Hypothetical Biology Question

[flin5845]

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So I have been review Darwinism, and thought of something I do not know is possible.

My thoughts:

If a recessive allele is naturally selected for some species over a dominate allele, is it possible for the recessive allele to eventually become a dominate allele? I was curious because I was reading about moths, and before the industrial revolution most moths were white, because it would allow them to blend in with the light colored linches on trees and how when the industrial revolution occur the soot killed most of the light linches, exposing the dark bark. After that most moths turned black, because they have adapted to their changing environment. I was just thinking that if the dark color for the moth was dominate to the white, then would overtime the white become dominate over the dark? is that possible?

 

[bharat008]

So I have been review Darwinism, and thought of something I do not know is possible.

My thoughts:

If a recessive allele is naturally selected for some species over a dominate allele, is it possible for the recessive allele to eventually become a dominate allele? I was curious because I was reading about moths, and before the industrial revolution most moths were white, because it would allow them to blend in with the light colored linches on trees and how when the industrial revolution occur the soot killed most of the light linches, exposing the dark bark. After that most moths turned black, because they have adapted to their changing environment. I was just thinking that if the dark color for the moth was dominate to the white, then would overtime the white become dominate over the dark? is that possible?

sure it's possible; but don't think about this in terms of alleles. Think about this in terms of what kind of environment is suitable for particular trait. Therefore, to answer your question yes it's possible that black moths could be replaced by white moths sometime in future if conditions favored the survival of white moths.

HOpe that helps..

 

[dansou5]

So I have been review Darwinism, and thought of something I do not know is possible.

My thoughts:

If a recessive allele is naturally selected for some species over a dominate allele, is it possible for the recessive allele to eventually become a dominate allele? I was curious because I was reading about moths, and before the industrial revolution most moths were white, because it would allow them to blend in with the light colored linches on trees and how when the industrial revolution occur the soot killed most of the light linches, exposing the dark bark. After that most moths turned black, because they have adapted to their changing environment. I was just thinking that if the dark color for the moth was dominate to the white, then would overtime the white become dominate over the dark? is that possible?

No that will never happen. I see the logic in what you are saying but a dominant phenotype is a dominant phenotype regardless of how many are in the population. If the genotype has the dominate allele then it will show the dominant trait. Allele frequencies will change, in that the amount of the dominant allele in population will decrease as in this case but the recessive allele will not turn into the dominant phenotype.

Haha this actually made me think of the genotype for dwarfism. This trait is actually a dominant trait. So if you have the DD genotype you will show the dwarfism phenotype. Even though this trait is a dominant trait in genetics, it is definitely not the dominant trait in the population.

Hope this helped....

 

[casper22]

so i have been review darwinism, and thought of something i do not know is possible.

My thoughts:

If a recessive allele is naturally selected for some species over a dominate allele, is it possible for the recessive allele to eventually become a dominate allele? I was curious because i was reading about moths, and before the industrial revolution most moths were white, because it would allow them to blend in with the light colored linches on trees and how when the industrial revolution occur the soot killed most of the light linches, exposing the dark bark. After that most moths turned black, because they have adapted to their changing environment. I was just thinking that if the dark color for the moth was dominate to the white, then would overtime the white become dominate over the dark? Is that possible?

n/m

 

[flin5845]

No that will never happen. I see the logic in what you are saying but a dominant phenotype is a dominant phenotype regardless of how many are in the population. If the genotype has the dominate allele then it will show the dominant trait. Allele frequencies will change, in that the amount of the dominant allele in population will decrease as in this case but the recessive allele will not turn into the dominant phenotype.

Haha this actually made me think of the genotype for dwarfism. This trait is actually a dominant trait. So if you have the DD genotype you will show the dwarfism phenotype. Even though this trait is a dominant trait in genetics, it is definitely not the dominant trait in the population.

Hope this helped....

Yea this makes more sense. The Black would still be dominate, but the frequency would decrease greatly which means the frequency of the recessive allele would increase, and if only recessive alleles were present then the f1 generation would get both recessive genes, therefore the phenotype would be the white.....I started to read more about it and realized that this would happen.

Thanks for your help!

 

[dentalWorks]

So I have been review Darwinism, and thought of something I do not know is possible.

My thoughts:

If a recessive allele is naturally selected for some species over a dominate allele, is it possible for the recessive allele to eventually become a dominate allele? I was curious because I was reading about moths, and before the industrial revolution most moths were white, because it would allow them to blend in with the light colored linches on trees and how when the industrial revolution occur the soot killed most of the light linches, exposing the dark bark. After that most moths turned black, because they have adapted to their changing environment. I was just thinking that if the dark color for the moth was dominate to the white, then would overtime the white become dominate over the dark? is that possible?

Under normal circumstances (with non-sex chromosomes)... If an Individual is heterozygous (say Ww ~ for white), big 'W' is ALWAYS dominate no matter what. The genetic machinery (DNA --> mRNA --> Protein) will always express the big 'W' phenotype.... hence White will always (genetically) be dominate.

However, like the moth example (excellent example btw), natural selection started working against the big 'W'.... all of a sudden, the homozygous recessive allele became the "favorite".... but never the Dominate Allele

and to answer the final question.... yes it is possible if a mutation takes places within the genetic machinery such that the little 'w' now becomes the dominate trait..... but this could take a VERY long time to develop

 

[LetsGo2DSchool]

I believe polydactylism (having 6 fingers) is a dominant allele. However, the overwhelming majority of the human race is homozygous recessive for 5 fingers and thus why you don't see too many 6-fingered people around.

One of the original Amish settlers was a polydactyl freak and thus, there's a large number of 6-fingered Amish people in that neck of the woods in Pennsylvania lol.

Perhaps a 6-fingered person could make a good dentist.