why is the little toe a vestigial structure
April 15, 2014 The Darwinian theory of evolution, though initially ridiculed, did go on to become accepted as the truth about how we came to be. Survival of the fittest is the basic soul of this theory, and that everything unnecessary is eventually disposed off. Evolution takes its own sweet time to do that though; so eventually we are still left over with some souvenir of our ancestors; so here is a list of the top ten vestigial body parts. 10. Vomeronasal Organ Also called the Jacobson s organ, the main function of the Vomeronasal Organ is to function as an olfactory organ in amphibians, mammals and reptiles. It detects pheromones which are chemical messengers to exchange information between animals belonging to the same species. In reptiles however the sense of smell has been shifted from the nose to the tongue, which helps them sense their environment by gathering particles in the air. In humans however, it is believed that these organs, present on either sides of the septum behind the nose, has become vestigial; though not completely non functional, according to recent researches. The effect of pheromones in humans is not as pronounced or sufficiently established, since the sense of smell is not really required to attract members of the opposite sex, no matter what the deodorant advertisements tell you! 9. Erector Pili and Body Hair Remember those goose bumps that you got when you saw вConjuringв? В They are caused by the erector pili which are muscle fibers. When these muscles contract, which is usually caused due to fear or cold, it forces the hair follicles to stand on end. Used as a defense mechanism by animals and our very hairy ancestors, the hair standing up makes them look bigger and more threatening to intimidate a predator or opponent in response confrontation; and when the weather was cold, the raised fur used to insulation by trapping warm air close to the skin. The amount of body hair we possess is way too less and short to be of any importance! You cannot really hope to threaten anyone with your hair standing on end; and neither can it provide any insulation, making it useless. Moreover, for all the women (and men) who strive so hard to remove their hair through waxing and electrolysis; it is a terrible curse! 8. Fifth Toe Have you often been injured by furniture, especially on that all too useless pinky toe? You are not the only one then who has been exposed to it being more of a disadvantage! Used primarily by primates and our tree hugging ancestors for clinging and swinging off branches, they have greatly reduced in size now and have become entirely obsolete. Not required for balance, or mobility in any way; the fifth toe is a body part we donвt really need. В Several mammals have already lost their digits thanks to evolution such as cows, horses, pigs and camels and if man were to follow, it wouldnвt make much difference except maybe much better fitting shoes! 7. Extrinsic Ear Muscles We have all attempted to do Funny things with our faces as children.
If you were the talented group star who could wiggle his/her years, you have your extrinsic ear muscles, also called the auricular muscles to thank. They are a group of three muscles surrounding the outer ear that allows movement of your ears independent of your head. Common in almost all animals, you must have noticed your pets perking up their ears when startled, these extrinsic ear muscles are used to perk up their ears as a sign of alertness or to move them around according to motion of predators or prey. В So as far as function goes, this ability is particularly useless in humans now, making these muscles inherently ineffectual. 6. Plica Semilunaris In simple terms, the plica semilunari is called the third eyelid. You may not know it but apart from our two very prominent eyelids we do possess a small nonetheless third eyelid. If you look closely in the corner of your eye beside the ear duct you will find a small fold of tissue which is nothing more than an accessory eye organ in humans. Shrunken during evolution, this remainder of the once present nictitating membrane is still present in birds, reptiles and few mammals to keep the eyes moist and offer protection, but in humans it has barely any function. 5. Tail bone As one of the rare (and lucky) mammals to not have a tail, there is still a remainder of this part that once existed, in the form of a coccyx. The coccyx normally consists of 3 to 5 rudimentary vertebrae fused into a single bone which now performs the function of an anchor point for the muscles to support the anus in place and also attaches many important ligaments together. It is the end segment of the vertebra hence also referred to as the tailbone. There have been cases where people have been born with tails which usually occurs if the signal that stops the elongation of the vertebrae is not given at the right time. its major function was as a support to the limbs while swinging over branches among our ancestors which slowly disappeared with time. As good as they looked on avatar, I am sure none of you will like to have tails- forget wearing pants, sitting down would become a task! 4. Male Nipples It is known why women have nipples- logically for breastfeeding babies but this organ, strangely is present in males as well! During the early pregnancy all embryos have similar tissues and develop nipples during the third and fourth week along with mammary ridges called the milk lines. When the pituitary glands begin to develop, testosterone is produced around the seventh week to develop male sex glands to differentiate the genders. The milk lines recede leaving behind a pair of nipples and lobules which are milk producing glands. Bizarrely the male nipples are not completely vestigial since it is possible for them to lactate though due to presence of milk ducts; if stimulated by the female hormone oestrogen! In a В fairly strange condition called witchesв milkв, some babies have known to lactate at the moment of birth when born with enough of his motherвs oestrogen. 3.
Appendix A narrow tube with a diameter between 7 and 8 mm, connected to a pouch like structure of the colon called cecum, the appendix is located near the junction of the large and the small intestine. Used to digest tough foods like tree barks for our ancestors, it has become a vestigial organ with little or no major function in digestion for our present food choices, though recently it has been discovered that the appendix does produce certain hormones and compounds that help in biological functions in fetuses as well as immune functions in young adults. Uses aside, it has been a source of much discomfort due to a very common condition called appendicitis, the appendix has needed surgical removal. It is characterized by inflammation causing pain, fever and nausea due to blockage. 2. Tonsils One of the most removed organs, tonsils are basically collections of lymphoid tissue one on each side of the back of the throat. They do function as a part of your immune system fighting infections as the first in line for defence in the throat. The major problem with its bacteria fighting effect is its tendency to get sore and inflamed and recurring infections. If the infection is virus initiated, antibiotics donвt help and doctors almost always recommend getting tonsil removal surgery called tonsillectomy which makes it more profitable to not have them in the first place. 1. Wisdom Teeth Our tooth development follows a timely order, and these teeth at the extreme back of our jaw begin to form around the age of 10, and finally erupt at the age of 18-22. They are dubbed wisdom teeth since this is the age in which we are said to become wise. It is believed that our third set of molars, or wisdom teeth as they are commonly called, were present to help chew coarse and rough food items such as nuts, roots and raw meats which formed the diet of our early ancestors. But in recent times with softer, cooked food these wisdom teeth have become practically obsolete in utility. В Some people are born without any wisdom teeth, while there are a good number who need to get one or more extracted due to lack of room in the mouth, misalignment or partial eruption through the gum, which could cause infection and decay. As a result these vestigial organs are more a source of pain and late offerings to the tooth fairy. They seem to have lost much of their immune system function, though the argument over their vestigial status is not settled. Vestigial structures are structures that have lost their original function, but can be still useful. Creationists mistakenly think that vestigial means ' useless ', which it does not. The tonsils seemed to be organs of first line defense against ingested pathogens which now seem to be somewhat dangerous is some people to keep past a early developmental stage.
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