What can cause gene frequencies- to change?

Answer 1

Genes make proteins and proteins allow the organism to function. In population genetics, though, what needs to be taken into account is what is going on outside the organism. Genes and proteins and organisms do not function inside a vacuum. The organism lives in an environment that is constantly changing. How well the organism interacts with its environment entails how many successful offspring an organism will have. This is the basis of genetic fitness.
To answer your question, then, environmental changes cause gene frequencies to change. If an organism has a set of genes that allow it to live perfectly in tune with its environment, and suddenly that environment changes, the organism (with its gene set) is now suddenly more fit or less fit in this new environment, and the frequencies of its genes will either go up or down (respectively), due to the fact that it can now have more offspring than it could before.

Answer 2

Environmental pressure:
Example: The "peppered moth" situation: Peppered moths have wing varieties that are dark and white. Prior to the industrial revolution dark and white moths would land on white birch trees. The dark moths were easily seen by birds on the white background and easily picked off. The gene frequency for dark moths was low, and they were rather rare. Along came the industrial revolution and soot from the factories darkened the birch trees. The white moths were now easily seen by birds and picked off. The gene frequency now changed in favor of the black moths; No mutation required!
Wingless flies: Off the coast of Samalia,coastal flies had wings, the gene frequency was 1.0 (100%). A mutation occured (mutations are usually harmful) and some flies were hatched
without wings. Normally this would be bad, but because of the coastal land breeze, the flies with wings got blown out to sea and perrished.The wingless flies just walked around and stayed on shore. The gene frequency changed in favor of the wingless flies, in this case due to a mutation.
Other examples would be : The effects of antibiotics on bacteria, and the effect of DDT (an insecticide) on insects.
Change of gene frequency is an important factor in explaining the modern theory of evolution.

Answer 3

the change of gene frequency is called as mutation. it can happen either spontaneously or by artificial means.

the agent which brings about mutation is called mutagen. and there are many kinds of mutation..

if mutation occurs in a single nucleotide then it is called point mutation. it may be addition, deletion or replacement of a nucleotide.

it is brought about by chemicals, uv rays, heat and etc..

bye

take care

Eniyan. M

Answer 4

Animals with one form of the gene die before reproducing.