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Lamarck was born in the small town of Bazentin in northern France, the scion of an

impoverished aristocratic family. He served in the military during the Seven ears

!ar and, at the age of only "#, was awarded a commission for bravery in

recognition of his actions on the battle$eld. %t was at this point that &ean'Baptiste

(ierre )ntoine de *onet +Lamarcks given name- became the hevalier de Lamarck,

or &ean'Baptiste Lamarck, the name by which he was thereafter known.

Later, when Lamarck retired in/ured, he took up a new career in natural history. He

$rst studied botany under the naturalist Bernard de &ussieu. 0he eventual product of 

this ten'year period of research was Lamarcks Flore fran1oise +"##2-, a three'

volume work on the plant life of France that brought its author into the front rank of 

French naturalists.

%llustrations of scallops from &ean'Baptiste Lamarcks 0ableau encyclop3di4ue etm3thodi4ue des trois r5gnes de la nature, "#26'"276.

%llustrations of star$sh from Lamarcks 0ableau encyclop3di4ue et m3thodi4ue des

trois r5gnes de la nature, "#26'"276.

Lamarck eventually obtained a position at the &ardin des (lantes in (aris, and later

at the *us3um national dHistoire naturelle where he became a professor of zoology. %n "28", he published Syst5me des )nimau9 sans :ertebres, a landmark in

invertebrate ta9onomy. %t was he who originated the distinction between

vertebrates and invertebrates, and who introduced many still'e9isting ma/or

divisions of the latter category, such as crustaceans, arachnids and annelids.

Lamarcks theory of evolution. Lamarck is now best remembered for his proposals

concerning evolution. He was the $rst scientist to formally propose a gradualistic

theory of evolution +as opposed to saltationist theories of evolution such as that

proposed earlier by Linnaeus-. )s ;arwin +

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species. He $rst did the eminent service of arousing attention to the probability of 

all changes in the organic, as well as in the inorganic world, being the result of law,

and not of miraculous interposition.

%n his theory, Lamarck assumed that simple microscopic forms of life continuously

arise spontaneously from nonliving matter. 0his notion that spontaneous generationoccurs on an ongoing basis was still widely accepted in his day. But he further

supposed that such forms had an innate tendency gradually to evolve over time into

organisms of ever greater comple9ity. 0his was something no one else had said.

 0hus in "287, he comments, =;o we not therefore see that through the action of the

laws of organization ... nature has in favorable times, places, and climates

multiplied the $rst germs of animal life, and allowed their organization to

develop, ... and increased and diversi$ed their organs 0hen, ... aided by much time

and by a slow and ongoing diversity of circumstances, she has gradually brought

about in this way the state of things which we now observe. How grand is this

consideration, and especially how distant is it from what is generally thought on this

sub/ectC

Dnder Lamarcks theory, traits could arise, or become more developed, through the

use of an organ or portion of the body. For e9ample, he said the necks of giraEes

had gotten longer as they were used to stretch ever higher for leaves. 0raits could

also diminish, he claimed, through =disuse.= %n this way any organ that went unused

would tend to shrink with the passing generations. For e9ample, he said blind cave

$sh had become blind because their ancestors had not used their eyes.

 0his notion, that traits ac4uired in an individuals lifetime in response to e9ercise or

environmental stimuli could be passed on to descendant generations, was not new.

%n those days, many people, even scientists, thought ac4uired traits could be

inherited +indeed, that very school of thought, despite its long being out of 

intellectual fashion, is again garnering adherents today-.

But many other scientists opposed the idea, most prominently uvier. 0hey ridiculed

the idea with farcical scenarios such as cowboys fathering bowlegged babies or

weight lifters producing muscle'bound children. However, many naturalists freely

embraced the idea, including ;arwin himself. For e9ample, in the

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