Those big puppy dog eyes are 33,000 years in the making. According to a paper published in Proceedings of the National Academy of Sciences, dogs' faces have evolved to better communicate with humans. Read more about dogs' transformation below.







Those big puppy dog eyes are 33,000 years in the making. According to a paper published in Proceedings of the National Academy of Sciences, dogs' faces have evolved to better communicate with humans. Read more about dogs' transformation below.