thousands of years and used in traditional cultures, rituals and customs. Another example are local food fairs, epitomized by the Slow Food movement, which celebrates local food varieties in order to add value to them, raise awareness about them and ultimately conserve and use them. In addition, some traditional cultures use agrobiodiversity in cultural rituals, e.g. many populations of fruit species (pomelo and mango) are maintained in rural communities specifically for use at the 'Chhath Puja' festival, celebrated in parts of India, Nepal and Mauritius. Home gardens are important as culturally constructed spaces where agrobiodiversity is conserved for a wide variety of social, aesthetic and cultural reasons. Genetic diversity is maintained by resource-poor farmers because of many non-monetary values, including culture and food. Loss of agrobiodiversity Agrobiodiversity is threatened by changing patterns of land use (urbanization, deforestation), agricultural modernization (monocultures and abandoning of traditional, biodiversity-based practices); Westernization of diets and their supply chains. It has been estimated that biodiversity as a whole is being lost at 100–1000 times the natural background rate. This extends also to agricultural biodiversity and loss of genetic diversity from farmers' fields and the wild. Agrobiodiversity loss leads to genetic erosion, the loss of genetic diversity, including the loss of individual genes, and the loss of particular combinations of genes (or gene complexes) such as those manifested in locally adapted landraces or breeds. Genetic vulnerability occurs when there is little genetic diversity within a population of plants. This lack of diversity makes the population as a whole particularly vulnerable to disease, pests, or other factors. The problem of genetic vulnerability often arises with modern crop varieties, which are uniform by design. An example of the consequences of genetic vulnerability occurred in 1970 when corn blight struck the US corn belt, destroying 15% of the harvest. A particular plant cell characteristic known as Texas male sterile cytoplasm conferred vulnerability to the blight - a subsequent study by the National Academy of Sciences found that 90% of American maize plants carried this trait. Reduced agrobiodiversity influences, and is influenced by, changes in human diets. Since the mid-1900s, human diets across the world have become more diverse in the consumption of major commodity staple crops, with a corollary decline in consumption of local or regionally important crops, and thus have become more homogeneous globally. The differences between the foods eaten in different countries decreased by 68% between 1961 and