Dr. Emily Casanova is a professor of Neuroscience and Psychology at Loyola University in New Orleans who studies autism, human/neanderthal hybridization, and sundry soft tissue disorders that are often co-inherited with autism. Her research has shown that autism spectrum disorders are underpinned by a complex network of genetic interactions whose first emergence can be traced back to human/neanderthal interbreeding nearly 40,000 years ago. This suggests that, contrary to popular belief, the grounds for autism spectrum disorders long predate the first diagnoses made in the early 20th century. We talk about why it’s so hard to come up with a genetic cause for autism, why “species” might not mean what we think it does, intricacies of embryogenesis, and why environmental causes are so hard to talk about.