The acceptance of biological evolution
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James Ussher |
The traditional Judeo-Christian version of creationism
This belief that the earth and life on it are only about 6000 years old fit neatly with the then prevalent theory of the "Great Chain of Being." This held that God created an infinite and continuous series of life forms, each one grading into the next, from simplest to most complex, and that all organisms, including humans, were created in their present form relatively recently and that they have remained unchanged since then. Given these strongly held beliefs, it is not surprising that 17th and 18th century European biology consisted mainly of the description of plants and animals as they are with virtually no attempt to explain how they got to be that way.
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Carolus Linnaeus 1707-1778 |
The leading biological scientist of the mid 18th century was the Swedish botanist Karl von Linn� (Carolus Linnaeus
Despite his limiting research bias, Linnaeus was a first class scientist. His most important contribution to science was his logical classification system for all living things which he proposed in his book Systema Naturae, first published in 1735. In this and subsequent works, he described plants and animals on the basis of physical appearance and method of reproduction. He classified them relative
to each other according to the degree of their similarities. He used a binomial nomenclature
species | species | species | species |
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John Ray |
The concept of genus and species was actually developed in the late 1600's by John Ray, an English naturalist and ordained minister. However, it was Linnaeus who used this system to name us Homo sapiens
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Comte de Buffon 1707-1788 |
Late in the 18th century, a small number of European scientists began to quietly suggest that life forms are not fixed. The wealthy French mathematician and naturalist, George Louis Leclerc, Comte de Buffon
Buffon was an early advocate of the Linnaean classification system. He was also a quiet pioneer in asserting that species can change over generations. However, he publicly rejected the idea that species could evolve into other species. One of his most significant contributions to the biological sciences was his insistence that natural phenomena must be explained by natural laws rather than theological doctrine.
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Erasmus Darwin |
Another late 18th century closet-evolutionist was Erasmus Darwin
The first evolutionist who confidently and very publicly stated his ideas about the processes leading to biological change was a French prot�g� of the Comte de Buffon. He was Jean-Baptiste Chevalier de Lamarck
Lamarck believed that microscopic organisms appear spontaneously from inanimate materials and then transmute, or evolve, gradually and progressively into more complex forms through a constant striving for perfection. The ultimate product of this goal-oriented evolution was thought by Lamarck to be humans. He believed that evolution was mostly due to the inheritance of acquired characteristics as creatures adapted to their environments. That is, he believed that evolution occurs when an organism uses a body part in such a way that it is altered during its lifetime and this change is then inherited by its offspring. For example, Lamarck thought that giraffes evolved their long necks by each generation stretching further to get leaves in trees and that this change in body shape was then inherited. Likewise, he believed that wading birds, such as herons and egrets, evolved their long legs by stretching them to remain dry. Lamarck also believed that creatures could develop new organs or change the structure and function of old ones as a result of their use or disuse.
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Lamarck's incorrect idea of the cause of evolution | Jean-Baptiste Lamarck 1744-1829 |
Lamarck did not invent the idea of inheritance of acquired characteristics but stated it clearly and publicly in an 1809 publication entitled Philosophie Zoologique. It was relatively easy for the French scientist, George Cuvier
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George Cuvier 1769-1832 |
While Lamarck's explanation of evolution was incorrect, it is unfair to label him a bad scientist. In fact, he was at the cutting edge of biological research for his time. He and George Cuvier were largely responsible for making biology a distinct branch of science.
Despite his criticism of Lamarck, Cuvier did not reject the idea that there had been earlier life forms. In fact, he was the first scientist to document extinctions of ancient animals and was an internationally respected expert on dinosaurs. However, he rejected the idea that their existence implied that evolution had occurred--he dogmatically maintained the "fixity" of species.
Cuvier advocated the theory of catastrophism
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Charles Lyell 1797-1875 |
A careful examination of European geological deposits in the early 19th century led the English lawyer and geologist, Charles Lyell
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James Hutton |
Lyell provided conclusive evidence for the theory of uniformitarianism
This revolutionary idea was instrumental in leading Charles Darwin to his understanding of biological evolution in the 1830's. However, it was not until the late 19th century that most educated people in the Western world finally rejected the theory of catastrophism in favor of uniformitarianism.
Today, we know that our planet has been shaped by occasional catastrophic events, such as bombardment of large meteors, in addition to the comparatively slower natural processes suggested by uniformitarianism. All of these events have potentially affected the rate and direction of biological evolution.
NOTE: While George Cuvier and Charles Lyell strongly disagreed about how the earth got to be the way it is today, they both rejected the idea of biological evolution. However, neither man accepted a traditional Biblical account of creation and a young earth. Cuvier did not live long enough to learn about Charles Darwin's proof of evolution, but Lyell did. He came to
accept this proof in the early 1860's along with most leading scientists of that time. Lyell also became a friend of Charles Darwin.
Copyright � 1998-2012 by Dennis O'Neil. All rights reserved.
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