Why are most new mutations recessive?

Answer 1

for each gene, there are usually a number of alleles. An allele, is the same gene, with different coding. While these alleles can be dominant or recessive, many are incompletely dominant, others are co-dominant (such as blood types) and some alleles don't act any different, and could be considered recessive because no change is seen. It's important to remember that lots of alleles have very little effect on an organism. What difference is there if an organism has slightly darker fur, more fur or less fur than the average. Unless conditions change to make these changes desirable.

When we consider Lethal mutations, these are usually recessive each parent with a 'healthy' allele and a Lethal allele. The child has a 25% chance usually of developing a problem. We see more of these, which gives the impression that mutations are recessive.

Lethal mutations that are dominant, die with the individual who has them, unless they are expressed late in life. An example of this is Huntington's disease. It is an autosomal dominant, needing only one affected allele from either parent to inherit the disease. This means you have a 50% chance of having it, if one of your parents has the gene. This is a disease that can be expressed late enough in life, the children and grand children may never know their parents or grandparents passed them the allele.

Answer 2

There are multiple types of effects that result from mutations. The most common effect is a loss of function. Loss of function mutations result in recessive phenotypes (because one good copy of the gene still gives you the phenotype), thus they are recessive alleles. In these cases, usually the recessive gene is the minority.

Some mutations result in gain of function, that is they cause a new protein that causes a new phenotype. Now all you need is a single copy of this mutated gene to get the phenotype, hence it is dominant. In these cases, the dominant allele is the minority (e.g. blood types).

The reason that most mutations are loss of function type (recessive) is because there are many more ways to screw up a gene and/or a protein by mutation then there are to alter or improve its function.

Answer 3

Where on earth did you get the idea that most mutations are recessive?

Silent is not the same as recessive....

and those claiming that they must be recessive... dont really know what they are talking about...

Answer 4

Mutations usually have to be recessive for the individual to survive and pass it on to their offspring. Mutation is a violent process thus for the most part, dominant mutations kill off the individual. However, there are certain dominant mutations that allow individuals to survive and yes there are things called dominant mutations. Just google search dominant human mutations.

Answer 5

why do you believe that? If they weren't recessive, they wouldn't survive. A new mutation that isn't recessive will die out in 1 or 2 generations if it is not beneficial.

Answer 6

ALL mutations are recessive. both parents have to carry the recessive gene and give it to the child in order for the child to be born with that mutation.

Answer 7

For a mutation to be recessive, a man or woman might desire to hold 2 copies of the mutant gene to be affected. illnesses like sickle cellular anemia are handed on while the two mothers and fathers carry one reproduction of the mutant gene and their newborn gets one reproduction from each and each discern.