Why Did They Go Extint?

With the reasearch I did i found three ideas to how they went extinct and i see that ll three are very logical. You cant just blame a single reason why these animals went extinct. The three reasons are human interaction, climate change and last disease. First human interaction would be more along the lines of hunting. With people now hunting them to survive, their numbers would deminish. Another reason that would effect them is because they would gather the fauna that some of these animals would eat and they would have no food. Same goes for the carnivors, they would hunt their food. So food became scare for these animals. The second reason would be climate change. The galciers were melting which would mean temperatures were rising. Also precipitation patters were changing. These changes would effect the food, reproductive cycles, and they were forced to live in conditions they werent adapted or able to live in. The last idea would be disease. As the people interacted with the native fauna they would pass disease on. The aminals werent adapted to this disease and being new to it, it just wiped them out. We saw this as we came to this country and nearly wiped out the Native American population. Honestly who knows which of these are correct. It may just be one or a combination of all three. The world may never know.
http://exhibits.museum.state.il.us/exhibits/larson/LP_extinction.html

                         
                     

Extinct Mammoth

 http://www.ehow.com/how_6008194_search-fossil-bones.html

Extinct Sabertooth Cat      http://www.vectorsite.net/Ybstc_1m.jpg