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Wisdom teeth are vestigial third molars that human ancestors used to help in grinding down plant tissue. The common postulation is that their skulls had larger jaws with more teeth, which were possibly used to help chew down foliage to compensate for a lack of ability to efficiently digest the cellulose that makes up a plant cell wall.
In humans, the vermiform appendix is sometimes called a vestigial structure as it has lost much of its ancestral digestive function.. Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. [1]
Vestigial teeth in narwhal. [101] Rudimentary digits of Ateles geoffroyi, Colobus guereza, and Perodicticus potto. [102] Vestigial dental primordia in the embryonic tooth pattern in mice. [103] Reduced or absent vomeronasal organ in humans and Old World monkeys. [104] [105] Presence of non-functional sinus hair muscles in humans used in whisker ...
O. dicksoni retained molar teeth into adulthood, whereas in the modern platypus, the adults only have keratinized pads (juveniles lose their molar teeth upon adulthood). The shape of its beak suggests that O. dicksoni sought prey by digging in the sides of rivers, whereas the modern platypus digs in the bottom of the river.
Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth . It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies among individuals and populations, and in many cases the tooth is missing.
Wisdom teeth (often notated clinically as M3 for third molar) have long been identified as a source of problems and continue to be the most commonly impacted teeth in the human mouth. Impaction of the wisdom teeth results in a risk of periodontal disease and dental cavities. [29] Impacted wisdom teeth lead to pathology in 12% of cases. [30]
Since dental apparatus comes into direct contact with the foods consumed, teeth provide direct and some of the best evidence for the diet that an individual ate in life. [18] The analysis of features on the teeth and jaws such as cavities, hypoplasias and striations can all reveal the sorts of foods that were consumed. [19]
Axolotls have barely visible vestigial teeth, which develop during metamorphosis. The primary method of feeding is by suction , during which their rakers interlock to close the gill slits. External gills are used for respiration, although buccal pumping (gulping air from the surface) may also be used to provide oxygen to their lungs. [ 15 ]