Consider the recent past. The deadliest weapon man kind has created was the atomic bomb.Consider that this deadly weapon as about.com informs us took,"Over the course of six years, from 1939 to 1945, more than $2 billion was spent during the history of the Manhattan Project(Mary Bellis, about.com)." (Check out the link for more details)The Manhattan Project was the name of the atomic bomb project. Now this bomb whose power was feared after being tested costed our country billions. If that surprises you, even more shocking was the price of the deadliest weapon our ancestors had: its cost was zero dollars with tax. The deadliest weapons our ancestors had were livestock. The most important factor in determining the relative success of civilization was the extensive use of livestock because it allowed for human populations to become much denser and therefore gave us the secret weapon of germs.
Having livestock allowed many populations to boom. Diamond informs us,"One reason just mentioned is that agriculture sustains much higher human population densities than does the hunting-gathering lifestyle--on the average, 10 to 100 times higher (Diamond, 205). An important part of agriculture is livestock. The reason livestock is so important to the success of a civilization is because it brings a greater means of feeding a village, town, or city. This allowed for populations in the past to not only survive a longer time because they had enough energy, but also to settle down and start forming successful civilizations. The reason the hunter gather life isn't as successful is that they are taking a chance searching for food. For this reason many hunter gatherer groups had to stay small. This ensured that at least the small group would get fed. With livestock and the formation of greater populations, civilizations were a lot more successful.
With the rise of populations and agriculture human societies were both attacked and compensated for the devastation of those attacks. When populations were becoming denser with livestock, our living with the livestock gave diseases a new host. Diseases that our livestock had were passed to humans and often caused many epidemics. However, through evolution we surely adapted and formed barriers against those diseases. The reason disease was so beneficial to human populations was because it wiped out many foreign human populations. The world would not be the same without disease. When European countries set out to conquer foreign countries, the victory of the conquest would never have been possible without disease. Diamond informs us,"Far more Native Americans died in bed form Eurasian germs than on the battlefield from European guns and swords.(Diamond, 210) Without those deadly germs none of the conquererors would have stood a chance against the massive kingdoms they attemtped and succeded in destroying.
The evidence showing how livestock is the most important factor when considering the relative success of any population is irrefutable. However, let's pretend this wasn't so. Let's say that Eurasia for one reason or another never developed agriculture and with that any livestock. This would indeed make Eurasia the "loser" when compared with the Americas. The Americas would become the winners if they had an east-west alignment and the early invention of writing. With two out of the three factors, the Americas would have sooner or later become civilized and developed a form of agriculture. Steve Jones the head of the biology department at the University College London stated,"Humans are 10,000 times more common than we should be, according to the rules of the animal kingdom, and we have agriculture to thank for that. Without farming, the world population would probably have reached half a million by now.(Wikipedia)" While he puts into perpective the world view, if we zero in on just Eurasia we could see the devastating affects of never developing agriculture. This would have changed history dramatically. The Americas would have not been conquered, it's kingdoms might have survived and become more civilized.
There are many factors that tie into making a successful civilization, but of those factors like Diamond points out livestock is the most important. Without livestock dense and thus more civilized populations would have never developed. Without the denser populations germs would have not been so easily transmitted to humans. So many things in history would be much different. Diamond states,"That might not have happened without Europe's sinister gift to other continents-- the germs evolving from Eurasians' long intimacy with domestic animals.(Diamond, 214)" Without the deadly weapon the course of history would be another story.