Dr. Tim Caro's Paper on Wallace
Alfred Russel Wallace co-discovered the theory of natural selection but then fell under the shadow of Charles Darwin in scientific history books. Very recently, however, since the anniversary of his death 100 years ago, there has been a realization that he made enormous contributions to our understanding of biogeography, biodiversity, and coloration as well as natural selection (http://www.bbc.com/earth/story/20161104-the-other-person-that-discovered-evolution-besides-darwin).
Tim Caro recently summarized Wallace's classification of animal and plant coloration into 6 functional categories and reviewed them in the light of modern understanding of coloration. Wallace missed little and his classification scheme that is still highly relevant today. Wallace pointed out extraordinary examples of external appearances in nature that still demand explanation (http://www.sciencedirect.com/science/article/pii/S0169534716301781).