If having 6 toes is a dominant trait....?

Question

why dont we all or most of us have 6 toes??

is it cause its a new mutation?

Answer 1

Like Dr. Cancer said, even if it is dominant that doesn't mean it's going to be in the majority of people. If only one in 10000 people have the dominant trait the chances are I'm still going to marry a person who has 5 toes and so my kids are going to have 5 toes.

The same can be seen in the eye colour of Slavic people. Blue eyes are recessive (not technically that simple) but yet are at a high frequency in those peoples. The few people who founded the Slavic peoples probably had blue eyes and thus the population now has many blue-eyed people (despite it being 'recessive').

Answer 2

Having six toes and/or fingers is known as polydactyly.

The reason why we don't all have polydactyly is because the trait is very uncommon. See, even though it is dominant, meaning a couple where one parent has polydactyly is more likely to have more offspring with it than without it, there are still TONS of people out there who DON'T have it who are having just as many kids!

There are TONS of dominant traits out there that are just very rare, and they will never be all over the entire population because there are very few people around to give them to their offspring. And, even if they DO have offspring, they may not necessarily pass it on, as they have a second allele, which could be recessive.

Dominant does not necessarily mean more common, just like recessive does not mean rarer.

If you want an example where recessive is more common, take Huntington's disease. Huntington's is a dominant trait, but it is a very uncommon trait; most people have the non-Huntington's Gene.

Answer 3

I'm not aware of it being a dominant trait.

Answer 4

As others have pointed out - there is no intrinsic reason why a dominant trait with no selective advantage or disadvantage should change in frequency.

A dominant trait will generally only increase in frequency if, for some reason, those with the trait have more children than those without the trait.

If they have less children, the trait will decrease in frequency.

If they have just as many children, then the trait will stay about the same.

Genetic drift - the random change in frequency of a trait without selective pressure - can change the frequency, but it is not as strong a factor as selective pressure. Selective pressure is stronger on dominant traits than recessive ones, however, as you cannot be a "carrier" for the trait.

There are other dominant traits that do not dominate the population: achondroplasia dwarfism, for example, is a dominant trait. Type A blood and Type B blood are both dominant over Type O.

Answer 5

hehe I dont really know about any of this, but I just saw you answer the question on age, country and religion and thought it was really cool that you were christian too and not afraid to say it. It really sucks being thumbs downed because of it, because I wouldn't do that to others. but anyway I jut wanted to say it's cool that you weren't afraid to admit it.

Answer 6

because its weird.

Answer 7

...because having six toes does not lead to a person having more children than a "normal" person would.  There's no selective advantage to the trait, and so the allele frequency will not be increased in the next generation.

Answer 8

I would like to smell your toes!

Answer 9

Well. The person who has 6 toes probably had something messed up in their DNA when they were born. It's a really

severe chance that everyone will end up being born with 6 toes.

This one kid at my school has 4 fingers on each of his Hands, 8 in total. Something got messed up in his DNA. And plus. If we all had 6 toes it would be kinda weird. Lol. It would be kinda hard to find shoes that are really roomy for our toes :)

Answer 10

No Its Not A Dominant Trait It Just Happens Kinda Like The Lottery lol Nah But its not a new mutation either it happened b4 2

Answer 11

It is a dominant trait, but dominant traits do not automatically increase and take over the population.  I get this question all the time, but it is difficult to answer in such a short reply.  Since most of us have the recessive trait, we are all pp (no polydactly).  Therefore, most of us will continue marrying no polydactlies and having 5 finger/toes.  

To change the allele frequency, we think of either artifical selection on our parts or natural selection.