Jean-Baptiste Lamarck was a French natural scientist who researched evolution issues in particular. The scientist held a different view of evolution than Darwin, whose theory of natural selection eventually became generally accepted. Lamarck believed that organs that the animal does not use gradually disappear in its offspring or are modified based on conditions. For example, a giraffe’s neck is stretched because it needs to reach the foliage on the tops of trees, and the anteater’s tongue has become long to penetrate the anthill. Thus, useful traits are passed to the offspring, and useless ones disappear. Thus, Lamarck presents a different approach to evolutionary biology since he speaks not about adaptations but about the loss of traits, which is still a part of natural selection (spochron100, 2021). Although the scientist’s theory was not generally accepted, he described some aspects correctly, but from a different point of view. However, he also proposed the wrong idea that organisms do not need reproduction to change traits and can change their characteristics at will.
Lamarck also studied zoology, created the classification of animals, and was also the first to divide organisms into vertebrates and invertebrates. His main work is “Philosophie zoologique,” created in 1809, and is the first description of his evolution theory. In this book, Lamarck describes the basic principles of the occurrence of traits in animals, which formed the basis of his theory. The scientist does not use the word evolution but admits that nature created organisms gradually from a simple to complex. Thus, he suggests that complex species evolved from more primitive ones. For example, according to Lamarck, reptiles could have descended from fish. Thus, scientist believed that the main reason for the development of species is changing the environment and related needs. In his work, he also distinguishes vertebrates and invertebrates for the first time and also divides animals into 14 classes.
Reference
spochron100. (2021). Lamarck lecture by Sharon Pochron [Video]. YouTube.