ABSTRACT
The geographic and temporal origins of the domestic dog remain controversial, as genetic data suggest a domestication process in East Asia beginning 15,000 years ago, whereas the oldest doglike fossils are found in Europe and Siberia and date to >30,000 years ago. We analyzed the mitochondrial genomes of 18 prehistoric canids from Eurasia and the New World, along with a comprehensive panel of modern dogs and wolves. The mitochondrial genomes of all modern dogs are phylogenetically most closely related to either ancient or modern canids of Europe. Molecular dating suggests an onset of domestication there 18,800 to 32,100 years ago. These findings imply that domestic dogs are the culmination of a process that initiated with European hunter-gatherers and the canids with whom they interacted.
Subject(s)
Animals, Domestic/genetics , Dogs/genetics , Genome, Mitochondrial/genetics , Animals , Base Sequence , Breeding , Europe , Molecular Sequence Data , Phylogeny , Wolves/geneticsABSTRACT
The DNA sequence of the second hypervariable region of the mitochondrial control region of the Neandertal type specimen, found in 1856 in central Europe, has been determined from 92 clones derived from eight overlapping amplifications performed from four independent extracts. When the reconstructed sequence is analyzed together with the previously determined DNA sequence from the first hypervariable region, the Neandertal mtDNA is found to fall outside a phylogenetic tree relating the mtDNAs of contemporary humans. The date of divergence between the mtDNAs of the Neandertal and contemporary humans is estimated to 465,000 years before the present, with confidence limits of 317,000 and 741,000 years. Taken together, the results support the concept that the Neandertal mtDNA evolved separately from that of modern humans for a substantial amount of time and lends no support to the idea that they contributed mtDNA to contemporary modern humans.
Subject(s)
DNA, Mitochondrial/genetics , Hominidae/genetics , Amino Acid Sequence , Animals , Biological Evolution , Fossils , Gene Pool , Humans , Molecular Sequence Data , Paleontology , Phylogeny , Polymerase Chain Reaction , Sequence Homology, Nucleic AcidABSTRACT
DNA was extracted from the Neandertal-type specimen found in 1856 in western Germany. By sequencing clones from short overlapping PCR products, a hitherto unknown mitochondrial (mt) DNA sequence was determined. Multiple controls indicate that this sequence is endogenous to the fossil. Sequence comparisons with human mtDNA sequences, as well as phylogenetic analyses, show that the Neandertal sequence falls outside the variation of modern humans. Furthermore, the age of the common ancestor of the Neandertal and modern human mtDNAs is estimated to be four times greater than that of the common ancestor of human mtDNAs. This suggests that Neandertals went extinct without contributing mtDNA to modern humans.
Subject(s)
Bone and Bones/chemistry , DNA, Mitochondrial/chemistry , Evolution, Molecular , Fossils , Hominidae/genetics , Phylogeny , Animals , Base Sequence , Cloning, Molecular/methods , DNA Primers , DNA, Mitochondrial/genetics , DNA, Mitochondrial/isolation & purification , Genetic Variation , Germany , Humans , Humerus/chemistry , Molecular Sequence Data , Polymerase Chain Reaction/methods , Reproducibility of Results , Sequence Homology, Nucleic AcidABSTRACT
Seventeen patients with dimples, fistulae and cysts in the region of the cheek and the preauricular field are reported. All are located in the neighborhood of the dorsal end of the first visceral arch. Both the fistulae of the ascending helix and the upper preauricular fistulae must be regarded as relics of the dorsal end of the first branchial cleft. This interpretation supports the theory of Wood-Jones and I-Chuan according to which the tragus is formed from the material of the mandibular arch, and the remaining part of the auricle from the mesoderm of the second visceral arch. Similar anomalies in the neighborhood of the angle of the mouth, the extraoral opening of an accessory duct of Stensen and the inferior preauricular fistula are sufficiently explained by the incomplete closure or tearing of the embryonal oral aperture.
