Mitosis and meiosis are both 2 different kinds of cell division process. In mitosis, a parent cell will divide and produce 2 daughter cells that are genetically identical to both the other daughter cell and the parent cell. Since this process produces identical cells, it is mostly used in growth, tissue repair etc.
On the other hand, meiosis is the cell division process where a parent cell produces 2 daughter cells, and the two daughter cells produces 4 more daughter cells, and these daughter cells are genetically different to each other, they only have half of the chromosomes than its parent cell. Meiosis is used in producing gametes, so that when 2 gamete fuse together, in fertilization, the zygote can retain the correct amount of chromosome.
Therefore, since skin is not used in reproduction and its chromosomes should be the same as the original skin cell, mitosis is the answer.
I'm assuming this is the same image that was posted before, therefore the answer is "gene flow" which occurs through population groups by natural selection and other factors.