I was listening to Ask an Atheist and they were talking about extinction of megafauna, which are in themselves cool. Megafauna are animals like elephants and mammoths that are over 45 kg in weight. These are the monsters of nature that at one time dominated life, but now many of them have gone extinct. It is theorized that the rise of humans contributed to their extinction in part by hunting them, but what really interested me is that diseases transferred from humans to these animals might have helped kill them off. Many megafauna fossils show signs of tuberculosis which could have been transferred from humans to these animals. I found it really interesting that these monsters of our past could have been killed off by disease. It just puts it in perspective that the dominate species could be killed off by disease and with out vaccines humans are no exception.