Over the past 200,000 years or so modern humans have been developing and many tiny changes have led to our current form. All of us who are alive today are a product of adaptation, evolution, and natural selection. Even though our ancestors may have looked similar in appearance to us, many physical and anatomical things are different these days. Proof of this can be found in the vestigial structures scattered throughout our bodies. Vestigial structures are "genetically determined structures or attributes that have apparently lost most or all of their ancestral function in a given species, but having been retained during the process of evolution (source: Wikipedia). Essentially, mother nature renders certain things absolute or no longer necessary for the survival of a species going forward. Instead of eliminating it all together, it's slowly faded out and rendered useless, but still remains intact. Why certain body parts and functions stay, while others get completely eliminated, is