How are little toes and wisdom teeth vestigial structures?

Question

My biology class was talking about evolution today and little toes and wisdom teeth being vestigial structures was mentioned and I don't actually know how they are.

Answer 1

Vestigial structures are anatomical structures of organisms in a species which are considered to have lost much or all of their original function through evolution. These structures are typically in a degenerate, atrophied, or rudimentary condition or form. Vestigial structures are often referred to as vestigial organs, though not all of them are actually organs.

Although the structures most commonly referred to as "vestigial" tend to be largely or entirely functionless, a vestigial structure need not necessarily be without use or function for the organism. Vestigial structures have lost their original main purpose, but they may retain lesser functionalities, or develop entirely new ones.[1] Thus, a "vestigial wing" need only be useless for flight to be vestigial; it may still serve some other purpose than that of a wing.

Wisdom teeth are vestigial third molars that human ancestors used to help in grinding down plant tissue. It has been postulated that the skulls of human ancestors 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. As human diet changed, a smaller jaw was selected by evolution, yet the third molars, or "wisdom teeth", still commonly develop in human mouths

...the one who went, "Wee, wee, wee!" all the way home. (For those with deprived childhoods, I'm talking about little toes.) They're one more body part that is in the way, all too easily injured, and, when you stop to think about it, useless. We don't use them in walking. In parts of the world where people go barefoot most of the time, little toes missing through accident or disease are quite common, and don't hinder the person's mobility at all. Think we need them for balance or something? Our cloven-hoofed fellow mammals get by with two toes on the ground. Horses manage to be mighty fast with just one! Predatory mammals generally put four down. Do we need the extra because we're bipedal? Ostriches are on their feet all day, and can outrun anybody you know--how many toes do they use? Think about it: other primates have prehensile toes. Kids notice right away that monkeys really have four hands. A fifth digit is pretty useful if you're scrambling through branches (and secondarily manipulating objects). Our little fingers are truly useful and probably in no danger of disappearing. But we quit climbing in trees with our rear "hands" and they became feet--which explains why they have useless fifth digits.

Answer 2

Vestigial Structures In Humans

Answer 3

Human Vestigiality

Answer 4

They are vestigal structures because they aren't used much any more, but way back in human or evolutionary history they were.
Wisdom teeth were used for eating raw meat, for ripping it off the bone. Most of us don't do that anymore.
We don't really use our little toes to grip onto anything, but way back, our evolutionary ancestors probably did.

Answer 5

Both aren't used anymore, but have not had time through evolution to completely disappear.

Little toes aren't needed for balance.

Wisdom teeth aren't needed to grind hard plant material.

Answer 6

For the best answers, search on this site https://shorturl.im/8DnLW

Vestigial structures are those that have lost their primary or main function through the evolutionary process, although they may still maintain some kind of function. One of the best clues to whether a structure is vestigial is the presence of similar, functional structures in other organisms. The technical definition of vestigial organs is an organ for which the function does not confer enough of a survival advantage to be retained via evolution, as compared to the random effect of mutation. For instance, canines and felines have the ability to make endogenous (self-produced) vitamin C; this ability is coded in the form of a series of functional genes within their DNA. Primates, including humans, have lost the ability to make the vitamin endogenously, although they retain a non-functional copy of the gene within their DNA. This broken gene is a vestigial structure: it was functional at one time but has since lost that quality. Each of the structures that you describe above has functional analogues in other parts of the animal kingdom, but humans have lost the primary function in each case. The coccyx is the remnant of what would be the bones of the tail; it still serves as a point of muscular attachment, but obviously no longer functions as a tail. Many animals have the ability to move their ears to more closely determine the direction of incoming sounds (e.g., felines, canines, deer, and horses). Humans retain those muscles, but they are mostly nonfunctional; even in people who can move their ears, this ability has a negligible effect on hearing. In animals that have significant amounts of fur, the ability to move it (termed piloerection) has a significant effect on heat retention. Humans have lost essentially all of their body hair, but do retain the muscles of piloerection; erection of hair can still be achieved but has little effect. Similarly, the muscles that move the big toe are responsible for grip and stability in tree-dwelling primates. Obviously, this ability has little significance for humans today. The wisdom teeth were useful when humans ate diets consisting primarily of plant matter; large, flat teeth are useful for grinding down plant tissue, which was essential when human diets were plant-heavy. We lack the ability to efficiently digest cellulose, which could be compensated for to some extent by the increased mastication resulting from wisdom teeth. Since then, we have also changed diets to de-emphasize plant matter with a corresponding increase in protein. As such, wisdom teeth have little purpose today; for many people, the jaw has also regressed to the point where the wisdom teeth do not fit within the bone and must be removed surgically. The appendix is a remnant of part of the cecum, which in herbivores is more developed and responsible for the digestion of cellulose from plants. Humans have since switched to a more protein-heavy diet, and the function of the cecum in digestion of plant matter has since become much less important.

Answer 7

Several factors have been found to be important in causing third molar problems and malocclusion. The most important factor is probably diet, but the influence of other factors including mutations, needs to be examined more fully to understand why wisdom teeth are more often a problem today. The once common belief that wisdom teeth problems are related to putative evolutionary modifications has now been discredited, and we can do no better to summarize this change in belief then to quote MacGregor. MacGregor concluded in an extensive study that the ‘increase of brain size at the expense of jaw size’ evolutionary view is invalid and that the:


‘Evidence derived from paleontology, anthropology, and experiment indicates very convincingly that a reduction in jaw size has occurred due to civilization. The main associated factor appears to be the virtual absence of inter proximal attrition, but initial tooth size may have some effect. Jaw size and dental attrition are related and they have both decreased with modern diet. Jaws were thought to be reduced in size in the course of evolution but close examination reveals that within the species Homo sapiens, this may not have occurred. What was thought to be a good example of evolution in progress has been shown to be better explained otherwise.’110

The findings noted in the many studies cited above, such as tooth and jaw sizes are generally harmonious in societies with a course diet, have forced many evolutionists to reevaluate their theory and postulate that reduction in jaw size ‘ … during hominid evolution has been accompanied by a general reduction of tooth size. Natural selection has presumably operated to maintain a harmonious tooth to jaw size relationship by tending to eliminate genotypes that produced teeth too large for the changing skeletal system.’111

Some evolutionists now even argue that ‘selection against excessively larger teeth would have been stronger then selection for small faces.’112 Why ‘small faces’ would have been selected for is difficult to determine.

The ‘most identifiable remains of fossil mammals consists of teeth’ because they are by far the most durable parts of the body.113 Consequently, the teeth can provide major evidence for or against a theory of morphology change. In this case the research indicates that the problems experienced with wisdom teeth in modern society are not due to mutations selected by the environment but largely to changes in diet, namely to softer, less abrasive processed foods which do not give the teeth the workout which they require to ensure proper relationship in the mouth