DNA of ancient wolf-dog pushes back domestication date

Over the past decade it has become increasingly clear that the fates of humans and dogs have been inextricably intertwined for millennia. Theories for where and when wolves began to associate with humans abound. Now DNA evidence extracted from the fossilized remains of a 35,000-year-old wolf-like animal indicates that the date of domestication was much earlier than previously estimated. Recent genome-based studies had suggested that the ancestors of modern dogs diverged from wolves about 16,000 years ago. Pontus Skoglund of Stockholm University, Sweden, and colleagues collected the fossilized rib and jawbone in 2010 during an expedition to the Taimyr Peninsula in Siberia. After radiocarbon dating the specimen, they compared its DNA with that of present-day wolves and dogs and found that the individual belonged to a population that had genetic similarities to both wolves and dogs. Examining mutation rates, the investigators concluded that the dog, wolf, and Taimyr genetic lineages all diverged at about the same time, far earlier than the previous best estimates for dog domestication. The study, published in the 1 June 2015 issue of Current Biology, suggests that genetic divergence occurred at least 27,000 years ago—perhaps as early as 40,000 years ago. The DNA evidence also showed that modern-day Siberian huskies and Greenland sled dogs share a large number of genes with the ancient wolf, which may have interbred with the ancestors of these modern-day dogs. The investigators suggest that these ancient ancestors of dogs maintained wolf-like behavior and may simply have tracked human populations for many thousands of years before humans began the selective breeding process that created companion animals. —Karyn Hede, News Editor

Harnessing the power of “massively parallel” undergraduates

It looks like an authorship list gone wild, but a recent genomics research article published in the May issue of G3: GenesGenomesGenetics listed 940 undergraduate students as authors on a peer-reviewed scientific paper. And this was no token authorship; each of the 940 students listed as coauthors performed original research and read and approved the manuscript before submission, according to a report on the research by the Genetics Society of America. Many of the students also provided important comments that were incorporated into the final version, the report stated. The research team, led by researchers at Washington University, St. Louis, included students at 63 institutions. The study revealed that the distinctive properties of a tiny chromosome in the common laboratory strain of fruit fly, Drosophila melanogaster, are conserved across other Drosophila species. The work required enough genomics knowledge and bioinformatics skills to correct sequencing errors in the draft genomes of several fly species. The investigators distributed the work among groups of students coordinated by the Genomics Education Partnership (GEP) in a program aimed at exposing undergraduates to research. The GEP found that the students learned more than those who did not participate in a research-based genomics course, including the ability to analyze data and understand the research process. “By organizing the efforts of “massively parallel” undergrads, we can solve problems that would defeat other methods,” according to Sarah Elgin, GEP program leader. “At the same time, students learn how to handle the messiness of real data, to evaluate different kinds of evidence, and to justify their conclusions.” The immersive research experience is funded by educational grants from the Howard Hughes Medical Institute and the National Science Foundation. —Karyn Hede, News Editor