Homoplasy is also referred to as evolutionary convergence. These traits allow scientists to study adaptation to certain conditions (Danchin, Giraldeau, Cezilly, 2008).
Some examples of convergent evolution: Cactus and euphorb; hippopotamus and capybara; chevrotain and paca; royal antelope and agouti; pangolin and giant armadillo. Upon first glance, one would most likely assume these animals are related, based on their morophogical similarities. However, they actually evolved from unrelated ancestors, who actually looked very different from one another. Even if they don't live in the same place, the environmental stesses they face can be very similar, i.e. deserts or rainforests. Similar traits can evolve to deal with similar stressors. (Ricklefs, 2008).
Danchin, E., Giraldeau, L., Cezilly, F. (2008). Behavioral Ecology. New York, NY: Oxford University Press.
Ricklefs, R. (2008). The Economy of Nature (6th ed.). New York, NY: W.H. Freeman and Company.