The world of self-making by Jean-Baptiste Lamarck

The French naturalist Jean-Baptiste Lamarck was 65 years old when his great treatise on the transformation of life was published. With Zoological philosophy (1809), translated a century later by Zoological philosophyLamarck intended to establish an entirely new science, based on the idea that all living things are constantly transforming, from the smallest microbes to the most complex mammals, acquiring new forms and new abilities. It is not the bodily structures of organisms that determine their way of life, Lamarck said, but quite the opposite: their ways of life, in response to their circumstances, gave rise to changing bodily forms. “Can there be in natural history a more important consideration,” he asked, “or one which deserves greater attention than that which I have just presented? (My translation.)

But if you’ve heard of Lamarck, it’s probably how wrong he was about one particular animal, the giraffe, and how this giraffe fiasco embodies his mistake about the giraffe. All. Lamarck suggested that by stretching to reach the leaves on the high branches of trees, giraffes slightly elongated their necks, creating tiny changes that were then passed on to their offspring, accumulating over many generations to produce the long necks we see today. At the turn of 20th century, Lamarck’s idea of ​​the giraffe became a laughing stock when biologists flatly rejected the idea that bodily changes experienced during an individual lifetime could be inherited by the next generation.

It’s not just his ideas about long-necked mammals that have come under attack. Lamarck’s interest in giraffes was only a passing mention amid his voluminous writings, which expounded a revolutionary and founding theory: organisms, he asserted, transform themselves and, in doing so, they remake the world. This idea has been scorned for more than two centuries.

Although Lamarck is often overlooked, his science was fundamental to modern biology and inspired the theory of evolution that Charles Darwin later developed. Darwin followed Lamarck in believing in the power of living beings to transform themselves and their environment. But most people are unaware of Lamarck’s influence on Darwin because, at the turn of the century, 20th century, Darwin’s followers expunged all traces of Lamarckism from their neo-Darwinist version of evolution, making living things subject to random variation and external forces. For neo-Darwinists, living beings played no direct role in the evolutionary process. Evolution occurred through random genetic variation and external environmental pressures. To Darwin’s followers, organisms were just as passive as to creationists, who saw them as products of divine will.

Throughout the history of modern biology, the most influential figures in science and politics have ridiculed and suppressed Lamarck’s radical idea that organisms have agency in the evolutionary process. In today’s mainstream biology, a neo-Darwinian view of living beings as passive still largely dominates, although research in several fields challenges its reign.

This is the story of how Lamarck’s radical idea was rejected by mainstream science and why it was neglected for so long. It is also the story of a surprising reversal: in recent decades, some biologists have begun to return to the Lamarckian vision of life.

WAlthough many people think of giraffes when they hear Lamarck’s name, few know that he invented the word “biology” in 1802. He needed a name for a new science that he believed should exist: a science of all living things, and only living things. At the time, no such area existed. There were broader sciences, like natural history, that included inanimate things like rocks, rivers, and mountains; and there were more restricted sciences, such as botany or zoology, which covered subsets of the living world. But Lamarck thought that there should be a science of life. At the heart of his new science, he developed the first theory of what we today call “evolution,” although he did not call it that. He simply spoke of “change”.

Lamarck lived and worked at the Jardin des Plantes in Paris from 1788 until his death, at the age of 85, in 1829. His life was tumultuous, to say the least. He lived through the French Revolution, then under Napoleon, then under the Bourbon Restoration. He survived the Reign of Terror, the devastating contempt of Napoleon and his circle of scientific advisors, and the return of the monarchy; he also outlived three wives and four of his eight children. During the last decade of his life he was blind and frail but he continued to work with the help of his daughter Rosalie. By the end of his long career, he had identified and named more than 6,000 species and taught a legendary course at the Jardin des Plantes for more than two decades, attracting students from around the world. The course became so famous that even fictional characters took part, such as the young Amaury, hero of Sainte-Beuve’s autobiographical novel. Volupté: The Sensual Man (1834).

By daring to usurp God’s monopoly on Creation and reallocate it to mortal beings, Lamarck provoked the anger of the powerful. He wrote that life arose through spontaneous generation, caused by natural forces such as electricity and heat acting on inanimate matter. This led to the emergence of the simplest organisms: single-celled protozoa and algae. From there, there is an intrinsic property of living matter, a tendency towards complexity, which Lamarck calls “the power of life”. As organisms became more complex, another cause of transformation came into play: their responsiveness to the environment. In the simplest beings, this reactivity was rudimentary – an irritability or sensitivity and a reflexive reaction. But in birds and mammals, Lamarck argues, this rises to the level of “acts of will,” through which creatures can form “habits” and “ways of life” in response to their circumstances. Through these behaviors, they directed their internal fluids to the limbs and organs they used most. (Darwin would later propose a similar idea. In 1868, he suggested that certain parts of the body shed inheritance particles, called “gemmules,” which were changed by an animal’s behavior and could pass those changes on to its offspring.)

He imagined that the simplest animals could reveal to him the foundations of animal life.

Not only did living beings create and transform themselves, according to Lamarck’s view of things, but they also created and remade the inanimate world. Plants played the main role in this process, he believed, because they could invent themselves from sunlight, air and water alone. He described experiments to confirm this miraculous ability. For example, dig a hollow in the side of a turnip and hang the vegetable from a window by its root, Houdini style: nothing more! Keep the trough filled with water and you will see the turnip grow into a full flowering plant. He created himself literally from nothing. Plants, by bringing together the primitive elements into combinations, initiated the cosmic relay chain, and then passed their work on to animals. By eating, digesting, and engaging in their other functions and behaviors, animals produced more elaborate compounds and thus shared with plants the defining capacity of all living things to build, compose, and create.

After beginning his career in botany, Lamarck was forced, in 1793, to turn, reluctantly, to zoology. We are in the middle of the Revolution, at the time of transition when the main botanical garden of Paris – the Jardin du Roi – becomes the Republican Garden of Plants under the aegis of a new National Museum of Natural History. The committee responsible for this transformation did not award Lamarck a chair of botany as he wished, but rather the humblest chair of zoology: the chair of insects and worms. He would later tell his students that he was initially disappointed: if he couldn’t continue studying botany, then why not charismatic megafauna, like lions? But then he had two hopeful thoughts. First, the creatures assigned to him made up nine-tenths of the animal world, so he had not been relegated to an unimportant corner of zoology. And second, he imagined that the simplest animals could reveal to him the foundations of animal life. Gazing at his insects and worms with this faint glimmer of hope, he created a new taxonomic category, “invertebrates,” and set about studying it.

Invertebrates, he told his students in 1800, “lead us imperceptibly towards the inconceivable limit of animalization”, towards those beings “barely endowed with animality” with whom “nature perhaps began”. For Lamarck, this essence of animal life was the power of generation and regeneration: the capacity to produce living matter, including new bodily tissues and new organisms. The simplest animals possessed the most widespread generative faculties. For example, the Genevan naturalist Abraham Trembley had shown that if polyps (freshwater hydras) were cut into several pieces, they regenerated an entire animal from each part. Other invertebrates also possessed incredible powers of generation. Insects could metamorphose. Crustaceans could have new legs. Starfish, new rays. Snails, a new head. Invertebrates far outnumber vertebrates, Lamarck explains, thanks to this generative capacity. Their number is unknowably vast because of the “infinite smallness” of the smallest of them. These animals…