Environmental Problems, Their Causes, and Sustainability 1

infrared radiation, as a rattlesnake can, or the ultravioletlight that guides some insects to their favoriteflowers.We cannot see as well or as far as an eagle or seewell in the night like some owls and other nocturnalcreatures. We cannot hear the high-pitched soundsthat help bats maneuver in the dark. Our ears cannotpick up low-pitched sounds that are the songs ofwhales as they glide through the world’s oceans. Wecannot smell as keenly as a dog or a wolf. By suchmeasures, our physical and sensory powers are pitiful.Yetwehave survived and flourished within lessthan a twitch of the earth’s 3.7-billion year evolutionaryhistory. Analysts attribute our success to two evolutionaryadaptations: a complex brain and strong opposablethumbs that allow us to grip and use tools better thanthe few other animals that have thumbs. This has enabledus to develop technologies that extend our limitedsenses, weapons, and protective devices.As a newly evolved infant species, we havequickly developed many powerful technologies totake over much of the earth’s life-support systems tomeet our basic needs and rapidly growing wants. Wenamed ourselves Homo sapiens sapiens—the doublywise species. If we keep degrading the life-supportsystem for us and other species, some say we shouldbe called Homo ignoramus—the unwise species. Duringthis century we will probably learn which of thesenames is appropriate.The good news is that we can change our ways. Wecan learn more about how to work with nature by understandingand copying the ways it has sustained itselffor several billion years despite major changes inenvironmental conditions.In the earth’s ballet of life that has been playing onthe global stage for about 3.7 billion years, life anddeath are interconnected. Some species appear andsome disappear, but the show goes on. We only recentlybecame members of this evolutionary ballet.Will we temporarily interrupt the show, take out someof the dancers, and get kicked off the stage? Or will welearn the rules of the ballet and have a long run? Welive in interesting and challenging times.All we have yet discovered is but a trifle in comparison withwhat lies hid in the great treasury of nature.ANTONI VAN LEEUWENHOEKCRITICAL THINKING1. (a) How would you respond to someone who tellsyou that he or she does not believe in biological evolutionbecause it is “just a theory”? (b) How would yourespond to a statement that we should not worry aboutair pollution because through natural selection thehuman species will develop lungs that can detoxifypollutants?2. How would you respond to someone who says thatbecause extinction is a natural process we should notworry about the loss of biodiversity?3. Describe the major differences between the ecologicalniches of humans and cockroaches. Are these two speciesin competition? If so, how do they manage to coexist?4. Explain why you are for or against each of the following:(a) requiring labels indicating the use of geneticallyengineered components in any food item, (b) using geneticengineering to develop “superior” human beings,and (c) using genetic engineering to eliminate aging anddeath.5. Suppose we could spray something in the air thatwould permanently give every person on earth unconditionallove for all other people and unconditional love fornature. Explain why you would favor or oppose doingthis. What professions, businesses, and educational subjectswould this eliminate? How would this affect the entertainment,sports, and advertising businesses? Howwould it affect politics and environmental professions?6. Congratulations! You are in charge of the future evolutionon the earth. What are the three most importantthings you would do?PROJECTS1. An important adaptation of humans is a strong opposablethumb, which allows us to grip and manipulatethings with our hands. As a demonstration of the importanceof this trait, fold each of your thumbs into the palmof its hand and then tape them securely in that position foran entire day. After the demonstration, make a list of thethings you could not do without the use of your thumbs.2. Use the library or the Internet to find out what controlsnow exist on genetically engineered organisms inthe United States, or the country where you live, andhow well such controls are enforced.3. Use the library or the Internet to find out bibliographicinformation about Charles Darwin and Antoni vanLeeuwenhoek, whose quotes appear at the beginning andend of this chapter.4. Make a concept map of this chapter’s major ideas, usingthe section heads, subheads, and key terms (in boldface).Look on the website for this book for informationabout making concept maps.LEARNING ONLINEThe website for this book contains study aids and manyideas for further reading and research. They include achapter summary, review questions for the entire chapter,flash cards for key terms and concepts, a multiple-choicepractice quiz, interesting Internet sites, references, and aguide for accessing thousands of InfoTrac ® College Editionarticles. Log on tohttp://biology.brookscole.com/miller14Then click on the Chapter-by-Chapter area, choose Chapter5, and select a learning resource.100 CHAPTER 5 Evolution and Biodiversity