A researcher conducts an investigation on fiddler crabs to understand the importance of claw size in mating. Male fiddler crabs have one normal-sized claw and one giant claw that they wave to attract female fiddler crabs. The female fiddler crabs have two small, same-sized claws. The researcher places 15 male crabs with different sized claws into an enclosure with similar conditions similar to their natural habitat. The researcher then releases 15 female crabs into the enclosure. The graph shows the percentage of male crabs of different claw size that successfully mated for three successive trials.