Chap man, C.; Fe di gan, L.M.; Fe di gan, L. 1988. A com pa ri son of trans ect me thods of es ti... more Chap man, C.; Fe di gan, L.M.; Fe di gan, L. 1988. A com pa ri son of trans ect me thods of es ti ma ting po pu la ti on den si ties of Costa Ri can pri ma tes. Bre ne sia 30: 67-80. Estra da, A.; Lue cke, L.; van Bel le, S.; Bar rue ta, E.; Ro sa les-Meda, M.
Abstract. The purpose of this application, under Articles 23.9. 3, 81.1 and 81.2. 3 of the Code, ... more Abstract. The purpose of this application, under Articles 23.9. 3, 81.1 and 81.2. 3 of the Code, is to conserve the name Pachylemur Lamberton, 1948 (Primates, LEMURIDAE), a genus of subfossil Malagasy lemurs, by suppressing the senior subjective synonym Palaeochirogalus Grandidier, 1899 and by designating a type species for the genus Pachylemur Lamberton.
Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of ... more Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of the availability of the generic name and for the nomenclatural validation of the journal in which it was published
Although the diminutive Homo floresiensis has been known for a decade, its phylogenetic status re... more Although the diminutive Homo floresiensis has been known for a decade, its phylogenetic status remains highly contentious. A broad range of potential explanations for the evolution of this species has been explored. One view is that H. floresiensis is derived from Asian Homo erectus that arrived on Flores and subsequently evolved a smaller body size, perhaps to survive the constrained resources they faced in a new island environment. Fossil remains of H. erectus, well known from Java, have not yet been discovered on Flores. The second hypothesis is that H. floresiensis is directly descended from an early Homo lineage with roots in Africa, such as Homo habilis; the third is that it is Homo sapiens with pathology. We use parsimony and Bayesian phylogenetic methods to test these hypotheses. Our phylogenetic data build upon those characters previously presented in support of these hypotheses by broadening the range of traits to include the crania, mandibles, dentition, and postcrania of Homo and Australopithecus. The new data and analyses support the hypothesis that H. floresiensis is an early Homo lineage: H. floresiensis is sister either to H. habilis alone or to a clade consisting of at least H. habilis, H. erectus, Homo ergaster, and H. sapiens. A close phylogenetic relationship between H. floresiensis and H. erectus or H. sapiens can be rejected; furthermore, most of the traits separating H. floresiensis from H. sapiens are not readily attributable to pathology (e.g., Down syndrome). The results suggest H. floresiensis is a long-surviving relict of an early (>1.75 Ma) hominin lineage and a hitherto unknown migration out of Africa, and not a recent derivative of either H. erectus or H. sapiens.
The phylogenetic pattern and timing of the radiation of Old World deer was determined based on th... more The phylogenetic pattern and timing of the radiation of Old World deer was determined based on the complete mitochondrial cytochrome b gene from 33 Cervinae taxa. Using rooted and unrooted phylogenies derived from distinct theoretical approaches, strong support was achieved for monophyly of the Old World deer with muntjacs as sister group as well as for the divergence of at least three distinct genera: Rucervus, Dama, and Cervus. The latter clade comprises what have previously been regarded as the genera or subgenera Panolia, Rusa, Cervus, Sika, and probably Przewalskium. Our data also consistently confirmed paraphyly of nominate C. elaphus and did not support the monophyly of Axis. We used these molecular phylogenies to assess the homoplastic evolution of morphological, geographical, ecological, and selected behavioural character state differences within the Cervinae. Reliable fossil calibrations, large molecular data sets, and improved dating methods are shaping a molecular time scale for the evolutionary radiation of Old World deer that occurred at the Miocene/Pliocene transition and is largely compatible with existing palaeontological evidence. Using node ages estimated from sequence data, we estimated an average per-lineage diversification rate of 0.51 ± 0.1 species per million years (my) over roughly the last 6 mya.
Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically d... more Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically distinguishable from those living in eastern central Africa (Gorilla beringei). Genomic analyses show eastern gorillas experienced a significant reduction in population size during the Pleistocene subsequent to geographical isolation from their western counterparts. However, how these results relate more specifically to the recent biogeographical and evolutionary history of eastern gorillas remains poorly understood. Here we show that two rare morphological traits are present in the hands and feet of both eastern gorilla subspecies at strikingly high frequencies (>60% in G. b. graueri; 28% in G. b. beringei) in comparison with western gorillas (<1%). The intrageneric distribution of these rare traits suggests that they became common among eastern gorillas after diverging from their western relatives during the early to middle Pleistocene. The extremely high frequencies observed among grauer gorillas—which currently occupy a geographic range more than ten times the size of that of mountain gorillas—imply that grauers originated relatively recently from a small founding population of eastern gorillas. Current paleoenvironmental, geological, and biogeo-graphical evidence supports the hypothesis that a small group of eastern gorillas likely dispersed westward from the Virungas into present-day grauer range in the highlands just north of Lake Kivu, either immediately before or directly after the Younger Dryas interval. We propose that as the lowland forests of central Africa expanded rapidly during the early Holocene, they became connected with the expanding highland forests along the Albertine Rift and enabled the descendants of this small group to widely disperse. The descendant populations significantly expanded their geographic range and population numbers relative to the gorillas of the Virunga Mountains and the Bwindi-Impenetrable Forest, ultimately resulting in the grauer gorilla subspecies recognized today. This founder-effect hypothesis offers some optimism for modern conservation efforts to save critically endangered eastern gorillas from extinction. Am J Phys Anthropol 159:S4
Titi monkeys, Callicebus, comprise the most species-rich primate genus-34 species are currently r... more Titi monkeys, Callicebus, comprise the most species-rich primate genus-34 species are currently recognised, five of them described since 2005. The lack of molecular data for titi monkeys has meant that little is known of their phylogenetic relationships and divergence times. To clarify their evolutionary history, we assembled a large molecular dataset by sequencing 20 nuclear and two mitochondrial loci for 15 species, including representatives from all recognised species groups. Phylogenetic relationships were inferred using concatenated maximum likelihood and Bayesian analyses, allowing us to evaluate the current taxonomic hypothesis for the genus. Our results show four distinct Callicebus clades, for the most part concordant with the currently recognised morphological species-groups-the torquatus group, the personatus group, the donacophilus group, and the moloch group. The cupreus and moloch groups are not monophyletic, and all species of the formerly recognized cupreus group are reassigned to the moloch group. Two of the major divergence events are dated to the Miocene. The torquatus group, the oldest radiation, diverged c. 11 Ma; and the Atlantic forest personatus group split from the ancestor of all donacophilus and moloch species at 9-8 Ma. There is little molecular evidence for the separation of Callicebus caligatus and C. dubius, and we suggest that C. dubius should be considered a junior synonym of a polymorphic C. caligatus. Considering molecular, morphological and biogeographic evidence, we propose a new genus level taxonomy for titi monkeys: Cheracebus n. gen. in the Orinoco, Negro and upper Amazon basins (torquatus group), Callicebus Thomas, 1903, in the Atlantic Forest (personatus group), and Plecturocebus n. gen. in the Amazon basin and Chaco region (donacophilus and moloch groups).
BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting... more BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.
The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harbor... more The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harboring cryptic species diversity. More comprehensive fieldwork combined with improvements in genetic research has revealed a larger radiation of species than was initially described in a number of lemur genera, including Avahi, Lepilemur, Microcebus, and Mirza. Available genetic and morphological evidence suggests that Cheirogaleus is among the genera where diversity was previously underestimated, and additional fieldwork may reveal even more species. A population of Cheirogaleus from northern Madagascar in and around Montagne d'Ambre National Park, surveyed during an expedition in 2005, was recently identified and proposed as a new species. Additional specimens were obtained during fieldwork in February of 2015. Subsequent genetic and morphological analyses of the data collected have determined that this population is an independent lineage, and herein we describe this new species, which we name Cheirogaleus andysabini after New York philanthropist Andy Sabin.
