根据以下资料回答第39、40题。
 Edward Wilson is America's, if not the world's, leading naturalist.In The Future of Life, hetakes us on a tour of the world's natural resources(资源).How are they used? What has beenlost? What remains and is it able to continue with the present speed of use.'? Wilson also points outthe need to understand fully the biodiversity( 生物多样性) of our earth. 
Wilson begins with an open letter to the pioneer in environment(环境) protection,Henry David Thoreau.He compares today's Walden Pond with that of Thoreau's day.Wilson willuse such comparisons for the rest of the book.The problem is clear: man has done great damage tohis home over the years.Can the earth, with human help, be made to return to biodiversity levels thatwill be able to support us in the future? 
Biodiversity, Wilson argues, is the key to settling many problems the earth faces today.Even ouragricultural crops can gain advantages from it.A mere hundred species(物种) are the basis of ourfood supply, of which but twenty carry the load.Wilson suggests changing this situation by lookinginto ten thousand species that could be made use of, which will be a way to reduce the clearing ofthe natural homes of plants and animals to enlarge farming areas. 
At the end of the book, Wilson discusses the importance of human values in considering theenvironment.If you are to continue to live on the earth, you may well read and act on the ideas inthis book.
We learn from the text that Wilson cares most about______.