Hi Reddit, My name is Ronnie Sebro and I am an Assistant Professor in Genetics and Radiology at the University of Pennsylvania. As a statistical geneticist and radiologist, my research interests center around genetic analysis of quantitative imaging phenotypes. More recently, I have been exploring the impact of non-random mating on genetic association studies. I recently published a study “Structured mating: Patterns and implications” in PLOS Genetics in conjunction with collaborators at the University of California, San Francisco and Boston University School of Public Health. The aim of the study was to assess how the mating patterns in a European-American population changed over time (over 3 generations, starting in 1948) and to discuss the implication of these findings for current genetic studies. We found there were primarily three clusters of individuals – those with Northern/European ancestry, those with Southern European ancestry and those with Ashkenazi Jewish ancestry. In the first generation, we found that individuals were more likely to choose spouses with similar genetic ancestry (i.e. from the same cluster), however the strength of this association decreased with each successive generation, suggesting gradual intermixing between clusters. Some of the physical and behavioral similarities seen between spouses may be as a result of their similar genetic ancestry. I will be answering your questions at 1pm ET – Ask me Anything!