Until the arrival of Bonnet, it was thought that without insemination there would be no offspring. Bonnet proved that in some species fertilization is not always necessary for the development of a new individual.
(1720-1793) Swiss naturalist and philosopher. He observed that an unfertilized egg could develop into a new individual and that tracheal respiration in insects. He was born on March 13, 1720, in Geneva. He is the son of a family of French origin who settled in Switzerland in the 16th century. After studying law, he started to practice law; however, he devoted more time to natural science, especially to his studies of insects, than to law, which he had been interested in since the age of 16. In 1740 he was admitted to the French Academy of Sciences for his work examining the phenomenon of parthenogenesis in plant lice. He became a member of the Royal Society in London in 1743 and received the title of Doctor of Law in the same year. Bonnet, who was made a member of the Grand Consul in Geneva between 1752 and 1768 and lived a quiet life without leaving Switzerland once, died in Genthod near Geneva on 20 May 1793.
Charles Bonnet (13 March 1720 – 20 May 1793) was a Genevan naturalist and philosophical writer. He is responsible for coining the term phyllotaxis to describe the arrangement of leaves on a plant. He was among the first to notice parthenogenetic reproduction in aphids and established that insects respired through their spiracles.
Until Bonnet, it was known that reproduction in a multicellular organism occurs as a result of the fertilization of the egg cell formed by the female of that species with the sperm cell of the male of that species. Bonnet proved with his studies, especially on plant lice, that fertilization is not always necessary for the development of a new individual in some species, and that an unfertilized egg can also undergo cell division to form a new living thing. This form of reproduction, called parthenogenesis or non-fertilization, is also found in other species other than the species Bonnet studied.
In 1741, Bonnet, who studied reproduction and self-renewal of missing body parts in organisms in the lower stages of evolution, such as freshwater polyps (hydras), earthworms, and algae (bryozoa), observed tracheal respiration in caterpillars and butterflies the following year. Bonnet, who gave the name "crakea" to the long, thin tubes spread throughout the animal's body, and "stigma" to the mouths of these tubes that open to the outside and provide air entry, is the first natural scientist to shed light on the respiration of land-dwelling arthropods.
After publishing his first work, Traite d'insectologie ("An Insectology Study") in 1745, which compiles his various observations on insects, he focused his studies more on botany, specifically examining plant leaves, the function of leaves in nutrition, and the phenomenon of sensation in plants. Recherches sur l'usage des feuilles des plantes ("Investigations on the Use of Leaves in Plants"), published in 1754, is the product of this work.
Explaining that the most important task of leaves is to absorb the moisture rising from the soil, Bonnet, who has been accepted as the greatest expert on plant nutrition for many years, is of historical importance rather than scientific with his experiments and interpretations. As he gradually lost his sense of sight towards the age of forty, he inevitably moved away from his experiments and observations and focused on theoretical studies and natural philosophy. At that time, he put forward the hypothesis of "pre-sowed seeds" that allows living things to reproduce spontaneously and suggested that every female creature carries the seeds of the next generations within itself. Naturally, the "seed" Bonnet spoke of was not the genes and DNA that play a fundamental role in heredity; because at that time even the existence of chromosomes, not DNA, was unknown.
He published his "Analytical Essay on the Spiritual Faculties" examining the physiological conditions of intellectual activity in 1760, and Contemplation de la Nature ("A Glance at Nature") in 1764. This latest book, which claims that all beings in nature, from minerals to animals, show a continuous development from simple to complex without interruption, has been translated into many European languages and has become his most well-known and read work.
Although Bonnet was the first naturalist to use the word "evolution" in these works, he was not a scientist who believed in evolution in today's sense.
Works of Charles Bonnet
Traite d'insectologie, 1745, ("The Insectology Review");
Recherches sur l'usage des feuilles des plantes, 1754, ("Research on the Use of Leaves in Plants");
Essai de psychologie, 1754, (“Essay on Psychology”);
Essai analytiyue sur îes facultes de râme, 1760, (“Analytical Essay on the Spiritual Faculties”);
Considerations sur les corps organ is p, 1762, (“Reflections on Advanced Creatures”);
Contemplation de la nature, 1764, (“View of Nature”);
La palingenesie philosophique, 1769, (“Rebirth in Philosophy”).