生命的奥秘，超越自然选择的边界。东北往事txt

　　Earth teems with a staggering variety of animals, including 9,000 kinds of birds, 28,000 types of fish, and more than 350,000 species of beetles. What explains this explosion of living creatures—1.4 million different species discovered so far, with perhaps another 50 million to go? The source of life's endless forms was a profound mystery until Charles Darwin brought forth his ... (展开全部)