This week's lecture is a bit risky for me. I'm gonna deal with a subject that on the one hand has incredible scientific and technological potential to impact the world. But on the other hands, it enlists in many people a very strong negative emotional response. Today, we're gonna learn about genetic engineering in plants. Now I know that some of you are skeptics, but I ask that you give me the benefit of the doubt for the next hour or so. As we learn about the science behind genetic engineering implants or what some people refer to as GMOs. First, we'll cover what genetic modification of crops is in the old world today asking the question, what's natural? Then we'll learn about the technology of genetic engineering and then we'll briefly touch on some of the economic and social issues involved including the question, is it safe? So let's just remember that life on Earth is about 4 billion years old. But we as homo sapiens, our own species, emerged only about 300,000 years ago. In these 300,000 years, human activities have caused vast changes in the physical, chemical, geological, atmospheric and biological realm of our planet. This includes modifying species in extraordinary ways. We only have to look at the wild wolf and its domesticated relatives of dogs to see how people have influenced the evolution of canines. The great Dane or the chihuahua are quite different from the wild wolf. These species could not survive in the wild, but they survive quite happily in our homes, because we've domesticated these animals. These are genetic modifications that we, as people selected for in dogs. We've also modified plant genomes for thousands of years. For example, I'm not sure that most of you know that even several hundred years ago carrots were not orange, but there's a vast diversity in the color of carrots that we as humans have selected for in agriculture. And this effects all the plants that we know about that we've cultivated, but now we face our biggest challenges. How do we feed a growing planet without further damaging our ecosystems? It's not surprising we know that the world population is exploding. When I was born, there was only 3 billion people in the world. When my parents were born, only 2 billion people and now we're some where around 7 billion and most of the models have us topping out by 2050 at around 9 billion people and most of this growth in population is in the developing world. At the same that there is this huge growth in population, we see a decrease in the amount of arable land available for agriculture. Land available for agriculture is decreasing by over a 100,000 square kilometers per year. This makes sense. As there are more people in the world, we need more land for housing. This leaves less land available for agriculture. The projections are that while 24% of the Earth's surface today is arable, less than 20% will be arable by 2050. So how have we managed though to feed the world with this huge increase in population, but with a decrease in arable land? Well, the way we've done it over the past century is that each year, there have been gains in yields per acre. Each year, we're having more wheat yields, more corn yields, more rice yields per acre, but these gains and yields are decreasing. We're seeing yields starting to plateau. And so if we look at world cereal production today and most of our calories come from cereals is about 2,000 kilocalories per person per day. To maintain this level, we'll have to increase yields by over 30% by the year 2025 and we're gonna have to do this with less land. We're gonna have to do this with less water. We're gonna have to do this with less fertilizers, because some of our fertilizers, for example, such as phosphates are not renewable. We're gonna have to do this in a world that's getting hotter where we're having severe climate changes, but I'm not telling you this to depress you. Actually, I'm pretty sure that we will succeed in doing this. Even though the population has increased two-fold since I was born, there is proportionally less hunger in the world today than ever in the history of mankind, but still about 800 million people do go hungry each day. So how will we continue to feeding a growing population? We need a toolbox of answers, but one of the tools in this toolbox is genetic engineering.