The Human Genome Project (HGP) was begun in 1990 and declared complete in 2003. It has revolutionized our understanding of genetics and will ultimately revolutionize medical practice. In my opinion, every educated citizen should know some basic findings from the HGP. This week’s lectures provide an introduction to molecular biology and the HGP. We will cover topics such as: What is DNA? What is a gene and how are genes structured? In what ways can human genomes differ? What is epigenetics and why do some researchers believe it is very important for understanding behavior? As in previous lectures, I will illustrate some of the basic human genetic phenomena through case studies, in this case ranging from calico cats to the human genetic disorders of Angelman and Prader-Willi syndromes. This week’s lectures continue what we began last week: laying the foundation of genetic concepts and processes we will need to consider in some depth genetic research on schizophrenia and intelligence. Some participants in this course already have an extensive background in basic genetics and so will be very knowledgeable about material covered in the initial modules. But I think even these participants will have something to learn when we get to the later modules in the unit covering, e.g., Williams Syndrome, Prader-Willi Syndrome and Angelman Syndrome. For those with a more limited background in genetics, I recognize that the terminology introduced this week may at first seem a bit daunting. But if you stick with it, terms such as SNPs, methylation, exon, copy number variants, etc. which seem foreign now will become consolidated in your vocabulary through repeated use throughout the remaining lectures in this course. There are several learning aids I would encourage you to use. First, we have created a Glossay, which you can link to off the navigation bar on the course website. Second, the Discussion Forums are a wonderful source of help. Other participants can be very helpful in answering your questions and a post in the Office Hours thread will be reviewed by us for response in the weekly office hour video. Finally, we give again online genetics education links in the Other Resources section below.