Grey wolf genomic history reveals a dual ancestry of dogs

The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived^1–8. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000–30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located.

DNA from ancient wolves spanning 100,000 years sheds light on wolves’ evolutionary history and the genomic origin of dogs.

Where myth and archaeology meet: Discovering the Gorgon Medusa's Lair

Here we report the discovery of ceramic fragments that form part of a Gorgoneion, a ceramic image representation of the Gorgon Medusa. The fragments were found in a deep part of Gorham’s Cave, well known to ancient mariners as a natural shrine, between the 8^th and 2^nd century BCE. We discuss the context of this discovery, both within the inner topography of the cave itself, and also the broader geographical context. The discovery is situated at the extreme western end of the Mediterranean Sea, where it meets the Atlantic Ocean. The location was known to ancient mariners as the northern Pillar of Herakles, which marked the end of the known world. We relate the discovery, and its geographical and chronological context, to Greek legends that situated the lair of the Gorgon sisters at a location which coincides with the physical attributes and geographical position of Gorham’s Cave. We thus provide, uniquely, a geographical and archaeological context to the myth of Perseus and the slaying of the Gorgon Medusa.

Correction: Acheulean technology and landscape use at Dawadmi, central Arabia

[This corrects the article DOI: 10.1371/journal.pone.0200497.].

Acheulean technology and landscape use at Dawadmi, central Arabia

Despite occupying a central geographic position, investigations of hominin populations in the Arabian Peninsula during the Lower Palaeolithic period are rare. The colonization of Eurasia below 55 degrees latitude indicates the success of the genus Homo in the Early and Middle Pleistocene, but the extent to which these hominins were capable of innovative and novel behavioural adaptations to engage with mid-latitude environments is unclear. Here we describe new field investigations at the Saffaqah locality (206–76) near Dawadmi, in central Arabia that aim to establish how hominins adapted to this region. The site is located in the interior of Arabia over 500 km from both the Red Sea and the Gulf, and at the headwaters of two major extinct river systems that were likely used by Acheulean hominins to cross the Peninsula. Saffaqah is one of the largest Acheulean sites in Arabia with nearly a million artefacts estimated to occur on the surface, and it is also the first to yield stratified deposits containing abundant artefacts. It is situated in the unusual setting of a dense and well-preserved landscape of Acheulean localities, with sites and isolated artefacts occurring regularly for tens of kilometres in every direction. We describe both previous and recent excavations at Saffaqah and its large lithic assemblage. We analyse thousands of artefacts from excavated and surface contexts, including giant andesite cores and flakes, smaller cores and retouched artefacts, as well as handaxes and cleavers. Technological assessment of stratified lithics and those from systematic survey, enable the reconstruction of stone tool life histories. The Acheulean hominins at Dawadmi were strong and skilful, with their adaptation evidently successful for some time. However, these biface-makers were also technologically conservative, and used least-effort strategies of resource procurement and tool transport. Ultimately, central Arabia was depopulated, likely in the face of environmental deterioration in the form of increasing aridity.

Rethinking the dispersal of Homo sapiens out of Africa

Current fossil, genetic, and archeological data indicate that Homo sapiens originated in Africa in the late Middle Pleistocene. By the end of the Late Pleistocene, our species was distributed across every continent except Antarctica, setting the foundations for the subsequent demographic and cultural changes of the Holocene. The intervening processes remain intensely debated and a key theme in hominin evolutionary studies. We review archeological, fossil, environmental, and genetic data to evaluate the current state of knowledge on the dispersal of Homo sapiens out of Africa. The emerging picture of the dispersal process suggests dynamic behavioral variability, complex interactions between populations, and an intricate genetic and cultural legacy. This evolutionary and historical complexity challenges simple narratives and suggests that hybrid models and the testing of explicit hypotheses are required to understand the expansion of Homo sapiens into Eurasia.

Results of surgical treatment for Menière's disease

In 1985 the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium established revised guidelines for reporting treatment results for Menière's disease. Since then little information regarding the newly adapted criteria and their effects on the evaluation process has appeared. Thus we compared the results of different surgical procedures for Menière's disease using both the 1985 and 1972 guidelines. One hundred nine surgical procedures from 1969 to 1985 were reviewed. Six different surgical procedures were evaluated: the Cody-Tack, cochleosacculotomy, endolymphatic mastoid shunt, endolymphatic subarachnoid shunt, translabyrinthine vestibular nerve section, and transcanal labyrinthectomy. Results show that 68% of patients who had a Cody-Tack procedure continued to have vertiginous episodes in the same frequency postoperatively. Hearing was worse in 17 of these 25 patients. Of the patients who had a cochleosacculotomy, most had significant control of their vertiginous symptoms, but 10 patients had greater than 10 dB hearing loss postoperatively. Patients who had an endolymphatic mastoid shunt performed had better results when the 1972 guidelines were applied. In this group, the 1985 guidelines indicate that only 35% of the patients had significant relief of their vertiginous symptoms and 47% had hearing loss greater than 10 dB postoperatively. Six of the seven patients who underwent an endolymphatic subarachnoid shunt obtained significant relief of their vertiginous episodes, but hearing loss was more than 10 dB in four patients. Those patients who had either a labyrinthectomy or a translabyrinthine vestibular nerve section had relief of their vertiginous episodes. We conclude that the new guidelines appear to be superior to the 1972 guidelines for reporting results for the treatment of Menière's disease.