Historical climatic events and riverine barriers influence the distribution of primates. The Rive... more Historical climatic events and riverine barriers influence the distribution of primates. The River Congo exerts the most significant influence on primate distribution in equatorial Africa, but the extent to which the inner basin of the Congo provided a refuge against Plio-Pleistocene climatic fluctuation is poorly understood. In this study we use cranial and dental morphometrics to examine how riverine barriers affect population patterns in bonobos (Pan paniscus). Bonobos and chimpanzees (Pan troglodytes) are sister species and share the distinction of being the closest evolutionary relatives of humans, yet comparatively little is known about bonobo morphological diversity. We selected 55 adult bonobo crania with well-preserved postcanine dentitions and divided them into regions separated by the rivers Lukenie, Kasai, Lomami, and Lualaba. We found good discrimination among these regions in cranial and dental metrics, but whereas the discriminant functions from cranial metrics were statistically significant, the discriminant functions from dental metrics were not. Mean classification accuracy was 89% for craniometrics, and ranged between 72% and 93% for dental metrics. On average 84–97% of phenetic variation was encountered within regions. Our results mirrormolecular studies in suggesting that bonobos are characterized by a long-term stable demographic history allowing strong gene flow between regions and precluding drift and population differentiation. There are some indications that the bonobos from the Lomami-Lualaba and the Kasai-Sankuru regions are divergent, but modest sample sizes do not allow us to be conclusive.We would welcome the opportunity to work with field researchers to augment
our sample sizes and reanalyze our data.
The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harbor... more The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harboring cryptic species diversity. More comprehensive fieldwork combined with improvements in genetic research has revealed a larger radiation of species than was initially described in a number of lemur genera, including Avahi, Lepilemur, Microcebus, and Mirza. Available genetic and morphological evidence suggests that Cheirogaleus is among the genera where diversity was previously underestimated, and additional fieldwork may reveal even more species. A population of Cheirogaleus from northern Madagascar in and around Montagne d'Ambre National Park, surveyed during an expedition in 2005, was recently identified and proposed as a new species. Additional specimens were obtained during fieldwork in February of 2015. Subsequent genetic and morphological analyses of the data collected have determined that this population is an independent lineage, and herein we describe this new species, which we name Cheirogaleus andysabini after New York philanthropist Andy Sabin.
Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically d... more Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically distinguishable from those living in eastern central Africa (Gorilla beringei). Genomic analyses show eastern gorillas experienced a significant reduction in population size during the Pleistocene subsequent to geographical isolation from their western counterparts. However, how these results relate more specifically to the recent biogeographical and evolutionary history of eastern gorillas remains poorly understood. Here we show that two rare morphological traits are present in the hands and feet of both eastern gorilla subspecies at strikingly high frequencies (>60% in G. b. graueri; 28% in G. b. beringei) in comparison with western gorillas (<1%). The intrageneric distribution of these rare traits suggests that they became common among eastern gorillas after diverging from their western relatives during the early to middle Pleistocene. The extremely high frequencies observed among grauer gorillas—which currently occupy a geographic range more than ten times the size of that of mountain gorillas—imply that grauers originated relatively recently from a small founding population of eastern gorillas. Current paleoenvironmental, geological, and biogeographical evidence supports the hypothesis that a small group of eastern gorillas likely dispersed westward from the Virungas into present-day grauer range in the highlands just north of Lake Kivu, either immediately before or directly after the Younger Dryas interval. We propose that as the lowland forests of central Africa expanded rapidly during the early Holocene, they became connected with the expanding highland forests along the Albertine Rift and enabled the descendants of this small group to widely disperse. The descendant populations significantly expanded their geographic range and population numbers relative to the gorillas of the Virunga Mountains and the Bwindi- Impenetrable Forest, ultimately resulting in the grauer gorilla subspecies recognized today. This founder-effect hypothesis offers some optimism for modern conservation efforts to save critically endangered eastern gorillas from extinction.
