The Treatment of Geological Time the History of Life on Earth: In High School Biology Textbooks‪.‬

The concept of evolution is fundamental to the study of modern biology. It is a key element of the National Science Education Standards (National Research Council, 199(5) and is recognized as an essential component of the curriculum in position statements of the National Science Teachers Association and the National Association of Biology teachers (see National Academy of Sciences, 1998). Since all of the definitions of evolution (e.g, "organic change over tune' or "descent with modification") imply a temporal element, the presentation of evolution in the biology curriculum should include some sense of the timespan over which evolutionary events have occurred as well as an overview of the life forms at various points tit geological time. fit addition, the evidence that supports these claims and the reasoning processes that scientists use to study historical events should he a standard element in any presentation of the principles of scientific inquiry. In spite of the importance of geological time in evolutionary biology, misconceptions about historical events in the history of life on Earth are common. For example, a recent survey by the National Science Foundation found that almost 50% of the general public believes that humans and dinosaurs coexisted (National Science Board, 2000). Misconceptions about geological time are also common in biology teachers. A survey of high school biology teachers the Indiana reported that 12.5% of respondents agreed or strongly agreed with the statement, "The age of the Earth is less than 20,000 years," while 15% accepted the statement, "With few exceptions organisms on Earth carne into being at about the same time (Rutledge & Warden, 2000). The same two statements received higher levels of support among high school biology teachers in texas (Shankar Skoog, 1993). Surveys and opinion polls like these suggest that ideas about geological tittle that tile scientific community rejected long ago are durable elements of the public view of evolutionary biology.