Vestigial Structures
Vestigial structures are those structures in the body which does not have any particular function and are just the residual part of the ancestors. For Examples pelvic bone of snakes, the human appendix, wings of flightless birds. As they don’t have any function in the body but they require extra energy in the body and they can also cause many diseases. Most of them are harmless that’s why they are not removed from the body because removing them requires many alterations and can also cause many side effects in the body. These structures are not useless from the start instead they were very useful in ancient times but along with evolution the functions which were performed by these parts no longer exist so they become useless.
What are Homologous Structures?
Evolution is a continuous process of nature. Any species need to upgrade itself. Thus it can able to survive in a continuously changing environment. This change always occurred in a positive direction. This means after the changing of a creature, they became more developed than the previous version. Evolution works in such a way. It takes millions & millions of years to complete a process. Some scientists believe that Evolution is a never-ending process. It g-oes running for an infinite time. During this process, a creature will be always developed. There are many structures developed during the evolution process of certain species. Homologous Structure is one of them.