Explanation:
When Charles Darwin considered some of the unique structures found in modern animals, like the feathered wings of birds, he famously proposed that modern animals must have evolved from earlier forms that lacked those structures. He also predicted that there must have been some intermediate structure between them which may be found in fossils.
Evolution is the process by which certain traits develop within an population, become fixed and make the population's survival more efficient. According to theories of evolution the modern day species were not the same million years ago but they gradually got modified with time and so they differ significantly from their ancestors.
