was born in Bazentin-le-Petit, Picardy on August 1, 1744. Born into
poor nobility (hence chevalier - knight), Lamarck served in the
army before becoming interested in natural history and writing a
multi-volume flora of France. This caught the attention of Georges-Louis
Leclerc, Comte de Buffon who arranged for him to be appointed to
the Muséum National d'Histoire Naturelle in Paris.
years working on plants, Lamarck was appointed curator of invertebrates
— another term he coined. He began a series of public lectures.
Before 1800, he was an essentialist who believed species were
unchanging. After working on the molluscs of the Paris Basin,
he grew convinced that transmutation or change in the nature of
a species occurred over time. He set out to develop an explanation,
which he outlined in his 1809 work, Philosophie Zoologique.
developed two laws:
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
2. 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.
saw spontaneous generation as being ongoing, with the simple organisms
thus created being transmuted over time (by his mechanism) becoming
more complex and closer to some notional idea of perfection. He
thus believed in a teleological (goal-oriented) process where
organisms became more perfect as they evolved. During his lifetime
he became controversial; his criticism of the palaeontologist
Georges Cuvier’s anti-evolutionary stance won him no friends.
married three, possibly four, times. His first marriage was to
his mistress from 1777, Marie Delaporte, the mother of his first
six children, whom he married on her deathbed in 1792. He remarried
in 1795 to Charlotte, but she died in 1797. His third wife was
Julie Mallet in 1798. She died in 1819. Rumours exist of a fourth
wife and widow but no documentary evidence exists of her.
died penniless in Paris on 28 December 1829.
His defenders believe he is unfairly vilified today. They note
that he believed in organic evolution at a time when there was
no theoretical framework to explain evolution. He also argued
that function precedes form, an issue of some contention among
evolutionary theorists at the time. On the other hand, the inheritance
of acquired characteristics is now widely rejected.
Weismann disproved the theory by cutting the tails off mice, demonstrating
that the injury was not passed on to the offspring. Jews and other
religious groups have been circumcising men for hundreds of generations
with no noticeable withering of the foreskin among their descendants.
However, Lamarck did not count injury or mutilation as a true
acquired characteristic, only those which were initiated by the
animal's own needs were deemed to be passed on.
the idea of passing on to offspring characteristics that were
acquired during an organism's lifetime is called Lamarckian. This
view was, until very recently, thought to be inconsistent with
modern genetics, until the discovery of epigenetic inheritance.
The memetic theory of cultural evolution could be considered a
form of Lamarckian inheritance of non-genetic traits.
not only praised Lamarck in the third edition of The Origin of
Species for supporting the concept of evolution and bringing it
to the attention of others, but also accepted the idea of use
and disuse, and developed his theory of pangenesis partially to
explain its apparent occurrence. Darwin and many contemporaries
also believed in the inheritance of acquired characteristics,
an idea that was much more plausible before the discovery of the
cellular mechanisms for genetic transmission.
pejorative use of terms like Lamarckian stems from the confusion
of students on the mechanisms of evolution. Even when natural
selection is explained properly, students tend to think of traits
being selected by the organism. It is also sometimes easier to
say that "trait X was beneficial so the population got trait
X" than to say "trait X was beneficial, individuals
without trait X were less likely to propagate, resulting in the
population having mostly individuals with trait X." This
is a problem related to anthropomorphizing the subject.