Jean-Baptiste Lamarck: Biography, Facts & Contributions

Instructor: Julie Zundel

Julie has taught high school Zoology, Biology, Physical Science and Chem Tech. She has a Bachelor of Science in Biology and a Master of Education.

When you think of evolution, Charles Darwin probably comes to mind. But other scientists help pave the way for Darwin, including Lamarck. This lesson will look at Lamarck's life, and his contributions to science.


Imagine two giraffes that are the same height. One of the giraffes prefers eating shorter plants, while the other giraffe chooses to forage on taller plants. The giraffe eating shorter plants does not need a long neck, so (over time) its neck will shorten.

The other giraffe, however, will stretch his neck to reach the taller plants, which will eventually result in a longer neck in his lifetime. When each giraffe reproduces, he will pass on the longer or shorter necks off to his offspring.

Giraffe neck length is a classic example of Lamarcks theories.

This idea of evolution was proposed byJean-Baptiste Lamarck, a French naturalist who lived from 1744-1829, and was termed Lamarckism. Today, our understanding of evolution has changed and we know this giraffe scenario doesn't happen, but Lamarck's ideas influenced other scientists, like Charles Darwin, and helped to shape our current understanding of how species change over time.

Before we delve further into Lamarckism, let's take a moment to learn a little more about the life of Jean-Baptiste Lamarck.

A portrait of Lamarck from 1893


Lamarck's science path did not begin immediately, as his family had hoped he would become a priest. He was born in 1744, and was the youngest of 11 children. Three of Lamarck's older brothers joined the military, so it was no surprise when his parents wanted him to do something different (hence the priest path).

Lamarck began his priest training at Jesuits at Amiens, where he continued studying until his father died. From that point, Lamarck left the school, enlisted in the military, and went to war as a teenager.

Lamarck's bravery on the battlefield helped him move quickly up the ranks, and he became a lieutenant. While in the military, Lamarck was injured in an off duty game, and was eventually discharged.

After the military, Lamarck worked in Paris as a bank clerk, and then went back to school to study medicine and plants. In 1778 he was hired to work in the royal garden until 1793, when the gardens became the Museum of Natural History.

Lamarck was appointed as Professor of Invertebrates, which was one of the less prestigious positions. Even though in wasn't glamorous, and Lamarck knew very little about invertebrates, he put all of his effort into the job. He wrote numerous books about invertebrates, and his contributions to the area are seen today.

Not many people appreciated Lamarck's work until after he died, and he lived much of his life in poverty. In 1818 he began to lose his eyesight, and eventually became blind. He had been married four times, and had several children. His daughters took care of him after he became blind until his death in 1829.


Lamarck is best known for his contributions to evolution, so let's highlight those here. While working with fossils at the Museum of Natural History, Lamarck noticed that species seem to change over time. He wrote a book in 1801 entitled Theory of Inheritance of Acquired Characteristics, where he said an organism could pass on the traits he acquired during his life.

Remember the giraffes from before? The giraffe that got a longer neck passed it on to his offspring. Lamarck also suggested that generations of species become more complex over time. For example, the simple organisms, like single-celled organisms, would evolve into more complex organisms. Species did not go extinct; instead they just became a more complex species.

Today we know that Lamarck's contributions to evolution are flawed. That being said, they helped to put evolution on the map, and suggested that the environment had something to do with how or why species changed. Lamarck's writings aided Charles Darwin, and our present-day understanding of evolution.

While Lamarck is linked to evolution, he made other contributions. Let's check out some other Lamarck facts.

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