Make your own free website on

Silent Spring's AP Biology

Silent Spring by Rachel Carson covers the effects of pesticides and herbicides on the environment. A key piece during its time, the book cites about 500 principle sources in the course of 297 pages. Its coverage of the effects of pesticides, although filled with loaded and biased terminology, is thorough and explains the physiological effects of the pesticides and herbicides. Its explanations are plausible and relate well to the AP Biology curriculum despite its subtly charged tone. Carson outlines both the function of the liver, the ability of certain pesticides to emulate sex hormones, and the inhibition of cellular division by pesticides.

Carson outlines the function of the human liver as an organ which provides "bile for the digestion of fats ... is deeply involved in the metabolism of all principle foodstuffs ... stores sugar ... and releases [sugar] as glucose ... builds body proteins ... maintains cholesterol at the proper level ..." and stores many vitamins in addition to detoxifying many chemicals (Carson 191). The liver, discussed in our text with digestion, aids in digestion. In Chapter 37, Wallace more specifically enumerates the functions of liver and its bile in two paragraphs (Wallace 800). Also in Chapter 36, the liver is outlined in the discussion of insulin and glucagon (Wallace 779). Thus when Carson begins to discuss liver poisons and cirrhosis, the AP Biology student, as well as anyone who read Carson's thorough treatment of the liver's manifold functions, will understand the impact of pesticides.

Carson also makes reference to cell division as method of function. Carson mentions phenols, carbamates, benzene hexachloride (BHC), and 2,4-D which all interfere with cell duplication (Carson 213). Given extensive study of the cell cycle in Wallace's text's chapter 9, AP Biology students will note the doubling of chromosomes as part of the S phase in cellular reproduction (Wallace 202). "[The BHC treated plant] cells grew in size, being swollen with chromosomes which doubled in number. The doubling continued in future divisions until further cell division became mechanically impossible" (ibid.). Thus the AP Biology syllabus meshes well with Carson's reference and adds appropriate tangential details.

Carson elaborates on the AP Biology view of sex hormones. She notes, "the sex hormones are, of course, normally present in the body and perform a necessary growth-stimulating function in relation to the various organs of reproduction. But the body has a built-in protection against excessive accumulations, for the liver acts to keep a proper balance between male and female hormones ..." (Carson 235-236). Thus she, neglecting the extensive feedback loops documented in Wallace's Chapter 41, cuts straight to the dangers of excessive levels of estrogen. She cites McGill University's study which finds that high estrogen cause uterine cancer. She goes on to explain the liver's role and the role of vitamin B in removal of estrogen. Again, Carson has gone beyond the AP Biology Curriculum which serve as a mere tangential fact base for the extreme conditions that arise from pesticide and insecticide use. Silent Spring covers much of biology while exploring the impact of pesticides and insecticides.

Carson, Rachel. Silent Spring. Boston: Houghton Mifflin Company, 1962.

Wallace, Robert A. and Gerald P. Sanders and Robert J. Ferl. Biology: The Science of Life. 4th ed. Harper Collins College Publishers, 1996.