Homo Sapiens Sapiens (Humans) Evolved From Earlier Hominids.

Thanks to Muted for accepting this wonderful debate.Arguments- Cutis Anserina One notable feature our hominid ancestors had that are useless to us i.e, mutations/natural selection would be Cutis Anserina or goosebumps. Animals today such as humans, dogs, cats, and porcupine may get goosebumps when they are cold, frightened, agitated, or surprised. This reason these are created is because in cold situations, the rising hair traps air between hair and skin to create a sensation of warmth. In response to frightening or agitating situations, the influx of hair will make a creature appear bigger, warding off any foes or such, these are useless to humans because, once our ancestors started wearing clothes and advancing to a point when natural enemies weren't common, these became useless, the process of natural selection disposed of the thick hair but left the mechanism for the cutis. Vomeronasal organ <img src="http://listverse.wpengine.netdna-cdn.com/wp-content/uploads/2009/01/gray51-tm.jpg" height="282" width="400" border="0" hspace="4" vspace="4" alt="Gray51" /> At a time when our ancestors were unable to communicate, they used an organ that humans today still have, although useless, called the Vomeronasal organ or Jacobson's organ. This organ was used by our ancestors to detect pheromones useful for triggering sexual desire, alarm, or finding food trails. Humans are born with this vestigial structure but through the advancement of social structure, communication, and technology, this organ has become useless. Plantaris Muscle <img src="http://listverse.wpengine.netdna-cdn.com/wp-content/uploads/2009/01/gray1242-tm.jpg" height="244" width="400" border="0" hspace="4" vspace="4" alt="Gray1242" /> The plantaris muscle is a muscle used by modern animals who are able to grip and handle objects usefully with their feet, such as we use our hands today, this is observable in many great apes today i.e, gorilla, chimpanzee, orangutan, gibbon, etc. This was also useful for our tree-dwelling ancestor, Australopithecus Africanus, however these muscles are very useless for humans today, so underdeveloped that today it is often times removed by doctors to be used for reconstruction in other parts of the body. Another vestigal struture. Wisdom Teeth <img src="http://listverse.wpengine.netdna-cdn.com/wp-content/uploads/2009/01/wisdom-teeth-01-en-tm.jpg" height="243" width="400" border="0" hspace="4" vspace="4" alt="Wisdom Teeth 01 En" /> Another structure useful to our ancestors, but virtually useless to us would be, wisdom teeth, these extra setof molars were useful for our ancestors because they needed to chew and eat shoots and leaves quickly enough to burden a suffiecient amount of plant nutrients today, this was also useful for them because our ancestors weren't as efficient at digesting cellulose as us, the larger teeth could grind up the food and made it digestible. As hominid evolution progressed, diets changed, jaws grew considerably smaller, and wisdom teeth were virtually useless, so far as to some human populations have completely stopped growing these teeth. Coccyx <img src="http://listverse.wpengine.netdna-cdn.com/wp-content/uploads/2009/01/sacrum-tm.jpg" height="325" width="400" border="0" hspace="4" vspace="4" alt="Sacrum" /> The coccyx is the tailbone that lingers in humans today, as the name implies, this was once useful for a tail by our ancestors, as the pelvis evolved, our ancestors began to walk upright and trees weren't very commonplace to hang out, although useless as a tail appendage, it is still useful today; it is now used by humans to support various muscles and support someone when they sit down or lean back. The coccyx is also useful for supporting the positioning of the anus, another vestigal structure. Appendix <img src="http://listverse.wpengine.netdna-cdn.com/wp-content/uploads/2009/01/gray536-tm.jpg" height="315" width="400" border="0" hspace="4" vspace="4" alt="Gray536" /> Another internal organ very useful for our ancestors that is virtually useless for humans today would be the appendix. Often times becoming inflamed or infected and causing horrific abdominal pain, to the point where it must be removed. It's use by our ancestors was to help digest and process the cellulose found in their plant based diet. Of course through evolutionary changes, a plant based diet of today's omnivores is quite irrelavent. Another interesting spetacle created through natural selection was the slection of larger appendices because they were substanstially less likely to become inflamed or disease, another vestigal structure. References- http://listverse.com...