Q.The idea of use and disuse of organs for evolution of organism was proposed by (A) Charles Darwin (B) Thomas Malthus (C) Hugo De Vries (D) Lamarck

The idea of use and disuse of organs for evolution was proposed by Lamarck. This is the core of his theory of inheritance of acquired characters. According to Lamarck, if an organism uses an organ extensively, it develops and strengthens; if it is not used, it degenerates. These changes, he argued, are then passed on to the next generation.

The classic example given in the NCERT textbook is the long neck of the giraffe. Lamarck explained that giraffes originally had short necks, but because they constantly stretched their necks to reach leaves on tall trees, their necks became longer over their lifetime. This acquired long neck was then inherited by their offspring. …

To understand this question, you need to step back into the late 1700s and early 1800s, long before Darwin published On the Origin of Species. The natural world was a puzzle, and the first coherent, full-length theory of evolution was put forward by a French biologist named Jean-Baptiste Lamarck. His big idea was that organisms change over time because they actively respond to their environment.

Lamarck’s theory rested on two main pillars. The first was the law of use and disuse. He argued that if an animal used a particular organ constantly, that organ would become stronger, larger, and more developed over its lifetime. Conversely, if an organ was not used, it would gradually weaken and shrink. The second pillar was the inheritance of acquired characteristics — the belief that these changes an animal made during its life could be passed directly to its offspring.

The classic example Lamarck gave was the giraffe. He proposed that the ancestors of modern giraffes had short necks. As they stretched their necks to reach leaves on high branches, the neck muscles and bones became slightly longer. This "acquired" longer neck was then inherited by the next generation, which stretched its neck a little more, and so on, over many generations. The same logic applied to organs that fell into disuse — like the eyes of a cave-dwelling fish, which Lamarck believed shrank because they were never used, and this blindness was then inherited. …