Although this question is incomplete, we can still provide some information that can help guide your answer.
Buffalos (or bisons) were once a common sight in the American plains. While in the early 1800s about 60 million of these could be found across the country, the number was reduced to about 27 by the early 1900s. Government efforts have brought back this species from the brink of extinction.
While often associated with the American West, these animals lived in other regions of the country, including Texas. However, the buffalo population in Texas was not always regular. It varied based on several factors, including many geographic ones. For example, when rain was scarce, vegetation was hard to find. Water was also found in limited supply. This led the buffalo to migrate to other areas. Similarly, areas with fertile soil were used for agriculture, which made the land unavailable to the herds. These are examples of geographic factors that had a significant impact on buffalo in Texas.
Answer: In modern view, the origin of variation is mutation. Since Darwin stated that variation will occurs in the most useful part and is retained, most people don't use their left hands, if according to Darwin's theory, those left hands should be going to extinct by now.
If Darwin's theory of variation is acceptable, then dwarfs who always want to be giant, by stretching the body, would have become giant by now.
Darwin just had a general idea about variation, offsprings tends to change in appearance from the parents. But this variation is not in terms of usefulness of the body parts of the parents, it is in terms of Gene mutation of the parents in their offspring.
Explanation: Darwin's 1859 theory set out a theory of Evolution by natural selection to explain adaptation and speciation.
According to Darwin's theory, individual of one generation are qualitatively different from one another this is as a result of natural selection. But in modern science, this is as a result of Gene mutation.
