Question

Write the first law of Lamark with an example.

Answer 1

Hint: Lamarck did not believe that a species could become extinct, instead he believed that idea of extinction as every member of a species evolving into another species. He said that change was brought about through use and disuse and inheritance of acquired characteristics. This was the first time in evolution that a mechanism was proposed to explain how a change in a species occurred.

Complete answer.
First of all Jean-Baptiste Lamarck (1744-1829) was a French naturalist. He was a soldier, biologist, and academic, and an early proponent of the idea that biological evolution occurred and proceeded by natural laws. He first proposed a mechanism by which the gradual change of species might take place. So, he was credited with making the first large advance toward modern evolutionary theory. He also extended the definition of the change over time where he said that life started as simple and became more complex with time.
A book called “Philosophie Zoologique”, was published in 1809 by Lamarck in which he described a two-part mechanism by which change was gradually introduced into the species and passed down through generations. The theory given by him is alternatively referred to as the theory of transformation or simply called Lamarckism. In his lifetime he did not receive much recognition but Lamarck's work is considered a major step forward in the present time. The first law of Lamarck explains that in evolution over time, organisms or their parts gradually tend to increase in size. The classic example that is given by Lamarck is about the increase in the neck size of the giraffe due to the concept of use and disuse is the neck. There is an increase in the size of the neck of the giraffe in the course of evolution which helps them to raise the neck and feed on the leaves of the trees. This habit is passed on to the next generation.

Note: A major downfall of Lamarck's theory was that he couldn’t explain how this might happen, though he discussed a "natural tendency toward perfection.". so, his theory got rejected. Lamarck had given other examples like the toes of water birds. He said that due to the straining on their toes to swim through water over years, these birds gained elongated, webbed toes to better their swimming.