Georges LeClerc (1707-1788) proposed a mechanism for calculating the age of the Earth using molten spheres of iron and measuring cooling times, after which he proposed that the Earth was at least 75,000 years old and perhaps as old as three million years.

Some students may feel that we should not focus on the past, and that our thoughts should be trained on new knowledge and invention, rather than antiquated ideas. What these students do not understand is the importance of the old ideas in shaping our current understanding of the world around us, and that an outright dismissal of past theories simply because they have been rejected by new evidence may limit our understanding of current theories.

There is value of learning about hypotheses that were once espoused to explain an observed phenomenon, but that have now been long disproved and invalidated. Darwin‘s theory of natural selection as the mechanism for evolution is all too often taught in a vacuum in high school biology classrooms, as if this brilliant naturalist developed a groundbreaking theory on natural order which had never before been contemplated in any form. It is only by learning about the gradual development of evolutionary theory, and the role of some religious individuals in shaping this theory, that students may come to see the logic and power behind Darwin‘s relatively simple ideas.

Many of the contributions upon which Darwin built his ideas came from scientists who were staunch creationists themselves. These scientists believed that all organisms on Earth had been placed here through ―special creation,‖ by God, because there was little evidence at the time to support evolution. LeClerc also perceived that species were not fixed and could change over time; he even proposed that closely related species, such as the horse and donkey, had developed from a common ancestor and had been modified by different climactic conditions. Yet, LeClerc was a devout Christian creationist and devoted much of his writing to the debunking of evolutionary ideas. Despite their commitments to religion, LeClerc and Linnaeus both gave Darwin crucial raw material to work with—their ideas concerning the similarities between related species and possible connections with common ancestors cried out for a reasonable explanation.

For centuries before Darwin, data that challenged the biblical account of creation was surfacing in many fields of research. As explorers began to study the forces that shape the Earth, such as mountain building and volcanic eruptions, accounts from scripture and assertions that the Earth was very young began to be called into question. Uniformitarian geologists such as Charles Lyell felt that the only reason mountains and other features of the Earth‘s terrain had been built the way they had was because of long, gradual processes that shaped these structures. There was no way, he felt, that the Earth could be several thousand years old as asserted in the Bible. In addition, the discovery of new plants, animals, and fossils as explorers travelled to uncharted regions of the world aroused suspicion about the paucity of animal and plant ―kinds‖ in the Bible. Improvements in scientists‘ abilities to estimate the age of the Earth and the relative ages of fossils also pushed people to question old assumptions

1. Taking into account all that was argued by the author, the main idea of this passage is that:

A. religious scientists before Darwin greatly influenced his formation of the theory of natural selection.
B. similarities between species of plants and animals were too great to ignore as people attempted to explain relationships in nature.
C. Darwin relied on a great deal of information from those who lived before him as he formed his well-known conclusions about the mechanisms of evolution.
D. old ideas should not be dismissed simply because they are old and disproved.
E. There is no connection between old ideas and new ones




2. If the author were teaching a class on evolution in a university in the Unites States, the passage suggests that the class would spend a significant amount of time discussing:

A. the origins of Darwin‘s theory of natural selection.
B. details of Darwin‘s theory of natural selection.
C. the Biblical account of creation.
D. taxonomy and classification and their importance in Darwin‘s ideas.
E. the future of evolution



3. The author‘s discussion of Darwin‘s theory in paragraph 3 of the passage suggests that:

A. Darwin does not deserve the credit he is given for his ideas on evolutionary theory.
B. Darwin‘s theories should be presented in the context within which they were originally conceived.
C. Darwin‘s ideas would be properly devalued if people knew the religious background from which his ideas stemmed.
D. Darwin‘s ideas are simple enough that he didn‘t need much help in formulating them.
E. Darwin‘s ideas have no place in modern theories of evolution



4. According to the passage, the idea that mountains and other structures take a great deal of time to form was an idea championed by:

A. catastrophists.
B. Darwinists.
C. creationists.
D. uniformitarians.
E. modern scientists