[5] Lamarck developed a particular interest in botany, and later, after he published the three-volume work Flore françoise (1778), he gained membership of the French Academy of Sciences in 1779.

In 1801, he published Système des animaux sans vertèbres, a major work on the classification of invertebrates, a term which he coined.

However, the idea of soft inheritance long antedates him, formed only a small element of his theory of evolution, and was in his time accepted by many natural historians.

[11] Jean-Baptiste Lamarck was born in Bazentin, Picardy, northern France,[5] as the 11th child in an impoverished aristocratic family.

[5] After his father died in 1760, Lamarck bought himself a horse, and rode across the country to join the French army, which was in Germany at the time.

Lamarck showed great physical courage on the battlefield in the Seven Years' War with Prussia, and he was even nominated for the lieutenancy.

[5] Lamarck's company was left exposed to the direct artillery fire of their enemies, and was quickly reduced to just 14 men—with no officers.

When their colonel reached the remains of their company, this display of courage and loyalty impressed him so much that Lamarck was promoted to officer on the spot.

However, when one of his comrades playfully lifted him by the head, he sustained an inflammation in the lymphatic glands of the neck, and he was sent to Paris to receive treatment.

He was interested in botany, especially after his visits to the Jardin du Roi, and he became a student under Bernard de Jussieu, a notable French naturalist.

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.

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.

[16] 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.

[20] According to Peter J. Bowler, Cuvier "ridiculed Lamarck's theory of transformation and defended the fixity of species.

Lamarck was buried in a common grave of the Montparnasse cemetery for just five years, according to the grant obtained from relatives.

Lamarck's books and the contents of his home were sold at auction, and his body was buried in a temporary lime pit.

[12] 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.

He believed that these forces must be explained as a necessary consequence of basic physical principles, favoring a materialistic attitude toward biology.

Lamarck believed in the ongoing spontaneous generation of simple living organisms through action on physical matter by a material life force.

[27][26] Lamarck ran against the modern chemistry promoted by Lavoisier (whose ideas he regarded with disdain), preferring to embrace a more traditional alchemical view of the elements as influenced primarily by earth, air, fire, and water.

He argued that organisms thus moved from simple to complex in a steady, predictable way based on the fundamental physical principles of alchemy.

He is sometimes regarded as believing in a teleological (goal-oriented) process where organisms became more perfect as they evolved, though as a materialist, he emphasized that these forces must originate necessarily from underlying physical principles.

According to the paleontologist Henry Fairfield Osborn, "Lamarck denied, absolutely, the existence of any 'perfecting tendency' in nature, and regarded evolution as the final necessary effect of surrounding conditions on life.

[31] However, in the field of epigenetics, evidence is growing that soft inheritance plays a part in the changing of some organisms' phenotypes; it leaves the genetic material (DNA) unaltered (thus not violating the central dogma of biology) but prevents the expression of genes,[32] such as by methylation to modify DNA transcription; this can be produced by changes in behaviour and environment.

[34] The philosopher of biology Michael Ruse described Lamarck, "as believing in God as an unmoved mover, creator of the world and its laws, who refuses to intervene miraculously in his creation.

[Note 4] 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".

The International Plant Names Index gives 58 records, including a number of well-known genera such as the mosquito fern (Azolla).