Walmart assistant managers average $45,000 a year, which is right on target for the national average salary, according to Glassdoor salary data. If you factor in bonuses and additional compensation, the average pay increases to $48, 311 a year.
Natural selection can only work on existing variation within a population. Such variations arise by mutation, a change in some part of the genetic code for a trait. Mutations arise by chance and without foresight for the potential advantage or disadvantage of the mutation.
Natural selection and selective breeding can both produce changes in animals and plants. The difference between the two is that natural selection occurs in nature, but selective breeding only occurs when humans intervene. Selective breeding is a process where we choose the characteristics we want in an animal.