A dog breeder selects German Shepherds with the best traits to produce offspring. What level of environmental organization is he working with? *

How do living things obtain phosphorus

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

Me.henley said, “in the rat race we call life, only the strong will survive.” he may have been referring to