just a true-false?

Question

"Dominant genes produce evolutionary benefits."...I told my teacher that this question was too vague on the test but she said I shouldn't be...I guessed false because they don't produce the benefits, mutations/natural selection are responsible for that....the genes become dominant.....I don't know though..

Answer 1

Huntington's Disease is a lethal autosomal dominant, and doesn't benefit anyone. I don't see any evolutionary benefits to Huntington's. There are plenty of other dominant genes that are deleterious.

The correct answer would be "false." Tell your teacher I said so, and tell her to look up "Huntington's Disease."

Answer 2

I can understand your confusion. The question should perhaps have read "Evolutionary benefits produce dominant genes". That is, if a genetic mutation is beneficial, and dominant, it will have persisted in the population.
However, if two animals of the same species have the same benefit, one caused by a dominant gene, the other by a recessive, the one with the dominant gene will increase in the population.
It is not a simple true/false question, it requires a short answer, at the very least.

In response to emucompboy regarding Huntington's Disease - in the vast majority of cases HD adversely affects people only after they have had children, that is why it has persisted. It has not had an evolutionary effect. By the time that it is diagnosed, it is too late. We now have a genetic marker test for it, but most people with HD in the family avoid having the test, because it will affect things like insurance, healthcare, getting a mortgage etc, and also they don't want to know that when they turn 40 they will start to deteriorate into a horrid, incurable state.

Answer 3

There are many kinds of variations on the level of DNA and chromosomes, any of which can be beneficial or detrimental. If a dominant allele of a gene increases the fitness of the organism than it is beneficial, but this is a two way street, it will more likely be detrimental. True is the correct answer, but it would be better if phrased as, "Dominant genes can produce evolutionary benefits".

Answer 4

i would say you answered this question right. dominant jeans dont produce evolutionary benefits, they just decide what trait will be expressed. the dominant gene could be an evolutionary benefit or an evolutionary downfall.