Ancient Human Expansion and the Mass Extinction of Species

Naruya, S. Kyushu Museum. 2002. February 2, 2007

The Great Leap Forward

History of human life begins at 100,000 to 50,000 years ago in Africa. Human capabilities in that period progressed significantly. Although it is still not known exactly what factors leads or triggers to this progress. But the man in this era has had the ability that resembles modern humans in general. They have a growing brain capacity and able to create the technology and language skills which are more advanced than the other sub-human species.
The Great Leap Forward also marked a major advance human expansion out of Africa and conquers the other sub-human species. Just as how the Neanderthals went extinct by the expansion of the Cro-Magnon in Europe around 40,000 years ago. In addition to expansion into Eurasia, the great human expansion was also marked by the colonization of other continents like Australia around 30,000 to 40,000 years ago. Expansion to North and South America is still not possible due to the impassable barriers across the whole width of Canada during much of the Pleistocene Ice Age.
The colonization of humans into the Americas began around 14,000 to 35,000 years ago (experts still have disputes on this). World's first civilization remains in the Americas can be found throughout Alaska, Canada, Mexico, Amazonia, and Patagonia. The most famous discovery of an ancient civilization was located in Clovis, New Mexico. This is why the ancestral of Native American called by the terms of Clovis. The discovery of many Clovis sites throughout North and South America is quite shocking because the archeological-dated method founds that modern human colonization in America took place very quickly. Only less than 1,000 years human has spread over the North and South American continents.
So the Great Leap Forward marked a new stage in human life. In a short time, humans have spread to various continents and adapt to diverse climates. From the Europe cold climate, equatorial tropics climate, and the southeastern Australian dry and wet terrains. This early humans have advanced technology. From fishing hook, bone needles to sew warm clothes, and hunting equipment that allows humans to kill dangerous animals from a safe distance.

Mass Extinction of Ancient Species

We live in a zoologically impoverished world, from which all the hugest, and fiercest, and strangest forms have recently disappeared. — Alfred Russel Wallace (1876)

Many major mass extinction events happened long time ago. In the last 500 million years (a window of time in which animals has evolved to exploit the vast majority of habitats on earth) there have been around six mass extinction events. For what caused this mass extinction is not obvious, and for some of them, the evidence may have been worn away completely. But meteorite impacts, massive volcanic eruptions, and movement of the solar system through a galactic gas cloud are attributed as a few explanations.
Extinction is a fact of nature. All of the species of animal that live on earth at some point will become extinct. Some, through the process of evolution, may give new forms to their descendents to exploit different niches while others may disappear, leaving no line of descent. As an example, the Permian-Triassic mass extinction created an opportunity for the dinosaurs to rise to dominance. Then, 65 million years ago, another mass extinction event ended the dominance of these reptiles. Eventually, the mammals were successful, and they evolved remarkably quickly to fill the void in the post dinosaur world.
Humans, as part of the mammals, share the benefit of this opportunity and evolved with their Great Leap Forward in 100,000 to 50,000 years ago. Their expansions to the other continents surely have a tremendous impact to the environment they settling in. For million years, most of the animals of Africa and Eurasia continent survived into modern times because they had co-evolved with the protohumans presence. But it’s a contrast comparing to the animals which is exist outside the Africa and Eurasia when they were evolved with the absence of human presence. The species which evolved without the presence of human were lacking particular specializations or were less adapted to the human threat than their African and Eurasian relatives. Prehistoric hunter-gatherers humans presumably walked up to these unafraid animals and kill them too.

Humans almost certainly contributed to the demise of some of the ancient animals, either directly (hunt for food) or indirectly (as the results of fire or habitat modification caused by humans). Ancient human civilization such as hunter-gatherer tribes killed animal for food. This overkill hypothesis concludes that human involvement takes apart to the extinction of species. From the flesh eating birds and saber-toothed marsupials of South America; wooly mammoth and rhinoceros of Eurasia; moas of the New Zealand; giant lemurs of Madagascar; to the golden toad of Costa Rica, which became extinct as recently as 1989.

This view has been challenged with the climate hypothesis which emphasized to the change in climate instead of human involvement that caused the extinction of species. But it does not make sense when they had already survived the ends of 22 previous Ice Ages and then have chosen to massively drop dead almost coincidentally with the sudden presence of human hunters. The problem is that the human population is growing out of control. As the human population grows, more and more pressure is placed on the natural world. They destroy natural ecosystems to make space for their own. Unfortunately, ancient humans did not aware with the heavy consequences for subsequent human history.

The Fate of Humanity and the War on Other Species

Without some knowledge of evolution one cannot hope to arrive at a true picture of human destiny. — Julian Huxley, Evolution in Action

The capacity to expand and utilize our advancement has become blessing for the future foundation of humankind. But in the contrary, it was also become a curse when our capacity to transform nature dramatically has increased the global environmental risk. The Great Leap Forward has changed our relationships with animal and nature. Humans refused being controlled by nature and now they overcome to mastering the nature. But what it takes to mastering the nature? Is it by devastating all living being? We find that Australia lost 94 per cent of their ancient animals so called Megafauna. While North America lost 73 per cent, Europe lost 29 per cent, and Africa south of the Sahara lost 5 per cent. I was devastated to find this horrifying over-extension of human capabilities and how their nature to destroy things.
We must accept, the impact of our species on late Pleistocene ecosystems was rather small in many ways, compared to recent cataclysmic social ecological impact in the modern era. But what happened in the past could help us to understand our present actions. The war on other species reflected the dominance of commercial end; let alone the subjugation of human labor. It reflects our desire to pursue the great purpose in life called prosperity. Without some knowledge on our own history of evolution, we can not hope to arrive at true picture of human destiny. Humans already sequester an astonishing 40 percent of the entire terrestrial primary production of the Earth for selfish use; in terms of loss of natural habitat or reduction in the viability or outright mass extinction of species. Does prosperity so valuable that we willing to sacrifice everything including nature?
We should begin to acknowledge the historical implications of the fact that our species has socially evolved into a colonizing, polarized, class-divided, and conflict-ridden assembly of walking ecological disasters. The truth is by destroying our environment we are also destroying ourselves. Unfortunately, you can look people at different stages of change. There are people who acknowledge their true nature and just about ready to make a change, there are people who are aware of the issues but not really interested in taking any actions, and there are people who will not even give a shit that there's a problem. But I believe that by understanding the history, people can be given an understanding of self and life purpose. Like our great ancestor, we may not aware with the consequences. But thanks to the lesson we might avoid that disaster. Stephen Jay Gould once remarked that dinosaurs should be a term of praise, not of opprobrium because they reigned for more than 120 million years and died through no fault of their own.  So unless we act soon to drastically reverse our current ecocidal course, we will have graced this planet for a far shorter time than our mighty reptile forebears.

Reading source:
- Jared M. Diamond, Guns, Germs, and Steel: The Fates of Human Societies (New York: W.W.Norton, 1997)
-  Franz J. Broswimmer, Ecocide: A Short Story of Mass Extinction of Species, (London: Pluto Press, 2002)