Lamarcks Theory of Evolution and its Legacy

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"Lamarcks Theory of Evolution and its Legacy"
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In the 1800s, several factors led to critical thinking and the idea of evolution as opposed to Gods creation. These included geological expeditions, discovery of the fossil record and the epic voyage of Charles Darwin, writer of the "Origin of the Species" in 1895 and his controversial theory of evolution.

Predating these events, Jean-Baptiste Lamarck, French soldier, naturalist, and academic, wrote a book published in 1809, "Philosophie Zoologique" in which he promulgated the inheritance of acquired characteristics.

Like other early scientists, he noticed that species change, a theory contrary to the teaching of the church, a dangerous place to be in the times. Early writers including Aristotle suggested that some species might give rise to new species. Some ancient writing speaks of the transmutation of species, but did not consider heredity.

Lamarck based his theory on two generalities. Individuals lose characteristics they do not use, a use it or lose it type of saying that we hear often today. He thought that people inherited the acquired traits of their parents. For instance, if the father is muscular because of a strenuous life style, the sons will also be muscular.

Another example he cited is that of giraffes stretching their necks to reach higher trees. The stretching over time makes their necks longer, a trait passed on to their offspring.

He called these examples of soft inheritance and used these theories to develop two laws.

The first is that using an organ makes it stronger and disuse of an organ makes it weaker, the "use it or lose it" idea so popular today. New born individuals inherit these tendencies.

His second law states that species follow a drive to perfection. As the environment changes, the organs change to meet the prevailing conditions. This leads to the gradual transmutation of the species. Transmutation is the changing of one species into another, for instance monkeys to humans.

Later observation shows the fallacy of these observations. Children do not present with the acquired characteristics of their parents, but genes govern their innate traits such as the tendency to develop muscles or become writers.

He argued that instinct in animals evidences hereditary knowledge. We hear about dogs that travel hundreds of miles in search of their families when separated from them. Birds know how to migrate. In an effort to save the endangered cranes, the birds had to be taught the route by following a homemade airplane to learn the route that normally the birds parents would teach them.

Perhaps in deference to established principle set by Aristotle he also espoused the idea of spontaneous generation of life from non-living material or objects. Aristotle believed that crabs generate from slime, and the darkness of the uterus generates a baby. In his most famous example, he thought eels did not reproduce because they had neither milt nor spawn, and had no eggs or birth tubes. He could not have known that eels develop these parts when they go into the sea to spawn.

Mice do not arise from dirty underwear even though they might like to live in it. Worms and frogs do not jump up from dust or rotten food. It was disproved over a hundred years ago.

Lamarck was a man born too soon. He would have greatly benefited by the knowledge of genes and chromosomes, which was unknown until after Lamarck's death. He died 30 years before the publication of Charles Darwin's "Origin of Species." He left a legacy of creative thinking and perhaps the first thoughts on evolution.

More about this author: JoAnne Windsinger

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