Michel Adanson

Michel Adanson (7 April 1727 – 3 August 1806) was an 18th-century French botanist and naturalist who traveled to Senegal to study flora and fauna. He proposed a "natural system" of taxonomy distinct from the binomial system forwarded by Linnaeus. The standard author abbreviation Adans. is used to indicate this person as the author when citing a botanical name.

Adanson was born at Aix-en-Provence. His family moved to Paris in 1730. After leaving the Collège Sainte-Barbe, he was employed in the cabinets of R. A. F. Réaumur and Bernard de Jussieu, as well as in the Jardin des Plantes, Paris. He attended lectures at the Jardin du Roi and the Collège Royal in Paris from 1741 to 1746. At the end of 1748, funded by a director of the Compagnie des Indes, he left France on an exploring expedition to Senegal. He remained there for five years, collecting and describing numerous animals and plants. He also collected specimens of every object of commerce, delineated maps of the country, made systematic meteorological and astronomical observations, and prepared grammars and dictionaries of the languages spoken on the banks of the Sénégal.

After his return to Paris in 1754 he made use of a small portion of the materials he had collected in his Histoire naturelle du Senegal (1757). Sales of the work were slow, and after the publisher's bankruptcy and the reimbursement to subscribers, Adanson estimated the cost of the book to him had been 5,000 livres, beginning the penury in which he lived the rest of his life. This work has a special interest from the essay on shells, printed at the end of it, where Adanson proposed his universal method, a system of classification distinct from those of Buffon and Linnaeus. He founded his classification of all organised beings on the consideration of each individual organ. As each organ gave birth to new relations, so he established a corresponding number of arbitrary arrangements. Those beings possessing the greatest number of similar organs were referred to one great division, and the relationship was considered more remote in proportion to the dissimilarity of organs.

In 1763 he published his Familles des plantes. In this work he developed the principle of arrangement above mentioned, which, in its adherence to natural botanical relations, was based on the system of Joseph Pitton de Tournefort, and had been anticipated to some extent nearly a century before by John Ray. The success of this work was hindered by its innovations in the use of terms, which were ridiculed by the defenders of the popular sexual system of Linnaeus; but it did much to open the way for the establishment, by means principally of Antoine Laurent de Jussieu's Genera Plantarum (1789), of the natural method of the classification of plants.

In 1774 Adanson submitted to the consideration of the French Academy of Sciences an immense work, extending to all known beings and substances. It consisted of 27 large volumes of manuscript, employed in displaying the general relations of all these matters, and their distribution; 150 volumes more, occupied with the alphabetical arrangement of 40,000 species; a vocabulary, containing 200,000 words, with their explanations; and a number of detached memoirs, 40,000 figures and 30,000 specimens of the three kingdoms of nature. The committee to which the inspection of this enormous mass was entrusted strongly recommended Adanson to separate and publish all that was peculiarly his own, leaving out what was merely compilation. He obstinately rejected this advice; and the huge work, at which he continued to labour, was never published.

Adanson was an early proponent of the inheritance of acquired characters and a limited view of evolution. Historian of science Conway Zirkle has noted that "Adanson was Lamarck's predecessor at the Jardin Royal, and Lamarck could hardly have remained unfamiliar with Adanson 's publications. Adanson not only described evolution in his "Familles de plantes", published in 1763 when Lamarck was a young man of twenty, but also suggested that the changes in specific characteristics were produced through the inheritance of acquired characters."

In an article for the Histoire and Memoires de l'Academie Royale des Sciences of 1769, Adanson used the term "mutations" to refer to small changes that could bring about new variations in individuals. Despite being described as a "precursor of evolutionism" by historians, Adanson rejected the concept of species, preferring to focus on individuals and denied the transmutation of species.

Adanson made a serious attempt to classify fungi based on their fruit body complexity. He was the first botanist to classify lichens with fungi.