergence in human (and non-human primate) evolution can be fruitfully explored through investigation of the extant primate phenotype. Here I discuss two approaches that use patterns of variation in extant primates to consider hypotheses of 'tinkering' both in their own lineages, and also as applied to the fossil record of human evolution. In the first, I show how comparisons of ontogenetic morphological integration in extant humans and apes can be used to consider the developmental underpinnings of the morphological change seen in the transition from the prognathic australopith face to the relatively smaller, orthognathic Homo face. In the second approach, I demonstrate how studies of craniofacial variation in hybrid baboons can be used as models for considering developmental divergence in Plio-Pleistocene primates, including fossil hominins. Of particular interest is the fact that unusual non-metric dental and sutural variation in these hybrids appears to be a sensitive indicator of evolutionary developmental divergence. Future studies would profit from focusing on the breadth and especially the overlap of morphological variation among extant primate taxa in order to determine the degree to which underlying genetic similarity in functional regions, and difference in regulatory regions, explains the variable primate phenotype.

Erratum to Further evidence for phenotypic signatures of hybridization in descendent baboon populations [J. Hum. Evol. 76 (2014) 54e62] Rebecca R. Ackermann a, , Lauren Schroeder , Jeffrey Rogers , James M. Cheverud c a Department of Archaeology, University of Cape Town, Rondebosch 7701, South Africa b Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA c Department of Biology, Loyola University Chicago, Chicago, IL, USA