Étienne Geoffroy Saint-Hilaire

Étienne Geoffroy Saint- Hilaire ( born April 15, 1772 in Etampes, † June 19, 1844 in Paris) was a French zoologist. His only son was the zoologist Isidore Geoffroy Saint- Hilaire.

Life

Étienne Geoffroy Saint- Hilaire was born in the village of Etampes near Paris, the youngest of fourteen children. His father Gerard Jean Geoffroy was a lawyer. The young Geoffroy Saint- Hilaire ( this is his full last name) first strikes an ecclesiastical career. Hilaire attended the Collège d' Etampes, and then studied at the Collège de Navarre in Paris. There promoted Abbé Henri -Alexandre Tessier (1741-1837) and the botanist Antoine Laurent de Jussieu, his struggle with nature doctrine. His original clerical interests shifted abruptly with the onset of the French Revolution. So he followed his father's recommendation and picked up the law school. He received his diploma in 1790 In August 1792 several of his teachers and colleagues were arrested by Jacobins. ; he undertook - with his life - a rescue attempt, which was only partially successful. Later in 1788, he nevertheless completed a degree in theology and canon is temporarily in the town of Sainte Croix in his hometown. Then he followed his true passions for medicine and the natural sciences, and began at the Collège du Cardinal Lemoine to study. It was the events of Professor Mathurin Jacques Brisson of Natural History, who influenced him. But many other scientists of his time, René -Just Haiiy, Antoine Laurent de Lavoisier and Claude -Louis Berthollet.

He attended the lectures of Louis Jean -Marie Daubenton at the Collège de France and Antoine François de Fourcroy at the Jardin des Plantes. In March 1793 Louis Jean Marie Daubenton gave him, at the intervention of Jacques Henri Bernardin de Saint -Pierre, the position of assistant candidate sous- garde et d' assistant in the Muséum national d' histoire naturelle. By adopted on June 10, 1793 Law of the original Jardin du Roi (Royal Garden ) is converted to the Muséum national d' histoire naturelle, and Hilaire is one of the twelve appointed professors of this newly constituted museum. To him, the Department of Zoology has been assigned. In the same year he dealt with the formation of a menagerie at the facility. There he learned the natural historian Jean -Baptiste Lamarck know and gave the still unknown Georges Cuvier a job as an assistant. With this trio, the museum had great influence on the development of the paleo- biology in the 19th century, see also Paris Academy dispute of 1830.

Together with Cuvier Hilaire wrote five articles on the natural history ( Sur la classification of mammifères, 1795). In his book Histoire des Makis, ou singes de Madagascar (1796 ) he brought his first view of a unified plan in the history of living things to express. He accompanied Napoleon Bonaparte troops from 1798 to 1801 as a scientist to Egypt ( Egyptian Expedition ).

In September 1807, he became a member of the French Academy of Sciences. From 1809 he worked as a professor of zoology at the University of Paris intensively with anatomy. 1818 appeared the first part of his philosophy anatomique, which four years later, the second part.

In his late years Hilaire dealt mainly with organic abnormalities. In 1840 he went blind, a few months later he suffered a stroke and had his offices on.

Scientific achievements

In philosophy (1818-1822) developed Hilaire anatomique the theory that the body of vertebrates and invertebrates has a common basic blueprint. Since - according to his view - has been in the development of species no jumps, would itself become redundant bodies today as rudiments find (such as the Zwischenkieferbein ).

Hilaire tried the physique of vertebrates and invertebrates to analogize and found his way down (modern as homologies referred ) to a theory of the unity of the design unité de plan, to a theory of the analogies, from which he concluded that the evolution of organisms from a single blueprint, plan d' organization can be inferred. However, by this hypothesis, he got into an argument with Georges Cuvier, known as the Paris Academy dispute (1830-1832), who postulated a splitting into four different and independent basic building plans in the animal kingdom. The dispute was persecuted in Europe, Johann Wolfgang von Goethe - with whose views largely coincided Hilaire - switched on. His former colleagues G. Cuvier was also an advocate of catastrophe theory or Kataklysmentheorie.

Hilaire discovered many similarities between diverse vertebrate and came to the conclusion that birds descended from prehistoric reptiles. He was thus the first to postulate a continuing development between fossil and extant organisms. On the other hand, he did not believe that there are forms development in the present.

Through various experiments, he realized that environmental influences can cause malformations in embryos of vertebrates. Considered together with Johann Friedrich Meckel the founder of teratology, the teaching of malformations.

In 1822, he suggested that the segments of arthropods and the spine of mammals are each examples of a unified plan of organization of the animals. This consideration is controlling with regard to the effect of the Hox genes, a family of regulatory genes whose gene products as transcription factors, the activity of other, functionally related genes in the course of individual development ( morphogenesis ), quite topical.

Through his comparative studies in anatomy, embryology and paleontology Hilaire gave the modern theory of evolution decisive impulses.

Moreover, he led lively correspondence, such as with George Sand, who greatly admired him. More friends are, inter alia, Jules Michelet and Henri de Saint -Simon.

Honors

The mammal species Callithrix geoffroyi, Inia geoffrensis, Ateles geoffroyi, Nyctophilus geoffroyi, Anoura geoffroyi, Dasyurus geoffroyi and Leopardus geoffroyi are named after Étienne Geoffroy Saint- Hilaire. Likewise, the birds Schistes geoffroyi, Neomorphus geoffroyi geoffroyi and Geoffroyus.

Writings (selection )

• Philosophy anatomique. In 1818.
• Histoire naturelle of mammifères. From 1820 to 1842. - 7 volumes
• Mémoire sur plusieurs deformation de l'Homme du cranium, suivi d'un essai de classification of monstres acéphales Mem Museum Hist. Nat., VII, 1821, 85-162.
• Des faits et anatomiques physiologiques de l' anencephaly, anencephaly Observes sur un humain né à Paris en mars 1821. Dans philosophy Anatomique, tome II, 1822, 125-153.
• Note sur un monstre humain ( anencephaly ) trouvé dans les ruines de Thèbes en Egypte par M. Passalacqua, Arch Gener. de Médecine, X, 1826, 154-126.
• Description d'un monstre humain, né avant l' ère chrétienne, et Considérations sur le caractère of monstruosités dites anencéphales, Ann. Sc. Naturelles, VII, 1826, 357-381.
• Principes de philosophie zoologique, discutés in mars 1830 au de l' Académie royale be des sciences. Pichon & Didier, Paris 1830 ( online).
• Notions synthétiques historiques et physiologiques de philosophie naturelle, Paris 1838.