Apes and Human Evolution Harvard University Press, Cambridge, MA and London, 2014, xiv + 1056 pp.... more Apes and Human Evolution Harvard University Press, Cambridge, MA and London, 2014, xiv + 1056 pp., ISBN 978-0-674-07316-6, $59.95, £44.95, €53.95 (Hardcover) Colin Groves
Several independent studies of acoustics, DNA, and morphology support the hypothesis of numerous ... more Several independent studies of acoustics, DNA, and morphology support the hypothesis of numerous cryptic sibling taxa within Tarsius tarsier (=spectrum), but direct comparison among studies is often hindered by the relative incomparability of specimens (e.g. those that measure acoustic form versus those that measure crania). Tail tufts have been used for taxonomic identification both among and within tarsier species groups,
Chap man, C.; Fe di gan, L.M.; Fe di gan, L. 1988. A com pa ri son of trans ect me thods of es ti... more Chap man, C.; Fe di gan, L.M.; Fe di gan, L. 1988. A com pa ri son of trans ect me thods of es ti ma ting po pu la ti on den si ties of Costa Ri can pri ma tes. Bre ne sia 30: 67-80. Estra da, A.; Lue cke, L.; van Bel le, S.; Bar rue ta, E.; Ro sa les-Meda, M.
Abstract. The purpose of this application, under Articles 23.9. 3, 81.1 and 81.2. 3 of the Code, ... more Abstract. The purpose of this application, under Articles 23.9. 3, 81.1 and 81.2. 3 of the Code, is to conserve the name Pachylemur Lamberton, 1948 (Primates, LEMURIDAE), a genus of subfossil Malagasy lemurs, by suppressing the senior subjective synonym Palaeochirogalus Grandidier, 1899 and by designating a type species for the genus Pachylemur Lamberton.
Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of ... more Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of the availability of the generic name and for the nomenclatural validation of the journal in which it was published
Although the diminutive Homo floresiensis has been known for a decade, its phylogenetic status re... more Although the diminutive Homo floresiensis has been known for a decade, its phylogenetic status remains highly contentious. A broad range of potential explanations for the evolution of this species has been explored. One view is that H. floresiensis is derived from Asian Homo erectus that arrived on Flores and subsequently evolved a smaller body size, perhaps to survive the constrained resources they faced in a new island environment. Fossil remains of H. erectus, well known from Java, have not yet been discovered on Flores. The second hypothesis is that H. floresiensis is directly descended from an early Homo lineage with roots in Africa, such as Homo habilis; the third is that it is Homo sapiens with pathology. We use parsimony and Bayesian phylogenetic methods to test these hypotheses. Our phylogenetic data build upon those characters previously presented in support of these hypotheses by broadening the range of traits to include the crania, mandibles, dentition, and postcrania of Homo and Australopithecus. The new data and analyses support the hypothesis that H. floresiensis is an early Homo lineage: H. floresiensis is sister either to H. habilis alone or to a clade consisting of at least H. habilis, H. erectus, Homo ergaster, and H. sapiens. A close phylogenetic relationship between H. floresiensis and H. erectus or H. sapiens can be rejected; furthermore, most of the traits separating H. floresiensis from H. sapiens are not readily attributable to pathology (e.g., Down syndrome). The results suggest H. floresiensis is a long-surviving relict of an early (>1.75 Ma) hominin lineage and a hitherto unknown migration out of Africa, and not a recent derivative of either H. erectus or H. sapiens.
The phylogenetic pattern and timing of the radiation of Old World deer was determined based on th... more The phylogenetic pattern and timing of the radiation of Old World deer was determined based on the complete mitochondrial cytochrome b gene from 33 Cervinae taxa. Using rooted and unrooted phylogenies derived from distinct theoretical approaches, strong support was achieved for monophyly of the Old World deer with muntjacs as sister group as well as for the divergence of at least three distinct genera: Rucervus, Dama, and Cervus. The latter clade comprises what have previously been regarded as the genera or subgenera Panolia, Rusa, Cervus, Sika, and probably Przewalskium. Our data also consistently confirmed paraphyly of nominate C. elaphus and did not support the monophyly of Axis. We used these molecular phylogenies to assess the homoplastic evolution of morphological, geographical, ecological, and selected behavioural character state differences within the Cervinae. Reliable fossil calibrations, large molecular data sets, and improved dating methods are shaping a molecular time scale for the evolutionary radiation of Old World deer that occurred at the Miocene/Pliocene transition and is largely compatible with existing palaeontological evidence. Using node ages estimated from sequence data, we estimated an average per-lineage diversification rate of 0.51 ± 0.1 species per million years (my) over roughly the last 6 mya.
Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically d... more Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically distinguishable from those living in eastern central Africa (Gorilla beringei). Genomic analyses show eastern gorillas experienced a significant reduction in population size during the Pleistocene subsequent to geographical isolation from their western counterparts. However, how these results relate more specifically to the recent biogeographical and evolutionary history of eastern gorillas remains poorly understood. Here we show that two rare morphological traits are present in the hands and feet of both eastern gorilla subspecies at strikingly high frequencies (>60% in G. b. graueri; 28% in G. b. beringei) in comparison with western gorillas (<1%). The intrageneric distribution of these rare traits suggests that they became common among eastern gorillas after diverging from their western relatives during the early to middle Pleistocene. The extremely high frequencies observed among grauer gorillas—which currently occupy a geographic range more than ten times the size of that of mountain gorillas—imply that grauers originated relatively recently from a small founding population of eastern gorillas. Current paleoenvironmental, geological, and biogeo-graphical evidence supports the hypothesis that a small group of eastern gorillas likely dispersed westward from the Virungas into present-day grauer range in the highlands just north of Lake Kivu, either immediately before or directly after the Younger Dryas interval. We propose that as the lowland forests of central Africa expanded rapidly during the early Holocene, they became connected with the expanding highland forests along the Albertine Rift and enabled the descendants of this small group to widely disperse. The descendant populations significantly expanded their geographic range and population numbers relative to the gorillas of the Virunga Mountains and the Bwindi-Impenetrable Forest, ultimately resulting in the grauer gorilla subspecies recognized today. This founder-effect hypothesis offers some optimism for modern conservation efforts to save critically endangered eastern gorillas from extinction. Am J Phys Anthropol 159:S4
Titi monkeys, Callicebus, comprise the most species-rich primate genus-34 species are currently r... more Titi monkeys, Callicebus, comprise the most species-rich primate genus-34 species are currently recognised, five of them described since 2005. The lack of molecular data for titi monkeys has meant that little is known of their phylogenetic relationships and divergence times. To clarify their evolutionary history, we assembled a large molecular dataset by sequencing 20 nuclear and two mitochondrial loci for 15 species, including representatives from all recognised species groups. Phylogenetic relationships were inferred using concatenated maximum likelihood and Bayesian analyses, allowing us to evaluate the current taxonomic hypothesis for the genus. Our results show four distinct Callicebus clades, for the most part concordant with the currently recognised morphological species-groups-the torquatus group, the personatus group, the donacophilus group, and the moloch group. The cupreus and moloch groups are not monophyletic, and all species of the formerly recognized cupreus group are reassigned to the moloch group. Two of the major divergence events are dated to the Miocene. The torquatus group, the oldest radiation, diverged c. 11 Ma; and the Atlantic forest personatus group split from the ancestor of all donacophilus and moloch species at 9-8 Ma. There is little molecular evidence for the separation of Callicebus caligatus and C. dubius, and we suggest that C. dubius should be considered a junior synonym of a polymorphic C. caligatus. Considering molecular, morphological and biogeographic evidence, we propose a new genus level taxonomy for titi monkeys: Cheracebus n. gen. in the Orinoco, Negro and upper Amazon basins (torquatus group), Callicebus Thomas, 1903, in the Atlantic Forest (personatus group), and Plecturocebus n. gen. in the Amazon basin and Chaco region (donacophilus and moloch groups).
BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting... more BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.
The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harbor... more The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harboring cryptic species diversity. More comprehensive fieldwork combined with improvements in genetic research has revealed a larger radiation of species than was initially described in a number of lemur genera, including Avahi, Lepilemur, Microcebus, and Mirza. Available genetic and morphological evidence suggests that Cheirogaleus is among the genera where diversity was previously underestimated, and additional fieldwork may reveal even more species. A population of Cheirogaleus from northern Madagascar in and around Montagne d'Ambre National Park, surveyed during an expedition in 2005, was recently identified and proposed as a new species. Additional specimens were obtained during fieldwork in February of 2015. Subsequent genetic and morphological analyses of the data collected have determined that this population is an independent lineage, and herein we describe this new species, which we name Cheirogaleus andysabini after New York philanthropist Andy Sabin.
