Jean-Baptiste Lamarck's Theory

In this episode, we discussed a number of historically important figures, but we never whittled it down to just one. Topics of conversation included Anaximander, Empedocles, Buffon, Carolus Linnaeus, and Erasmus Darwin. Lamarck, however, is the most important in this context.

It's not usually the theories that scientists hold dear that they are famous for. Since the end of the nineteenth century, the name of the French biologist Jean-Baptiste Lamarck has been intimately associated with the concept of acquired character inheritance. Many historians posit that Lamarck's name is unfairly coupled with the theory that holds his name and that he deserves credit more for being a notable advocate of the concept of biological evolution than for the theory's mechanism, in which he simply followed the conventional wisdom of the era. And that stands to reason.

The essence of individual efforts in the generation of adaptation was significantly reduced with the emergence of Charles Darwin's theory of natural selection. Later, the idea of inheritance of acquired features was replaced by Mendelian genetics, which eventually resulted in the formation of the modern evolutionary synthesis and the mainstream rejection of the Lamarckian theory of evolution in biology.

Lamarckism was largely founded on two observations:

1. Individuals carry on the traits of their ancestors through inheritance of acquired qualities.

2. Use and disuse - People shed traits they no longer need or use and gain traits that are advantageous.

In the episode, we used two instances:

• The first is about how giraffes evolved and how their necks became longer over time as they sought for nourishment and tree leaves. And the giraffes with their iconic long necks from the following generation were born.

• Lamarck also speculated that a blacksmith accumulates muscle in his arms and passes it on to his children, analogous to the giraffe scenario.