When discussing evolution, one of the first names that comes to mind is Charles Darwin (Castillero Mimenza, 2018). However, Darwin was not the only significant figure in this field; other thinkers offered different perspectives on the evolution of species, and some even influenced Darwin’s work. Among these authors, one of the most notable is Jean-Baptiste Lamarck (1744–1829). Although Lamarck’s theories have lost popularity over time and have been replaced by more scientifically supported approaches, his initial contributions were crucial to the development of evolutionary thought. Lamarck was one of the first to separate the development of species from religious faith and is also recognized as the father of the term "biology" as we understand it today. According to Castillero Mimenza (2018), his evolutionary theory, although now obsolete, was one of the first to be truly coherent and systematic in its structure.
Biography
Jean-Baptiste Pierre Antoine de Monet, known as Lamarck, was born on August 1, 1744, in Bazentin, a small town in the Picardy region of Somme, France (Castillero Mimenza, 2018). He was the eleventh child of Philippe Jacques de Monet de La Marck and Marie-Françoise de Fontaines de Chuignolles, who came from a noble family dedicated to the military. During his childhood, his father enrolled him in a Jesuit seminary, hoping that Lamarck would pursue an ecclesiastical career. According to Castillero Mimenza (2018), during his time at the seminary, Lamarck received general training in various disciplines within the religious field, including philosophy and theology.
At the age of 15, due to his father’s death in 1759, he left the seminary and decided to join the army (Castillero Mimenza, 2018). At 17, in 1761, he bought a horse and enlisted as an officer. He quickly rose in rank and participated in the Seven Years' War. However, his military career was short-lived, as at the age of 20, he suffered a severe neck injury that caused scrofula, an infectious disease affecting the lymph nodes, forcing him to retire from the army. After his retirement, he moved to Paris, where he initially lived on a pension and inherited part of his father’s fortune. He attempted to dedicate himself to music but soon abandoned this pursuit to study medicine, devoting four years to botany. During this period of his life, according to Castillero Mimenza (2018), his interest in botany grew so strong that he decided to fully commit to the natural sciences, where he would find his true field of work.
Through his tireless efforts, he gained recognition, and in 1779, he published his first major book, "Flore François", a botanical classification system of French species, in which he introduced a dichotomous method for describing plants (Castillero Mimenza, 2018). This publication allowed him to gain scientific notoriety, and soon after, he was named a member of the Academy of Sciences. In 1780, he was contacted by Georges-Louis Leclerc, Count of Buffon, to lead a mission in Europe to expand the botanical collection of the Jardin du Roi. According to Castillero Mimenza (2018), this mission was successful, further solidifying his reputation as a botanist.
Shortly after Buffon's death in 1788, his successor, Flahault de la Billarderie, created a position for Lamarck as the "King’s Botanist and Keeper of the King’s Herbarium" (Burkhardt, 2024). From then on, he carried out his duties at the royal garden, known as the Jardin du Roi, until 1793 (Castillero Mimenza, 2018). During that period, he married Marie Annie Rosalie Delaforte, with whom he had five children, but she passed away in 1792. Following the French Revolution, and thanks to his influence, the garden was transformed into the National Museum of Natural History, where Jean-Baptiste Lamarck was appointed director of the department of lower animals, overseeing the study of insects and other invertebrates. According to Castillero Mimenza (2018), he coined the term "invertebrates" and developed the primary subdivisions of these animals, as well as introducing the concept of "biology" as the science of living organisms.
In 1793, he married for the second time, to Victoire Charlotte Reverdy, with whom he had two more children, though she passed away in 1797 (Castillero Mimenza, 2018). A year later, he married for the third time, to Julie Mallet. During this period, he began teaching and wrote his most renowned work, "Natural History of Invertebrates", which was published between 1815 and 1822. During these studies, his theory of evolution also began to take shape. Additionally, in meteorology, he was a pioneer in weather prediction through probabilistic methods, suggesting that atmospheric behavior could be forecasted by understanding the causes of atmospheric alterations, such as the influence of the Sun, the Moon, and Earth's rotation. Despite his efforts, Castillero Mimenza (2018) indicates that Lamarck published several meteorological yearbooks that contained errors, leading to a decline in his prestige.
Initially, Lamarck maintained that living beings did not undergo changes, but over time and through his research, he concluded that an evolutionary process existed (Castillero Mimenza, 2018). These ideas were presented in his work "Zoological Philosophy" in 1809, considered the first theoretical formulation of evolution, in which he proposed two fundamental laws: the first stated that the size and strength of organs change during an animal’s lifetime depending on their use, and the second asserted that these modifications are transmitted to subsequent generations (Castillero Mimenza, 2018; Ashworth, 2022). Lamarck concluded that species modify over time through the inheritance of acquired characteristics (Ashworth, 2022). Although his theory was rejected by figures such as Napoleon Bonaparte and criticized by scientists like Lavoisier and Georges Cuvier, who considered it unscientific, Castillero Mimenza (2018) notes that his work marked a milestone in the scientific debate of the time.
In his later years, Lamarck’s health deteriorated progressively, and his relationships with various authors became increasingly strained, negatively impacting his reputation (Castillero Mimenza, 2018). One of his most notable disputes was with Lavoisier, whose theory on fluid dynamics was criticized by Lamarck for lacking scientific rigor. Lamarck’s work was dismissed as lacking objectivity, and his arguments were deemed overvalued, leading to a loss of credibility. Another significant conflict occurred with biologist Georges Cuvier, whose more empirical and experimental approach contradicted Lamarck’s theories. Cuvier even labeled Lamarck’s ideas as erroneous, deepening their rivalry. Over time, according to Castillero Mimenza (2018), Lamarck’s contributions to evolution became increasingly discredited, further deteriorating his prestige.