Historical climatic events and riverine barriers influence the distribution of primates. The Rive... more Historical climatic events and riverine barriers influence the distribution of primates. The River Congo exerts the most significant influence on primate distribution in equatorial Africa, but the extent to which the inner basin of the Congo provided a refuge against Plio-Pleistocene climatic fluctuation is poorly understood. In this study we use cranial and dental morphometrics to examine how riverine barriers affect population patterns in bonobos (Pan paniscus). Bonobos and chimpanzees (Pan troglodytes) are sister species and share the distinction of being the closest evolutionary relatives of humans, yet comparatively little is known about bonobo morphological diversity. We selected 55 adult bonobo crania with well-preserved postcanine dentitions and divided them into regions separated by the rivers Lukenie, Kasai, Lomami, and Lualaba. We found good discrimination among these regions in cranial and dental metrics, but whereas the discriminant functions from cranial metrics were statistically significant, the discriminant functions from dental metrics were not. Mean classification accuracy was 89% for craniometrics, and ranged between 72% and 93% for dental metrics. On average 84–97% of phenetic variation was encountered within regions. Our results mirrormolecular studies in suggesting that bonobos are characterized by a long-term stable demographic history allowing strong gene flow between regions and precluding drift and population differentiation. There are some indications that the bonobos from the Lomami-Lualaba and the Kasai-Sankuru regions are divergent, but modest sample sizes do not allow us to be conclusive.We would welcome the opportunity to work with field researchers to augment
our sample sizes and reanalyze our data.
The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harbor... more The genus Cheirogaleus, the dwarf lemurs (Infraorder Lemuriformes), has been identified as harboring cryptic species diversity. More comprehensive fieldwork combined with improvements in genetic research has revealed a larger radiation of species than was initially described in a number of lemur genera, including Avahi, Lepilemur, Microcebus, and Mirza. Available genetic and morphological evidence suggests that Cheirogaleus is among the genera where diversity was previously underestimated, and additional fieldwork may reveal even more species. A population of Cheirogaleus from northern Madagascar in and around Montagne d'Ambre National Park, surveyed during an expedition in 2005, was recently identified and proposed as a new species. Additional specimens were obtained during fieldwork in February of 2015. Subsequent genetic and morphological analyses of the data collected have determined that this population is an independent lineage, and herein we describe this new species, which we name Cheirogaleus andysabini after New York philanthropist Andy Sabin.
Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically d... more Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically distinguishable from those living in eastern central Africa (Gorilla beringei). Genomic analyses show eastern gorillas experienced a significant reduction in population size during the Pleistocene subsequent to geographical isolation from their western counterparts. However, how these results relate more specifically to the recent biogeographical and evolutionary history of eastern gorillas remains poorly understood. Here we show that two rare morphological traits are present in the hands and feet of both eastern gorilla subspecies at strikingly high frequencies (>60% in G. b. graueri; 28% in G. b. beringei) in comparison with western gorillas (<1%). The intrageneric distribution of these rare traits suggests that they became common among eastern gorillas after diverging from their western relatives during the early to middle Pleistocene. The extremely high frequencies observed among grauer gorillas—which currently occupy a geographic range more than ten times the size of that of mountain gorillas—imply that grauers originated relatively recently from a small founding population of eastern gorillas. Current paleoenvironmental, geological, and biogeographical evidence supports the hypothesis that a small group of eastern gorillas likely dispersed westward from the Virungas into present-day grauer range in the highlands just north of Lake Kivu, either immediately before or directly after the Younger Dryas interval. We propose that as the lowland forests of central Africa expanded rapidly during the early Holocene, they became connected with the expanding highland forests along the Albertine Rift and enabled the descendants of this small group to widely disperse. The descendant populations significantly expanded their geographic range and population numbers relative to the gorillas of the Virunga Mountains and the Bwindi- Impenetrable Forest, ultimately resulting in the grauer gorilla subspecies recognized today. This founder-effect hypothesis offers some optimism for modern conservation efforts to save critically endangered eastern gorillas from extinction.
