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Proposed an early theory of evolution based on the inheritance of acquired characteristics, though later superseded by Darwin's theory.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 more frequently and sustainedly an organ is used, the more it develops, strengthens, and increases in size.
The more an organ is disused, the more it weakens, deteriorates, and diminishes its faculties, and finally disappears.
The development of organs and their faculties is always in direct relation to the needs which have made them necessary.
The true cause of the diversity of animals is the diversity of the circumstances in which they live.
Nature does nothing in vain.
The progress of organization is always from the simple to the complex.
The influence of circumstances is not direct, but acts through the needs and habits of animals.
The changes that occur in the organization of animals are always in harmony with the changes in their environment.
The existence of life is a purely physical phenomenon.
The earth is not immutable, but subject to continuous change.
The waters of the sea are continually changing the surface of the globe.
The laws of nature are immutable and eternal.
The true philosopher is he who observes nature without prejudice.
The classification of animals must be natural, not artificial.
The distinction between species is often arbitrary and artificial.
Nature proceeds by insensible gradations.
The more perfect an animal is, the more complex is its organization.
The influence of the environment is the primary cause of the diversity of forms in living beings.
The needs of animals are the true causes of their actions.
The study of fossils provides undeniable proof of the changes that have occurred on the surface of the globe.
Contemporaries of Jean-Baptiste Lamarck
Other Biologys born within 50 years of Jean-Baptiste Lamarck (1744–1829).