Course Icon

Natural Science - Year II

Unit 57: Natural History and Ecology

SO Icon

History Weblecture for Unit 57

This Unit's Homework Page History Lecture Science Lecture Lab Parents' Notes

History Lecture for Unit 57: The Conservation of Nature

For Class


The Naturalists

The two major advances in biology during the twentieth century have both emphasized the common features which characterize all life on earth. This week, we look at the developing concept of the environment and our growing realization that not only do most living things interact with the environment and each other, they are also interdependent. Over the next three weeks, we will look at the discoveries of the processes of photosynthesis, cellular respiration, and cell reproduction, working our way from the large context of the interaction of populations of individual organisms with their environment and each other to the details of individual molecules.

When the first Europeans came to the American continent, they saw the wilderness in many different ways. For some, both the wilderness and the native Americans were untouched by the corrupting civilization of the Old World, and should be carefully studied. For others, the wilderness was the abode of evil, to be tamed and civilized. And for still others, it was neither particularly good or bad, but full of endless resources to be used without fear of shortage.

During the nineteenth centuries, explorers and settlers realized that their infiltration into the wilderness was changing it and, in some areas, destroying it. Attitudes toward the wilderness changed, and people became interested in at least recording the passing of the frontier. The naturalist worked as a collector and observer of nature in the field. Often working outside the academic professions or labs, many naturalists had a difficult time winning recognition of the scientific value of their observations.

John James Audubon

The art works of John James Audubon brought the beauty of America's birds to its urban East Coast and to Europe--but Audubon was not seriously concerned with conservation efforts until near the end of his life. He found the birds and mammals of the new world curious, fascinating, and well worth drawing.

Read about John James Audubon at the Audubon Society's Web Page [1 brief web page (biography)]. Then read the more detailed description of Audubon's work in Florida (with illustrations) at the Historical Museum of Southern Florida. [10 very short web pages with graphics (Birds of America)]

[If the Audubon site pages are not unavailable, take a look at the New World Encyclopedia article.]

  • Why was it difficult for Audubon to discover the habits of many of North America's animals?
  • What details does Audubon record in his pictures of birds that show how the birds eat, live, or behave?
  • Here's a picture Audubon painted of the American Red Fox. What details do you notice about the fox's appearance? What details did Audubon put in the picture so that you can estimate the fox's size, eating habits, and ability to defend itself?

John Muir

In contrast, the explorer John Muir not only recognized the beauty of the wilderness, but, like Henry David Thoreau, felt that mankind needed the wilderness as a source of spiritual renewal. It is largely to Muir that we owe the idea of the National Park system and the creation of Yosemite National Park. Muir was an enthusiastic conservationist who was able to communicate his concerns and dreams to those around him, and eventually founded the Sierra Club.

Read about John Muir's life at the Sierra Club site, and the first entry [Chapter 1, Part 1] in Muir's diary on his summer journey into the Sierra Nevada Mountains of California.

  • What kinds of information is Muir interested in recording?
  • What does he notice about the geology of the country through which he is passing?
  • What kinds of detail does he record about the flight of a flock of birds?
  • What kinds of detail does he record about trees?

Muir's ideas were in marked contrast to those of conservationists like Gifford Pinchot, who believed that natural areas should be maintained to ensure a steady supply of their resources (such as lumber) for posterity. Both Pinchot and Muir opposed the unregulated use of wilderness resources without any thought for their restoration or the needs of future generations. But neither realized how complex the interrelationship of life on the planet could become....or that efforts to control one small area of nature could devastate others.

Rachel Carson

During the fourth decade of this century, the entire world suffered economic upheaval and famine. In the United States, the Great Depression was fueled in part by the dust storms in the midwest, which destroyed crops and removed topsoil from America's richest farmland. After the climate returned to something approaching normal, and the nation had survived war on two fronts, American farmers worked hard to restore their farms and the country to prosperity. The new techniques they used to increase crop yield included spraying plants with DDT (fresh from its war use of ridding soldiers of lice) to kill insect pests. Often, spraying was done by low-flying planes, and the poison fell not only on the plants, but on the ground, surrounding vegetation, all insects (not just the pests) and animals living in the area, and found its way into the water supply.

Rachel Carson was among those to voice her concern that widespread use of insecticides killed birds and bees as well as lice and mosquitoes--and that perhaps killing off all the mosquitoes was not such a good idea. S Her book, Silent Spring, published in 1962, forced the nation to reconsider its policies.

Read the biography of Rachel Carson at her Homestead site. Then read this article about the background and reception of Carson's Silent Spring.
  • What kinds of chemical poisoning does Carson cite in her book?
  • What "campaigns" to rid the country of one pest caused harm to other animals and backfired entirely?
  • How does Carson substantiate her claims?
  • Why does she believe that DDT is such a major problem?
  • What counter-arguments to Carson's claims did her opponents offer?
  • Why can small amounts of a chemical which has previously been useful suddenly become disastrous?

Carson's book represents a new attitude toward nature and man in it. She viewed humans as but one part of the web of life which related all living organisms, perhaps with no more right to be on the planet than ants or Douglas fir trees, but certainly--because of their minds and abilities, with the responsibility for choosing their activities carefully.

Study/Discussion Questions:

Further Study/On Your Own