The article “The Ancestry of the Giant Panda” surrounds the topic of whether giant pandas are more related to bears (Ursidae) or raccoons (Procyonidae) or have a distinct family of their own. The identification of the family they belong to was done through several experiments. The controversy began in the year 1869, when the giant panda was first described by Pere Armand David. David was the first person to recognize the giant panda as a new species; however, as the controversy got known more worldwide, a lot of scientists started to make all different kinds of assumptions, but all of the ones that did not have true proof could potentially end up being wrong. Scientists could often be confused by big pandas because of their identical characteristics and their homologous genetic basis. In this case, a small morphological change may result from an extensive reorganization of multiple genes and, thus, represent a quantum jump in evolution at the molecular level. There were two concepts that the scientists used to find out the “real” zoological place that the giant pandas belong to. Firstly, the molecular clock hypothesis was one of the powerful evidence to support the idea, which laid the foundation of molecular evolution. The researchers started the research by collecting blood and skin samples from the species in the Ursidae family and the Procyonidae family and made an analysis with DNA hybridization. After this experiment, although they were fairly confident with the result, they still tested it for double confirmation and consistency by comparing mutational differences in genes that code for isozymes. The second technique they used is called two-dimensional electrophoresis. This test estimated the evolutionary distance between species by comparing the extent to which a serum protein from one species will react with antibodies raised against that protein from a different species. In addition, as mentioned in the article, the fewer antibody molecules that bind, the more distant the relationship between the species. From both experiments, they were able to conclude that between 30 to 50 million years ago, the ancestors of the modern Ursidae and Procyonids split into two separate lineages and made a final taxonomic decision that the giant panda belongs to the family Ursidae (the bear family) and that the red panda belongs to the Procyonidae (the raccoon family). This was a very hard decision to make for the scientists because a lot of characteristics that giant panda has does not relate to the those of the bear. The chromosomes could be a great example, where the panda has 21 pairs and the bear has 37 pairs.
About the author: Stephen J. O’Brien
Scientific American
Vol. 257, No. 5 (NOVEMBER 1987), pp. 102-107 (6 pages)
Published By: Scientific American, a division of Nature America, Inc.
Article/author source: https://www.jstor.org/stable/24979550
