I was wondering how the environment can affect the genotype of a population over certain periods of time. Just like we all know of Lamark's theory of evolution that talks about this condition happening. I am open to any thoughts.

1 hour ago, Wanjala Joseph said:

how the environment can affect the genotype of a population over certain periods of time

Through mutations and selection.

Epigenetics does not mean that the genotype is changed. It means that there are changes in how the genotype is expressed. This can be acquired during a lifetime, and it turns out, that some of these changes can be given further to the offspring. 

some genos will be favored, and individuals possessing the favorable genotypes will continue to reproduce. environmental factors such as water and ultraviolet radiation from the sun can affect genotypes as well

12 hours ago, Illumina said:

some genos will be favored, and individuals possessing the favorable genotypes will continue to reproduce. environmental factors such as water and ultraviolet radiation from the sun can affect genotypes as well

What has this to do with epigenetics?