Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biological evolution occurred and proceeded in accordance with natural laws, though the mechanism he suggested has been refuted at large.
Lamarck fought in the Seven Years' War against Prussia, and was awarded a commission for bravery on the battlefield. Posted to Monaco, Lamarck became interested in natural history and resolved to study medicine. He retired from the army after being injured in 1766, and returned to his medical studies. In an 1802 publication, he became one of the first to use the term "biology" in its modern sense. Lamarck continued his work as a premier authority on invertebrate zoology. He is remembered, at least in malacology, as a taxonomist of considerable stature.
The modern era generally remembers Lamarck for a theory of inheritance of acquired characteristics, called Lamarckism (inaccurately named after him), soft inheritance, or use/disuse theory, which he described in his 1809 Philosophie zoologique. Though, the idea of soft inheritance antedates him, and while it was a small element of his theory of evolution, in his time it was accepted by many natural historians. Lamarck's idea of use/disuse later aligned with Darwin's idea of natural selection and is believed to in part have inspired Darwin, who ended up contradicting Lamarckism. Lamarck's contribution to evolutionary theory consisted of the first truly cohesive theory of biological evolution, in which an alchemical complexifying force drove organisms up a ladder of complexity, and a second environmental force adapted them to local environments through use and disuse of characteristics, differentiating them from other organisms. Scientists have debated whether advances in the field of transgenerational epigenetics mean that Lamarck was to an extent correct, or not.
Biography
Jean-Baptiste Lamarck was born in Bazentin, Picardy, northern France, Georges-Louis Leclerc, Comte de Buffon, one of the top French scientists of the day, mentored Lamarck, and helped him gain membership to the French Academy of Sciences in 1779 and a commission as a royal botanist in 1781, in which he traveled to foreign botanical gardens and museums. Lamarck's first son, André, was born on 22 April 1781, and he made his colleague André Thouin the child's godfather.
In his two years of travel, Lamarck collected rare plants that were not available in the Royal Garden, and also other objects of natural history, such as minerals and ores, that were not found in French museums. On 7 January 1786, his second son, Antoine, was born, and Lamarck chose Antoine Laurent de Jussieu, Bernard de Jussieu's nephew, as the boy's godfather. On 21 April the following year, Charles René, Lamarck's third son, was born. René Louiche Desfontaines, a professor of botany at the Royal Garden, was the boy's godfather, and Lamarck's elder sister, Marie Charlotte Pelagie De Monet, was the godmother. In 1788, Buffon's successor at the position of Intendant of the Royal Garden, Charles-Claude Flahaut de la Billaderie, comte d'Angiviller, created a position for Lamarck, with a yearly salary of 1,000 francs, as the keeper of the herbarium of the Royal Garden. Lamarck had worked as the keeper of the herbarium for five years before he was appointed curator and professor of invertebrate zoology at the Muséum national d'histoire naturelle in 1793. The following year, on 9 October, he married Charlotte Reverdy, who was 30 years his junior. On 26 September 1794 Lamarck was appointed to serve as secretary of the assembly of professors for the museum for a period of one year. In 1797, Charlotte died, and he married Julie Mallet the following year; she died in 1819.
In his first six years as professor, Lamarck published only one paper, in 1798, on the influence of the moon on the Earth's atmosphere. In Hydrogéologie, Lamarck advocated a steady-state geology based on a strict uniformitarianism. He argued that global currents tended to flow from east to west, and continents eroded on their eastern borders, with the material carried across to be deposited on the western borders. Thus, the Earth's continents marched steadily westward around the globe.
That year, he also published Recherches sur l'Organisation des Corps Vivants, in which he drew out his theory on evolution. He believed that all life was organized in a vertical chain, with gradation between the lowest forms and the highest forms of life, thus demonstrating a path to progressive developments in nature.
In his own work, Lamarck had favored the then-more traditional theory based on the classical four elements. During Lamarck's lifetime, he became controversial, attacking the more enlightened chemistry proposed by Lavoisier. He also came into conflict with the widely respected palaeontologist Georges Cuvier, who was not a supporter of evolution. According to Peter J. Bowler, Cuvier "ridiculed Lamarck's theory of transformation and defended the fixity of species." According to Martin J. S. Rudwick:
Lamarck gradually turned blind; he died in Paris on 18 December 1829. When he died, his family was so poor, they had to apply to the Academie for financial assistance. Lamarck was buried in a common grave of the Montparnasse cemetery for just five years, according to the grant obtained from relatives. Later, the body was dug up along with other remains and was lost. Lamarck's books and the contents of his home were sold at auction, and his body was buried in a temporary lime pit.
After his death, Cuvier used the form of a eulogy to denigrate Lamarck:
Lamarckian evolution
While he was working on Hydrogéologie (1802), Lamarck had the idea to apply the principle of erosion to biology. This led him to the basic principle of evolution, which saw the fluids in organs inheriting more complex forms and functions, thus passing on these traits to the organism's descendants. This was a reversal from Lamarck's previous view, published in his Memoirs of Physics and Natural History (1797), in which he briefly refers to the immutability of species.
Lamarck stressed two main themes in his biological work (neither of them to do with soft inheritance). The first was that the environment gives rise to changes in animals. He cited examples of blindness in moles, the presence of teeth in mammals and the absence of teeth in birds as evidence of this principle. The second principle was that life was structured in an orderly manner and that many different parts of all bodies make possible the organic movements of animals. Developments in epigenetics, the study of cellular and physiological traits that are heritable by daughter cells and not caused by changes in the DNA sequence, have caused debate about whether a "neolamarckist" view of inheritance could be correct: Lamarck was not in a position to give a molecular explanation for his theory. Eva Jablonka and Marion Lamb, for example, call themselves neolamarckists. Reviewing the evidence, David Haig argued that any such mechanisms must themselves have evolved through natural selection.
Darwin allowed a role for use and disuse as an evolutionary mechanism subsidiary to natural selection, most often in respect of disuse. He praised Lamarck for "the eminent service of arousing attention to the probability of all change in the organic... world, being the result of law, not miraculous interposition". Lamarckism is also occasionally used to describe quasi-evolutionary concepts in societal contexts, though not by Lamarck himself. For example, the memetic theory of cultural evolution is sometimes described as a form of Lamarckian inheritance of nongenetic traits.
Species and other taxa named by Lamarck
During his lifetime, Lamarck named a large number of species, many of which have become synonyms. The World Register of Marine Species gives no fewer than 1,634 records. The Indo-Pacific Molluscan Database gives 1,781 records. Among these are some well-known families such as the ark clams (Arcidae), the sea hares (Aplysiidae), and the cockles (Cardiidae). The International Plant Names Index gives 58 records, including a number of well-known genera such as the mosquito fern (Azolla).
Species named in his honour
The honeybee subspecies Apis mellifera lamarckii is named after Lamarck, as well as the bluefire jellyfish (Cyanea lamarckii). A number of plants have also been named after him, including Amelanchier lamarckii (juneberry), Digitalis lamarckii, the palm tree Dictyocaryum lamarckinum, and Aconitum lamarckii, as well as the grass genus Lamarckia.
The International Plant Names Index gives 116 records of plant species named after Lamarck.
Among the marine species, no fewer than 103 species or genera carry the epithet "lamarcki", "lamarckii" or "lamarckiana", but many have since become synonyms. Marine species with valid names include: