are dominant characteristics always more frequent in a population than recessive characteristics? Why?

Answer 1

Absolutely not. Just because a trait is dominant does not mean that it is present in the population to a greater extent.

Not all dominant traits confer a selective advantage in the wild either. For example the trait that causes Huntington's disease in dominant. Huntington's disease is a neuordegenerative disease that always causes fatality. This trait does not make a person more fit for survival. Also achondroplasial dwarfism is a dominant trait and dwarfism surely does not confer a selective advantage to a person.

Here is a great example of why dominant traits are not always present at a higher frequency in a population.
The gene for having 6 fingers is dominant to the trait for having 5 fingers. Very few people have 6 fingers, although some do. A great majority of the population of humans has 5 fingers which means that many more people possess both recessive traits for the number of fingers they posess. (Also the hair color trait given in an earlier answer is a valid example.)

Answer 2

It depends upon the characteristic. Is your question is, are dominant genes expressed more often than recessive genes? If so, then it takes only one dominant mutation for a person to show the dominant characteristic. It takes two recessive mutations (one from each parent) for a persona to show a recessive characteristic.

OR is your question, are dominant genes more common in the general population than recessive genes?

If you are talking about a disease gene, then recessive gene mutations are generally more frequent in a population than dominant ones. For many genetic conditions, having the disease means that you are less likely to reproduce.

Look at Hardy Weinburg. p^2 + 2pq + q^2 = 1. Let's say that p represents the dominant mutation. p^2 represents two dominant gene mutations. For a lot of autosomal dominant genetic conditions (e.g. achondroplasia), the p^2, or homozygous state, is lethal. A personal with one dominant mutation is represented by 2pq. Although this person may survive, the condition may prevent them from having kids OR it may make it more difficult for that person to find a mate. So dominant mutations are continually lost each generation. They get replaced when new mutations pop up at random.

Now let's consider recessive conditions. q^2 represents the person with the recessive disease state. Like the person with the dominant condition, this person may not be reproducing. In recessive conditions, however, a person with only one recessive mutation (2pq) is usually completely healthy. So healthy that they may not even know that they carry the mutation. They reproduce and pass on the gene mutation (q) to the next generation and the next generation.

In other words, natural selection can put serious pressure on dominant mutations, but has a more difficult time weeding out the recessive mutations. So recessive mutations live on.

Answer 3

Certainly not. The definition of population is just a group of people. For example, if the population is that of Sweden, the recessive trait, blond hair, is much more common than brown or black hair. But overall, dominant characteristics become more common over time. However, dominant allele diseases are extremely rare, much more than recessive allele diseases.

Answer 4

Yes, the dominant trait is always more frequent. There are two alleles (two gene forms) for each gene. One allele from the female, and one from the male. If one is dominant, and the other is recessive, the presence of a dominant allele determines the trait. The only time that a recessive trait will express itself is when the dominant trait is absent in the offspring. And this happens only 25% of the time if dominant and recessive alleles are equal in the gene pool. The dominant gene expresses its trait 75% of the time. This means that the dominant trait expresses itself 3 times as often as the recessive trait.

To have a recessive trait expressed, you would have to inherit it from both parents. This would be like flipping a coin twice, and getting tails both times.

Answer 5

Absolutely not!
Dominance and allele frequency in the population are not necessarily related, and are certainly not the same thing. If the dominant trait, for example, usually results in mortality in the womb, you may only rarely see it in the general population. Blonde hair and blues eyes in parts of Scandinavia is another example. Scale-less or partly scaled carp carry the dominant allele; however, fully scaled carp generally predominate in wild populations (probably due to a survival advantage offered by the protection of being fully armored).

Answer 6

Yes dominant characteristics are more frequent otherwise they wouldn't be called the dominant characteristic. The genes for them are most likely to come to play than recessive.

It is like rolling a dice. B=dominant trait and b=recessive trait. So on a dice we have four B's and two b's. You roll the dice and the odds of rolling the B is greater and for the most part (4 out of 6) you are going to get the B.

Answer 7

Yes, the dominant characteristics will be more frequent. Remembering that it takes two alleles to express a trait, if X id dominant and x is recessive, you can have XX, Xx, xX, and xx. In the first three, the dominant trait will be expressed, and only when you have two recessive genes will the recessive trait be expressed. In short, the dominant gene is always expressed when it is present. Good Luck!!

Answer 8

not necessarily...if the dominant trait is more harmful, then the recessive trait will become more frequent as the dominant genes die out without reproducing. i know there are a few diseases that are caused by dominant genes, but most people have recessive genotypes for it. i believe there is a type of dwarfism that's dominant (obviously we aren't all dwarves) and there are plenty of autosomal dominant diseases out there.

Answer 9

yes because the dominant allele shows up in physical characteristics more than the recessive allele

Answer 10

yes surely dominant characters will be most likely to express its allele.