Apes and Human Evolution Harvard University Press, Cambridge, MA and London, 2014, xiv + 1056 pp.... more Apes and Human Evolution Harvard University Press, Cambridge, MA and London, 2014, xiv + 1056 pp., ISBN 978-0-674-07316-6, $59.95, £44.95, €53.95 (Hardcover) Colin Groves
Several independent studies of acoustics, DNA, and morphology support the hypothesis of numerous ... more Several independent studies of acoustics, DNA, and morphology support the hypothesis of numerous cryptic sibling taxa within Tarsius tarsier (=spectrum), but direct comparison among studies is often hindered by the relative incomparability of specimens (e.g. those that measure acoustic form versus those that measure crania). Tail tufts have been used for taxonomic identification both among and within tarsier species groups,
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Papers by Colin Groves
our sample sizes and reanalyze our data.
those living in eastern central Africa (Gorilla beringei). Genomic analyses show eastern gorillas experienced a significant
reduction in population size during the Pleistocene subsequent to geographical isolation from their western
counterparts. However, how these results relate more specifically to the recent biogeographical and evolutionary history
of eastern gorillas remains poorly understood. Here we show that two rare morphological traits are present in
the hands and feet of both eastern gorilla subspecies at strikingly high frequencies (>60% in G. b. graueri; 28% in
G. b. beringei) in comparison with western gorillas (<1%). The intrageneric distribution of these rare traits suggests
that they became common among eastern gorillas after diverging from their western relatives during the early to
middle Pleistocene. The extremely high frequencies observed among grauer gorillas—which currently occupy a geographic
range more than ten times the size of that of mountain gorillas—imply that grauers originated relatively
recently from a small founding population of eastern gorillas. Current paleoenvironmental, geological, and biogeographical
evidence supports the hypothesis that a small group of eastern gorillas likely dispersed westward from the
Virungas into present-day grauer range in the highlands just north of Lake Kivu, either immediately before or
directly after the Younger Dryas interval. We propose that as the lowland forests of central Africa expanded rapidly
during the early Holocene, they became connected with the expanding highland forests along the Albertine Rift and
enabled the descendants of this small group to widely disperse. The descendant populations significantly expanded
their geographic range and population numbers relative to the gorillas of the Virunga Mountains and the Bwindi-
Impenetrable Forest, ultimately resulting in the grauer gorilla subspecies recognized today. This founder-effect
hypothesis offers some optimism for modern conservation efforts to save critically endangered eastern gorillas from
extinction.
our sample sizes and reanalyze our data.
those living in eastern central Africa (Gorilla beringei). Genomic analyses show eastern gorillas experienced a significant
reduction in population size during the Pleistocene subsequent to geographical isolation from their western
counterparts. However, how these results relate more specifically to the recent biogeographical and evolutionary history
of eastern gorillas remains poorly understood. Here we show that two rare morphological traits are present in
the hands and feet of both eastern gorilla subspecies at strikingly high frequencies (>60% in G. b. graueri; 28% in
G. b. beringei) in comparison with western gorillas (<1%). The intrageneric distribution of these rare traits suggests
that they became common among eastern gorillas after diverging from their western relatives during the early to
middle Pleistocene. The extremely high frequencies observed among grauer gorillas—which currently occupy a geographic
range more than ten times the size of that of mountain gorillas—imply that grauers originated relatively
recently from a small founding population of eastern gorillas. Current paleoenvironmental, geological, and biogeographical
evidence supports the hypothesis that a small group of eastern gorillas likely dispersed westward from the
Virungas into present-day grauer range in the highlands just north of Lake Kivu, either immediately before or
directly after the Younger Dryas interval. We propose that as the lowland forests of central Africa expanded rapidly
during the early Holocene, they became connected with the expanding highland forests along the Albertine Rift and
enabled the descendants of this small group to widely disperse. The descendant populations significantly expanded
their geographic range and population numbers relative to the gorillas of the Virunga Mountains and the Bwindi-
Impenetrable Forest, ultimately resulting in the grauer gorilla subspecies recognized today. This founder-effect
hypothesis offers some optimism for modern conservation efforts to save critically endangered eastern gorillas from
extinction.