Lamarck Quotes

The thesis that the living creatures have always been composed different species was established in a time where no sufficient observations had been made and when science hardly existed. This thesis is denied every day by those who have made accurate observations, who have long time observed nature and who have had the benefit from studying our musei's large and rich collections. ~ Jean-Baptiste Lamarck

All knowledge that is not the real product of observation, or of consequences deduced from observation, is entirely groundless and illusory. ~ Jean-Baptiste Lamarck

According to Lamarck, there was a force - the 'power of life' - that pushed organisms to become increasingly complex. ~ Elizabeth Kolbert

However, if we consider that all the characteristics which have been cited are only differences in degree of structure, may we not suppose that this special condition of organization of man has been gradually acquired at the close of a long period of time, with the aid of circumstances which have proved favorable? What a subject for reflection for those who have the courage to enter into it! ~ Jean-Baptiste Lamarck

First Law
In every animal which has not passed the limit of its development, a more frequent and continuous use of any organ gradually strengthens, develops and enlarges that organ, and gives it a power proportional to the length of time it has been so used; while the permanent disuse of any organ imperceptibly weakens and deteriorates it, and progressively diminishes its functional capacity, until it finally disappears.
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. ~ Jean-Baptiste Lamarck

All known living bodies are sharply divided into two special kingdoms, based upon the essential differences which distinguish animals from plants, and in spite of what has been said, I am convinced that these two kingdoms do not really merge into one another at any point. ~ Jean-Baptiste Lamarck

Lamarck's Impact

So, how could these "favorable variations" occur?
Darwin tried to answer this question from the standpoint of
the primitive understanding of science at that time.
According to the French biologist Chevalier de Lamarck
(1744-1829), who lived before Darwin, living creatures
passed on the traits they acquired during their lifetime to
the next generation. He asserted that these traits, which
accumulated from one generation to another, caused new
species to be formed. For instance, he claimed that
giraffes evolved from antelopes; as they struggled to eat
the leaves of high trees, their necks were extended from
generation to generation.

Darwin also gave similar examples. In his book The
Origin of Species, for instance, he said that some bears
going into water to find food transformed themselves into
whales over time.

However, the laws of inheritance discovered by Gregor
Mendel (1822-84) and verified by the science of genetics,
which flourished in the twentieth century, utterly demolished
the legend that acquired traits were passed on to
subsequent generations. Thus, natural selection fell out of
favor as an evolutionary mechanism. ~ Harun Yahya

According to the concept of transformational evolution, first clearly articulated by Lamarck, evolution consists of the gradual transformation of organisms from one condition of existence to another. ~ Ernst W. Mayr

Cuvier had preceded Lamarck in specifying the kinds and degrees of variation, which his own observations and critical judgment of the reports of others led him to admit. ~ Richard Owen

In every animal which has not passed the limit of its development, a more frequent and continuous use of any organ gradually strengthens, develops and enlarges that organ, and gives it a power proportional to the length of time it has been so used; while the permanent disuse of any organ imperceptibly weakens and deteriorates it, and progressively diminishes its functional capacity, until it finally disappears. ~ Jean-Baptiste Lamarck

It is not always the magnitude of the differences observed between species that must determine specific distinctions, but the constant preservation of those differences in reproduction. ~ Jean-Baptiste Lamarck