Natural selection merged with the work of in the 20th century to open up our understanding of evolutionary theory. a. alfred russel wallace b. gregor mendel c. jean-baptiste lamarck d. erasmus darwin e. charles lyell

Acertain species of fish can have either long or short fins. the allele for long fins is dominant over the allele for short fins. a heterozygous, long-finned fish is crossed with a homozygous, short-finned fish. of the offspring, will have long fins and be , and will have short fins and be .