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Proposed an early theory of evolution based on the inheritance of acquired characteristics, though later superseded by Darwin's theory.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 human condition is a testament to the power of evolution.
The meaning of our existence is found in our connection to the natural world.
True beauty is found in the functional elegance of living systems.
It is not the organs themselves which have given rise to the needs and faculties, but the needs and faculties which, by their prolonged exercise, have gradually drawn forth the organs.
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.
The constant use of an organ strengthens it, develops it, and increases its size, proportionate to the length of time it has been used.
Nature, in her operations, never makes leaps.
The environment acts on the form and organization of animals, and consequently on their habits.
It is not the will of the animal that directly modifies its organs, but the new needs that arise and maintain the movements that modify them.
The more frequently and sustainedly an organ is used, the more it develops and strengthens, and the more its size increases.
Every change that is wrought in an organ by a habit of using it, or by a new need, is transmitted by generation to the offspring, provided that the change is common to both sexes.
The production of a new organ in an animal body is always the result of a new need that has arisen and continues to be felt.
Nature has made all the bodies that exist, and has given them their properties.
The organization of animals is not fixed and immutable, but is subject to change over time.
The earth is not eternal, but has undergone immense changes over vast periods of time.
The simplest forms of life are spontaneously generated from inorganic matter.
The progress of nature is not always direct, but often involves deviations and retrogressions.
The classification of animals should be based on their organization and not on arbitrary characters.
The internal sentiment of animals, when it is excited by a need, determines the movements that lead to the satisfaction of that need.
The fluids of the body, by their movements, can produce changes in the organs.
Contemporaries of Jean-Baptiste Lamarck
Other Biologys born within 50 years of Jean-Baptiste Lamarck (1744–1829).