Some people are born with widsom teeth and some are not; is this enough evidence to prove that this is due to evolution? An article written by geneticist Leremy Colf from Standard University discusses this issue. The question of evolution is proposed by a person who shares the absence of wisdom teeth with their father; however, their mother, brother and sister were all born with them. Colf states that in order for the absence of wisdom teeth to be the result of evolution three things must be true.
The first is that there must be two traits. We know this is true because some people are born with wisdom teeth and some are not, plain as that. Second, the trait must be due to DNA. Colf explains that this is not as simple to prove. This has yet to be proven among scientists; some believe poor diet and hygiene could be the cause. The linkage to DNA is crucial to whether or not this trait is due to evolution because the linkage to DNA allows the trait to be passed on to future generations.
Lastly, the frequency of the trait must increase over time. This is dependent upon whether or not the absence of wisdom teeth puts those indivuals without them at an advantage. We do not need our wisdom teeth to chew the types of food we eat today but it is not necessarily true that the people who do not have them are at an advantage. It is just more convenient to be born without the teeth; our jaws are smaller than they used to be and therefore there is less room for the wisdom teeth resulting in problems among those individuals who have them.
So, until all three of these factors are proven to be true, this question still remains unanswered.
I have always been fascinated with the fact that some people are born without teeth. Whether it is evolution or it has just been past down as a genetic defect? I work for an orthodontist, so I am exposed to this rather frequently.
ReplyDeleteIn the case of evolution, as humans progressed, as far as their diet is concerned, there seems to be less of a need for 3 sets of molars. The food we eat today does not need extensive grinding. I feel that congenitally missing teeth may be due to a genetic mutation rather than evolution though. Some research shows that familial tooth agenesis (missing teeth) is transmitted as an autosomal dominant, autosomal recessive, or X-linked genetic condition. (see reference: http://dentalresource.org/topics13.htm). Seems to me that the gene associated with the formation of teeth has a mutation (a change in the genetic sequence) that is able to be passed down generation to generation as an inheritance trait, rather than time altering the gene.
I agree with you, the fact that the third molars seem to be more a burden in today's day and age. I would like to see this question be answered: has evolution created this genetic alteration or if this is just a random gene mutation that has become an inherited trait?
@Jordan
ReplyDeleteOne could say that "a random gene mutation that has become an inherited trait" is the definition of evolution. Evolution comes from new mutations that somehow have an advantage over other forms of the gene. These new mutations nearly always arise through random mutation (another option would be mad scientists performing planned mutations on humans to select for new traits). So to answer your question, evolution does not create genetic alterations, it simply selects random gene mutations that are beneficial.
I naturally do not have wisdom teeth and have always joked with friends that I am the evolved human being.....but interestly enough...all three of my children (boys) all have their wisdom teeth and all three have had to have them removed. So if it were that I was so called "evolved" wouldn't at least one of my children have also received that trait? So, I think I was just somehow luckily mutated. :) I also do not have frontal sinuses (the ones that are above your eyebrows)...wonder if they are somehow related?
ReplyDeleteHi Tanya,
ReplyDeleteSometimes changes in our DNA get passed on to our children, and sometimes they don't. It depends on what kind of cells get the mutations. For women specifically, only the DNA in your egg cells will get passed on to your children. So if the DNA in your mouth got a mutation, it could affect your teeth, but not be passed on to your children. Or you could have a mutation in an egg cell, but not in the cells of your body (think of Down Syndrome). There are all sorts of reasons that wisdom teeth might not grow, and many of them come from causes that have nothing to do with genetics. The wisdom teeth and sinuses might be related, but they also might not. It is too hard to tell.
I'm genetically missing all 4 wisdom teeth along with 2 other molars. I'm the 1st in my family that we know to have this. I really hope that my son and daughter carry this trait as well.
ReplyDelete