a population of ground squirrels has two pheotypes for coat color: light (bb genotype) and dark (BB or Bb genotype) in their foothills habitat, dark squirrels are very visible and only survive about 75% as often as the light mice. What is the strength of selection against BB and Bb genotypes? - about 0.25 - about 0.75 - cannot be determined - it is different for BB or Bb.