Sexual reproduction produces genetic variability, thus there are more opportunities for an organism to inherit a new and more favorable genetic combination increasing the likelihood that the organism will survive and reproduce in future different environments. True Genes that are linked together on the same chromosome cannot be randomly distributed to gametes. They segregate together unless crossing over breaks them apart. Look at the ratio of black guinea pigs to white guinea pigs in the offspring. Hemophilia is X-linked recessive.
Color blindness is X-linked recessive.
All daughters will not be affected. Phenotype An individual's phenotype is a result of not only his or her genetic makeup, but also the environment in which the individual lives. Both external and internal environments affect gene expression which then could affect an individual's phenotype. If so, genes that are far apart will have a greater probability of having a cross over between them than those close together. This is descent with modification over generations, as new environments produce new selective forces.