scispace - formally typeset
Search or ask a question
Author

Olga Otero

Bio: Olga Otero is an academic researcher from University of Poitiers. The author has contributed to research in topics: Neogene & Synodontis. The author has an hindex of 20, co-authored 59 publications receiving 2152 citations. Previous affiliations of Olga Otero include École normale supérieure de Lyon & Centre national de la recherche scientifique.


Papers
More filters
Journal ArticleDOI
11 Jul 2002-Nature
TL;DR: The discovery of six hominid specimens from Chad, central Africa, 2,500 km from the East African Rift Valley, suggest that the earliest members of the hominids clade were more widely distributed than has been thought, and that the divergence between the human and chimpanzee lineages was earlier than indicated by most molecular studies.
Abstract: The search for the earliest fossil evidence of the human lineage has been concentrated in East Africa. Here we report the discovery of six hominid specimens from Chad, central Africa, 2,500 km from the East African Rift Valley. The fossils include a nearly complete cranium and fragmentary lower jaws. The associated fauna suggest the fossils are between 6 and 7 million years old. The fossils display a unique mosaic of primitive and derived characters, and constitute a new genus and species of hominid. The distance from the Rift Valley, and the great antiquity of the fossils, suggest that the earliest members of the hominid clade were more widely distributed than has been thought, and that the divergence between the human and chimpanzee lineages was earlier than indicated by most molecular studies. From their initial description in 1925 1 until 1995, hominids from the Pliocene (5.3‐1.6 million years, Myr) and late Upper Miocene (,7.5‐5.3 Myr) were known only from southern and eastern Africa. This distribution led some authors to postulate an East African origin for the hominid clade (where the term ‘hominid’ refers to any member of that group more closely related to extant humans than to

831 citations

Journal ArticleDOI
11 Jul 2002-Nature
TL;DR: The fauna from Toros-Menalla site 266 suggests that S. tchadensis lived close to a lake, but not far from a sandy desert, perhaps the oldest record of desert conditions in the Neogene of northern central Africa.
Abstract: All six known specimens of the early hominid Sahelanthropus tchadensis come from Toros-Menalla site 266 (TM 266), a single locality in the Djurab Desert, northern Chad, central Africa. Here we present a preliminary analysis of the palaeontological and palaeoecological context of these finds. The rich fauna from TM 266 includes a significant aquatic component such as fish, crocodiles and amphibious mammals, alongside animals associated with gallery forest and savannah, such as primates, rodents, elephants, equids and bovids. The fauna suggests a biochronological age between 6 and 7 million years. Taken together with the sedimentological evidence, the fauna suggests that S. tchadensis lived close to a lake, but not far from a sandy desert, perhaps the oldest record of desert conditions in the Neogene of northern central Africa.

419 citations

Journal ArticleDOI
TL;DR: In this paper, the authors studied the ichthyofaunas of Thaytiniti and Taqah (Lower Oligocene, Sultanate of Oman) and As-Sarrar (Burdigalian, Saudi Arabia) with particular emphasis on palaeoenvironmental and palaeobiogeographic approaches.

86 citations

Journal ArticleDOI
TL;DR: The anatomical investigation of the osteology of both fossil and Recent species of the so-called Centropomidae was conducted with three aims: of improving the taxa definition, providing anatomical descriptions suitable for palaeontological studies and establishing a hypothesis for the phylogenetic relationships of the family.

61 citations

Journal ArticleDOI
TL;DR: In this paper, a new method for separation of Lu and Hf from apatite that involves a single extraction column step for Hf and a second exchange column stage for Lu is presented.

55 citations


Cited by
More filters
Journal ArticleDOI
01 Sep 2005-Nature
TL;DR: It is found that the patterns of evolution in human and chimpanzee protein-coding genes are highly correlated and dominated by the fixation of neutral and slightly deleterious alleles.
Abstract: Here we present a draft genome sequence of the common chimpanzee (Pan troglodytes). Through comparison with the human genome, we have generated a largely complete catalogue of the genetic differenc ...

