Lamarcks Theory of Evolution and its Legacy

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"Lamarcks Theory of Evolution and its Legacy"
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At a time when science was still the realm of gentleman and Aristotle was still revered as the greatest of all scientists, there lived a man named Lamarck (not his real name, but the one under which he published) who in many ways was a product of his time.

He was an scientist of the old school who believed in Alchemy. I don't know if he ever tried to turn lead into gold but he set great store by the idea that everything depended on the ancient elements. He had no trust in new advances in science such as the modern chemistry pioneered by his countryman Lavoisier. In fact he despised Lavoisier's ideas.

So it is surprising that this man who actually in many ways was an anti-scientist a throwback to more primitive beliefs who was unable to keep up with the greatest discoveries of his day was actually able to advance a theory, or if not advance at least formulate a theory, that although later proven to be utterly wrong paved the way for another theory that would later vastly influence the course of modern science.

Lamarck was a believer in spontaneous generation, just like many of his contemporaries. He believed that the simplest lifeforms such as maggots and flies came into existence out of nothing. Although Francisco Redi had already done experiments in 1668 that seemed to give the death-blow to spontaneous generation at the same time advances in the microscope by Van Leeuwenhoek in the late 1600's and the subsequent discovery of micro organisms gave new credence to this old theory.

So along comes Lamarck in the mid 1700's and he uses spontaneous generation as one of the cornerstones in his theory of evolution. Of course when in the 1800's Pasteur proves spontaneous generation to be wrong once and for all that is the death-knell for Lamarck and his theories and he is never again taken seriously.

So what was it Lamarck proposed? Well he proposed a fully fledged theory of evolution. His famous countryman Cuvier who was one of the birth fathers of modern palaeontology had already hinted at the possibility of evolution. But Lamarck took a more courageous stance not only hinting at the possibility but working out the details.

Lamarck saw evolution as an ongoing process with species constantly moving up the ladder of evolution to greater complexity. As species moved up the evolutionary ladder they left room for new lower lifeforms to take their place through spontaneous generation. The process Lamarck proposed for this increase in complexity was to say the least vague and totally incomprehensible to modern ears as it rested entirely on the now disproved notions of alchemy.

Here is a quote to prove my point:

The rapid motion of fluids will etch canals between delicate tissues. Soon their flow will begin to vary, leading to the emergence of distinct organs. The fluids themselves, now more elaborate, will become more complex, engendering a greater variety of secretions and substances composing the organs.

- Histoire naturelle des animaux sans vertebres, 1815.

It makes no sense right? Had Lamarck stopped here he might well have deserved the relative obscurity that now surrounds his memory. However besides this move towards complexity he also developed a theory about the adaptation of species. One that comes a lot closer to our modern understanding of evolution.

Lamarck developed two laws about adaptation.

The first law said that if during their lifetimes animals used certain organs more those would develop more (like strengthening a muscle) and that if organs were not used they atrophied (like your legs if you never walk).

The second law said that these traits could then be inherited.

His most famous example involves giraffes, stating that giraffes stretching their necks to reach high leaves actually caused their necks to lengthen during their lifetime and this trait was passed on to the next generation.

What was remarkable about Lamarck's theory was that he surmised that changes in the animal's environment would precipitate these changes to the animal's organs which is exactly what Darwin proposed. The difference in the theories rest merely in the way the changes are passed on.

So here we see Lamarck's legacy. For not only did he stumble on vital components of the process he also inspired Darwin and his contemporaries to find the real truth.

But Lamarck never got and is still not getting the credit he deserved. He died poor and in obscurity and his theories are used as examples of an old outdated way of thinking.

But in future Lamarck's theory might turn out to be greater than we ever reckoned with. Because already Darwin's theory of evolution seems to be at a loss to explain some of the more complex adaptations down the chain of evolution that we are now seeing. Maybe evolution is more complex than we think and maybe more processes are at work than we have accounted for.

Can changes in the environment not only give an advantage to those with better genes but also help give feedback to our genetic code, altering our DNA as we live? This has long been considered impossible by science, but who knows. Maybe we know less than we think we know and Lamarck might be having the last laugh.




More about this author: Stefan Joosten

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