we now have the dollar, and we used to have the sucre. ♪ >> which country would you llike to visit?ted states or spain. one of the two would be good. ♪ my daughter has lived in spain for several years. and i have cousins living in the united states. ♪ >> now those medicinal herbs , that emperatriz sells might not be around at all were it not for butterflies, bees, beetles, and other creatures. should one of those species become extinct, the consequences for the rest of the ecosystem could be catastrophic. our reporter maria lesser uses the humble butterfly to illustrate the importance of biodiversity, and how animals, plants, and humans depend on each other. >> up to 14 million species inhabit our planet. animals, plants, fungi, and microorganisms. but do we need them all? butterflies, for example. biologists have identified around 180,000 different species. they can be found here, and here, and here, too. they look very different, and are also different in terms of many of their genes. genetic diversity helps species to adapt to environmental change and survive. and that ensures th