Jean-Baptiste Lamarck
Proposed an early theory of evolution based on the inheritance of acquired characteristics, though later superseded by Darwin's theory.
Most quoted
"It is not the organs, that is to say, the nature and form of the parts of the body of an animal, which have given rise to its habits and its particular faculties. It is, on the contrary, its habits, its manner of life, and the circumstances in which its ancestors have found themselves, which have, in the course of time, really constituted the form of its body, the number and state of its organs, and, in short, the faculties which it possesses."
— from Philosophie Zoologique, 1809
"Second Law: All the acquisitions or losses wrought by nature on individuals, through the influence of the environment in which their race has long been placed, and hence through the influence of the predominant use or permanent disuse of any organ; all these are preserved by reproduction to the new individuals which arise, provided that the acquired modifications are common to both sexes, or at least to the individuals which produce the young."
— from Philosophie Zoologique, 1809
"It is not the organs, that is to say, the nature and form of the parts of the body, that have given rise to their habits and particular faculties, but it is, on the contrary, their habits, their manner of life, and the circumstances in which the individuals of which the race is formed have found themselves, that have with time constituted the form of the body, the number and state of their organs, and finally the faculties which they possess."
— from Philosophie Zoologique, 1809
All quotes by Jean-Baptiste Lamarck (412)
The differences between species are not fixed, but are the result of gradual modifications over time.
The will of the animal, when it is strongly directed towards an object, can produce changes in its organs.
The earth is a living body, constantly undergoing changes and transformations.
The simplest animals are those that have the fewest organs and the most uniform organization.
The action of the environment is the primary cause of the diversity of species.
The existence of life is a necessary consequence of the laws of nature.
The development of the nervous system is proportional to the degree of intelligence of an animal.
The more perfect an animal is, the more complex its organization.
The extinction of species is a natural process that has occurred throughout the history of life.
The study of fossils provides evidence for the changes that have occurred in the earth and in life over time.
The human species is not an exception to the laws of nature, but is subject to the same processes of change and development as other species.
The universe is governed by immutable laws that determine all phenomena.
The transformation of species is a slow and gradual process that takes place over immense periods of time.
The diversity of life is a testament to the power and creativity of nature.
The study of nature is the only path to true knowledge.
The internal organization of an animal is a reflection of its external environment.
The development of intelligence is a consequence of the increasing complexity of the nervous system.
The struggle for existence is a fundamental principle of nature.
The earth is constantly being reshaped by the action of water and other natural forces.
The organization of animals is not a fixed plan, but is constantly adapting to new circumstances.
Contemporaries of Jean-Baptiste Lamarck
Other Biologys born within 50 years of Jean-Baptiste Lamarck (1744–1829).