Science was never satisfied with the creation myths of various religions that explained the origin and development of life on Earth. Charles Darwin, an English naturalist, provided a solution in the form of a theory called the Evolution Theory in 1859.
According to Darwin, the living things we see today have evolved gradually over millions of years. This theory also says that different species may show some similarities because they have evolved from a common ancestor. Charles Darwin explained that different species evolve by a process known as natural selection.
The characteristics of each individual are determined by extremely small pieces of genetic material called genes. Genes are present in the nuclei of the body’s cells. Sometimes, certain changes, known as mutations take place in the genes. These mutations cause the formation of new characteristics in individuals. Some mutations are harmful, and make it difficult for the babies to survive. Animals that possess these harmful mutations may not be able to compete with other animals for food and space to live. Therefore, they will gradually die. Other mutations make animals more fit and able to survive in new conditions. These animals will gradually increase in number. In this way, Nature selects those animals and individuals who are best suited to survive in a changing environment. This is called natural selection.
The giraffe is an excellent example of natural selection. Animals that had longer necks than others were able to reach up higher and get more food. They survived, while those with shorter necks could not compete with them and, therefore, died.
Pictures credit: google