If we still lived as hunters and gatherers on wild plums and animals alone, then there would be only about 25 million people on earth today. Now the population is over seven billion, which is due to a change in our way of life from over 10,000 years ago. Some of your and my ancestors saw the potential in certain wild plants and animals and started domesticating them. This happened through continuous cultivation and selection of those plants with a special capacity - only a small part of wild plants and animals can be domesticated at all. Let's have a look at this plant, for example. Isn't it amazing that out of this wild cabbage, kale, cauliflower and all the other cabbage varieties were developed? This development into a culture plant did, of course, not happen overnight but took thousands of years, and it took several hundreds of generations of humans. That's why they are a real cultural heritage, just like the Eiffel Tower or a Van Gogh painting. So, maybe the next time you bite into a cauliflower, be aware that you're eating a kind of Mona Lisa. (Laughter) Through domestication process, a huge diversity arose. For almost every part of the world, species and varieties that fit the special conditions were found. In Switzerland, for example, there were distinct varieties in almost every village, like the Küttiger carrot or the Uster apple. I like to watch the reactions of people at exhibitions of traditional varieties. It is clearly split by age. Older the people say, 'Oh, I remember this variety from my grandmother's garden.' And younger people, they are just amazed and say, 'I didn't know there were so many different ones', and then they take out their phone and take a picture. (Laughter) But apart from being a cultural heritage or simply being beautiful, do we really need this much diversity? Would not one single variety of each crop be enough? What happens if a population depends too much on a single variety was highlighted in Ireland in the mid 19th century. The Irish were mostly cultivating a potato variety called the Lumper. Potatoes of the same variety are clones and thus genetically identical. So when a new disease arrived with the potato blight, it had a very easy game, and it destroyed the crops in consecutive years. The sad consequence was that about a million people died, and one and a half million Irish had to emigrate. We can see from this that nature does not agree with monocultures, as they can be easily wiped out by a single disease. The natives in South America, for example, do not grow only one single potato variety but many, many different ones. Like this, they always have a yield, as the varieties differ in their reaction to pests and drier or wetter years. A more current example to show that monocultures are only short living is the banana. It may well be that in a few years, you will not be able to eat one anymore. The trade relies to 95 percent on a single variety which is grown on large plantations. These are now threatened by the Panama disease. There is no other variety to replace it at the moment. And to make my point for diversity very clear, let's look at it from a completely different angle. If you were so lucky to be a millionaire, you would not put all your money on the same stock, but you would diversify because the risk of losing everything is too big. But, in agriculture, instead of diversifying and minimising the risk, what we are doing is the exact opposite. And this funnel represents the concentration which is taking place at every level. Firstly, it represents the people working in agriculture. At the beginning of the 20th century, it was 60 percent of the population. Now, it is down to three percent. And it stands for the seed companies. In 1970, there were 7,000 companies, and none had a market share of over 0.5%. Now, the top five hold 60 percent of the market. And it stands for the huge loss in diversity. In the last 150 years, we lost 75 percent of all varieties ever selected by humans. They have gone forever. One reason for this huge loss is the industrialisation of every culture and with it the appearance of modern hybrid seeds. For farmers and gardeners, hybrid seeds are a dead end because they do not stay true to type when you take the seeds. You have to buy them every year, and thus, they are an extremely good business model, as you have to rely on the companies. Traditional varieties, on the other hand, can be regrown by everybody who wants to, year after year, by saving your own seeds. With traditional varieties, many ways are possible, and this is what makes them powerful. They can be the base for a more sustainable agricultural future. We do not know what challenges lie ahead and what new traits will be necessary, but the more diversity we can safeguard now, the better the chances are that we will have the suitable varieties  at hand for the future. And that is why I would like this funnel to be reversed again. With urban gardening and farming and community supported agriculture, reversing this process has already started. And that is why we from the ProSpecieRara Foundation try to save as many different traditional varieties as possible. At the moment we're safeguarding 1,600 different vegetable varieties in our seed library here in Basel, and the number is still growing. We think it's important to sow the seeds every year so that they can adapt to changing environment. We would need a very large garden to be able to do so, but fortunately, we have the help of over 500 volunteers who grow the varieties in their own garden and then send the saved seeds back to us. Without them, our work and that of other seed saving organisations would not be possible. You can also be part in reversing this process. To be honest, seed saving is quite difficult with most crops, but some are rather easy. Tomatoes, for example, are very simple and very rewarding. Have you ever eaten a sun-ripe tomato fresh from the plant? The taste of it excels  that of the supermarket type by far. And instead of eating only red and round ones, you can choose from a huge variety in color, shape and size. I'm sure you would find one that suits you. All you need is a sunny spot on your balcony or in front of your house, a pot, earth and water. When a tomato is ripe, the seeds are ripe as well. So if you want to get the seeds from a very good variety, you just put the seeds in a glass and let them sit for one or two days. Then you rinse them and let them dry. As nature is abundant, you will get a large amount of seeds, which you can share with your friends and family and resow next spring. By sowing and sharing them, you will keep a link alive to what your and my ancestors have been doing for thousands of years, and bring it into the future. I hope you will give it a try. Thank you. (Applause)