The “Dogs and More Dogs” video presents one of the most puzzling questions in evolutionary biology: how the diversity of dogs evolved from a relatively homogeneous population of wolves. Anthropological data suggests that dogs arose about fifteen thousand years ago. Compared to the history of the earth and most of the organisms that inhibit it, dogs are still very young. It is therefore truly remarkable that a species (wolves), which must have looked somewhat alike, could have given rise to the enormous differences we see between the Chihuahua and the Golden Retriever. The narrator of the video proposed two hypotheses to explain this evolutionary diversification. The “adoption hypothesis” suggests that our human ancestors thousands of years ago came across an irresistible wolf cub, fell in love with it, and brought it home to raise as a pet. Through constant battles with the predatory instincts of wolves, our ancestors were able to artificially select the most docile animal and ultimately domesticate wolves, which became dogs. On the other hand, the “remaining hypothesis” proposes that the domestication of wolves occurred as a byproduct of city development. When humans settled in villages, garbage dumps would inevitably appear. This provided a new ecological niche for wolves: scavengers in human waste. Taming wolves that were not afraid of humans would have an advantage in obtaining food from landfill. Animals that could benefit from this resource would not need to hunt in the wild and would therefore have a better chance of survival. Over the generations, natural selections would favor docility and facilitate its spread among the population of scavenger wolves. This then gave rise to dogs. If dogs are born… half of the article… Their results suggest that some SNPs with a dominant effect (2 to 6 in general) can explain large amounts of morphological differences in dog breeds (70%). This suggests that the evolution of dogs from wolves may have been the result of some very significant point mutations that spread through the population because they produced traits desirable for humans. In summary, while the video provides two possible and seemingly logical models for the evolution of dogs, it fails to explain the genetic basis of selection and other possible mechanisms of evolution. Further genomic studies are needed to better clarify how dogs evolved. Works Cited Boyko, A. R., Quignon, P., Li, L., Schoenebeck, J. J., Degenhardt, J. D., Lohmueller, K. E., ... & Ostrander, E. A. (2010). A simple genetic architecture underlies morphological variation in dogs. PLoS Biology, 8(8), e1000451.