In 1819, he lost his sight, forcing him to dictate some of his works to his daughters (Castillero Mimenza, 2018). During this same period, he suffered the loss of his third wife, Julie Mallet. The combination of his deteriorating health, his declining reputation, and his growing poverty led him into deep depression, and he spent his final years cared for by his daughters, receiving little public recognition. Lamarck passed away on December 18, 1829, at the age of 85 in Paris. Although his theory of evolution was eventually supplanted by Darwin’s, and despite being largely ignored in his later years, Lamarck’s ideas have been recognized as a significant advancement in the science of his time. According to Castillero Mimenza (2018), despite not achieving the fame he deserved during his lifetime, he is credited with crucial concepts such as invertebrates and biology, along with making important contributions to both botany and zoology.
Evolution and Transformation of Species: Lamarck’s Theory
Lamarck’s Theory, proposed in 1809, marked the formal beginning of studies on biological evolution (Salcedo, 2024). As a precursor to Darwin’s theory of evolution, it introduced the idea that current species evolved from simpler life forms and have undergone transformations over time. According to Salcedo (2024), Lamarck presented his perspective in the book "Philosophie Zoologique", where he proposed a mechanism to explain the evolutionary transition between species, based on two principles: the law of use and disuse, and the inheritance of acquired traits.
Lamarck argued that organisms could develop new physical characteristics by repeatedly using certain parts of their body, and these modifications were then passed on to their offspring, contributing to the evolution of the species (Salcedo, 2024). The most illustrative example of this theory is the giraffe’s neck. According to Lamarck, ancestral giraffes, faced with the need to reach leaves on tall trees, would have progressively stretched their necks, eventually transmitting this trait to the rest of the species. In line with Salcedo (2024), this interpretation provided a model for understanding biological change, further supported by the discovery of fossils showing extinct species with anatomical structures similar to those of some current species.
Despite the relevance of this theory in its time, Lamarck’s Theory has faced significant criticism, as it lacked solid scientific evidence to support its claims about the transmission of acquired traits (Salcedo, 2024). However, his proposal was essential in establishing a foundation for discussion and work in later evolutionary theories, including Darwin’s theory of natural selection, developed during the second half of the 19th century. The main difference between both theories lies in the evolutionary mechanism each postulates. Salcedo (2024) mentions that while Lamarck suggested that acquired traits during an organism's lifetime could be inherited, Darwin proposed that chance and natural selection guided the evolution of species, ensuring the survival of the fittest organisms in their environment.
Lamarck’s Theory: Rejection, Re-evaluation, and Advances in Epigenetics
In the 19th century, Lamarck’s theory of evolution faced notable rejection due to its opposition to the theories of fixism and catastrophism, which were highly regarded and strongly defended by the scientific community of the time (Salcedo, 2024). These theories, promoted by influential figures like George Cuvier, proposed that species were essentially immutable, except for sudden, violent, and rare changes. Cuvier, with great respect in the scientific community, supported these ideas, making it difficult for Lamarck’s evolutionary ideas to gain acceptance. As a result, according to Salcedo (2024), most naturalists of the time considered Lamarck’s theory to lack sufficient evidence to explain the evolutionary process of species.
Today, however, scientific evidence suggests that several aspects of Lamarck’s theory are incorrect (Salcedo, 2024). Advances in genetics have shown that the inheritance of acquired traits is not possible, as only changes affecting the genetic material of gametes can be transmitted. In other words, for a characteristic to be inherited, chemical modifications must occur in the DNA. Since the first decade of the 21st century, however, the field of epigenetics has started reconsidering concepts similar to those of Lamarck. In particular, according to Salcedo (2024), some epigenetic discoveries have suggested that the environment can influence genetic expression in a way that could, in certain contexts, affect subsequent generations, partially reviving Lamarckian ideas that acquired traits may, under specific circumstances, have hereditary influence.
Lamarck’s Legacy in Evolutionary Theory
Although current research has demonstrated that evolution does not strictly follow the theories proposed by Lamarck, his contributions remain fundamental to the development of scientific knowledge in biology (Salcedo, 2024). His ideas, formulated in an adverse context, emerged at a time when evolutionary concepts were just beginning to be explored through the scientific method. This pioneering approach made his theories, in many ways, more revolutionary than those of Darwin. According to Salcedo (2024), Lamarck was the first to propose a complete theory of biological evolution, daring to challenge the fixism defended by Georges Cuvier, who maintained that living organisms were immutable and emerged spontaneously and definitively, sometimes under divine origin.
Lamarck’s transformational vision completely broke with the paradigm imposed by fixism, paving the way for a new way of understanding the development and adaptation of living beings (Salcedo, 2024). In Lamarck’s time, the natural sciences were limited to describing the characteristics of organisms without delving into their origin or transformation. However, in accordance with Salcedo (2024), his work Philosophie Zoologique marked a turning point by introducing a dynamic perspective of living beings, laying the groundwork for what is now known as modern biology.
References
Ashworth, G. B. (2022, marzo 16). Jean-Baptiste Lamarck. The Linda Hall Library. https://www.lindahall.org/about/news/scientist-of-the-day/jean-baptiste-lamarck/
Burkhardt, R. W. (2024). Jean - Baptiste Lamarck. En Encyclopedia Britannica. https://www.britannica.com/biography/Jean-Baptiste-Lamarck
Castillero Mimenza, O. (2018, noviembre 2). Jean-Baptiste Lamarck: Biografía de Este Naturalista Francés. Psicología y Mente. https://psicologiaymente.com/biografias/jean-baptiste-lamarck
Salcedo, M. (2024). Teoría de Lamarck. Enciclopedia Concepto. https://concepto.de/teoria-de-lamarck/
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