At first, because it could not be shown that changes to the organism acquired during its life were inherited by its offspring. Later, when we learned more about genetics, and ultimately DNA, this rejection was confirmed.
Note though that since a few decades, we know of mechanisms that *do* allow certain changes at the molecular level acquired during the organism's lifetime to be inherited by offspring. This field of study is called: epigenetics.
The use and disuse theory was proposed by Jean-Baptiste Lamarck, a French naturalist, in the early 19th century. Lamarck suggested that organisms could pass on traits acquired during their lifetime to their offspring. This theory contrasted with Darwin's theory of natural selection and is now largely discredited.
Lamarck's theory, known as Lamarckism, proposed that organisms could pass down acquired traits to their offspring. He suggested that an organism could change during its lifetime in response to its environment and these changes would be inherited by its offspring. However, this theory has been largely discredited in modern biology.
Lamarck's theory of evolution, known as Lamarckism, proposed that acquired characteristics could be passed down to offspring. This idea suggested that organisms could develop new traits during their lifetime and then pass them on to their offspring. However, this theory has been largely discredited in favor of Darwin's theory of natural selection, which emphasizes the role of genetic variation and environmental factors in driving evolutionary change.
Lamarck's theory, known as Lamarckism, proposed that organisms can pass on acquired characteristics to their offspring. He believed that traits acquired during an individual's lifetime through its interactions with the environment could be inherited by future generations. However, this theory has been largely discredited by modern genetic research.
The public, due mostly to religious reasons, was not ready for any transmutational theory and Lamarck's theory had no evidence to support it thus scientists of the time did not pay it much attention. Also Cuvier was Lamarck's enemy and denigrated the theory Lamarck developed.
The theory of evolution that believes every organism has an internal vital force is known as Lamarckism, proposed by Jean-Baptiste Lamarck. Lamarck believed that organisms could pass on traits acquired during their lifetime to their offspring, driven by a force he called "vitalism." However, this concept has been largely discredited in modern evolutionary biology.
Lamarck
Lamarck's hypotheses were published in Zoological Philosophical Work written in 1809.
Darwin would not have known anything about genetics, which is why his theory was discredited initially, there was no mechanism for random mutation currently understood. On the other hand, the scientific evidence of the time supported Lamarck's theories, which with new understanding have been more or less discredited (ignoring neo-lamarckism and similar theories) which did not require any undiscovered mechanisms.
Lamarck's theory is based on acquired characteristics. In other words if you break your arm your future children will be born with broken arms.
This is the theory of Lamarck and it is long refuted.
Jean-Baptiste Lamarck was the first person to clearly formulate and present a plausible theory of evolution. Lamarck was a French naturalist who lived from 1744 to 1829.