 This is classical genetics. Some people wonder what is the difference between classical genetics and molecular genetics? Is it a historical difference? Well, yes. Classical genetics was developed by Gregor Mendel in the late 19th century and, of course, molecular genetics involves everything that we know about the DNA molecule after its structure was understood by Watson and Crick. But in addition to the historical differences, there's also kind of a hierarchical difference. Classical genetics focuses on everything at the level of the chromosome and above, things that we can see through the microscope and with our naked eyes, this physical structure of chromosomes. You know, chromosomes are supercoiled strings of DNA that have a very complex structure. They open for expression. There are many of them in a cell. We can lose chromosomes and that can cause problems. When chromosomes bang into each other at the beginning of meiosis, they can even exchange their tips, generating lots of variation. Now we'll be tracing this variation in genes and, of course, in the traits that they confer across the generations by looking at pedigrees. Pedigrees help us understand the inheritance of disease-causing genes throughout human families, but they also inform our plant and animal breeding programs. We'll be focusing a little bit on one of my favorite plant breeders, Norma Borlaug, who won the Nobel Prize in the few decades ago for developing varieties of wheat that doubled and tripled grain productions across Asia, forestalling a real starvation crisis for our global civilization. We'll also be focusing on population genetics. And population genetics is when you track the inheritance of genes and traits across, not just across the generations, like in a family, but within a population. And this is really the mathematical foundation for our modern understanding of evolution. And we'll be tracing the evolution of species and of genes within that species in some of our favorite animals, like humans. Well, anyway, I'm really looking forward to the class and I hope you'll enjoy it as well.