2,267 citations

Journal ArticleDOI
01 Jun 2004-Genetics
TL;DR: A Markov chain Monte Carlo method for estimating the posterior probability distribution of model parameters is applied to a large multilocus data set from Drosophila pseudoobscura and D. persimilis, with considerable variation in gene flow estimates among loci, in both directions between the species.
Abstract: The genetic study of diverging, closely related populations is required for basic questions on demography and speciation, as well as for biodiversity and conservation research. However, it is often unclear whether divergence is due simply to separation or whether populations have also experienced gene flow. These questions can be addressed with a full model of population separation with gene flow, by applying a Markov chain Monte Carlo method for estimating the posterior probability distribution of model parameters. We have generalized this method and made it applicable to data from multiple unlinked loci. These loci can vary in their modes of inheritance, and inheritance scalars can be implemented either as constants or as parameters to be estimated. By treating inheritance scalars as parameters it is also possible to address variation among loci in the impact via linkage of recurrent selective sweeps or background selection. These methods are applied to a large multilocus data set from Drosophila pseudoobscura and D. persimilis. The species are estimated to have diverged ∼500,000 years ago. Several loci have nonzero estimates of gene flow since the initial separation of the species, with considerable variation in gene flow estimates among loci, in both directions between the species.

1,462 citations

Journal ArticleDOI
TL;DR: In this paper, the best dated and most complete African mammal fossil databases indicate African faunal assemblage and speciation changes during the Pliocene-Pleistocene interval (the last ca. 5.3 million years) were mediated by changes in African climate or shifts in climate variability.

1,127 citations

Journal Article
01 Jan 2011-PLOS ONE
TL;DR: The resolution of the primate phylogeny provides an essential evolutionary framework with far-reaching applications including: human selection and adaptation, global emergence of zoonotic diseases, mammalian comparative genomics, primate taxonomy, and conservation of endangered species.
Abstract: Comparative genomic analyses of primates offer considerable potential to define and understand the processes that mold, shape, and transform the human genome. However, primate taxonomy is both complex and controversial, with marginal unifying consensus of the evolutionary hierarchy of extant primate species. Here we provide new genomic sequence (,8 Mb) from 186 primates representing 61 (,90%) of the described genera, and we include outgroup species from Dermoptera, Scandentia, and Lagomorpha. The resultant phylogeny is exceptionally robust and illuminates events in primate evolution from ancient to recent, clarifying numerous taxonomic controversies and providing new data on human evolution. Ongoing speciation, reticulate evolution, ancient relic lineages, unequal rates of evolution, and disparate distributions of insertions/deletions among the reconstructed primate lineages are uncovered. Our resolution of the primate phylogeny provides an essential evolutionary framework with far-reaching applications including: human selection and adaptation, global emergence of zoonotic diseases, mammalian comparative genomics, primate taxonomy, and conservation of endangered species.

1,100 citations

Journal ArticleDOI
TL;DR: The authors provided new genomic sequence (,8 Mb) from 186 primates representing 61 (,90%) of the described genera, and included outgroup species from Dermoptera, Scandentia, and Lagomorpha.
Abstract: Comparative genomic analyses of primates offer considerable potential to define and understand the processes that mold, shape, and transform the human genome. However, primate taxonomy is both complex and controversial, with marginal unifying consensus of the evolutionary hierarchy of extant primate species. Here we provide new genomic sequence (,8 Mb) from 186 primates representing 61 (,90%) of the described genera, and we include outgroup species from Dermoptera, Scandentia, and Lagomorpha. The resultant phylogeny is exceptionally robust and illuminates events in primate evolution from ancient to recent, clarifying numerous taxonomic controversies and providing new data on human evolution. Ongoing speciation, reticulate evolution, ancient relic lineages, unequal rates of evolution, and disparate distributions of insertions/deletions among the reconstructed primate lineages are uncovered. Our resolution of the primate phylogeny provides an essential evolutionary framework with far-reaching applications including: human selection and adaptation, global emergence of zoonotic diseases, mammalian comparative genomics, primate taxonomy, and conservation of endangered species.

1,081 citations