March 6, 2012
Demise Of Larger Prehistoric Animals Blamed On Climate Change, Humankind
The death and extinction of many large, prehistoric animals may be due largely in part to man´s actions as well as climate change.
The University of Cambridge has conducted new research to determine if humankind played a significant role in the destruction of these prehistoric megafauna. The findings were posted on March 5, 2012 in the journal PNAS.
The research team examined extinctions during the late Quaternary period (700,000 years ago to present day) but focused much of their attention to the last 100,000 years. In this research, the scientists assessed how different factors played a role in the extinction of much of the world´s megafauna. These extinctions included prehistoric giants such as mastodons and sloths in the Americas, Moas or flightless birds in New Zealand, and the wooly rhino in Europe.
The research team collected information about the arrival of humans on each of the five different landmasses (New Zealand, South America, North America, and Eurasia). In addition to this data, they also collected data about the changes in Earth´s climate from the Antarctic ice core. This ice core is a wealth of information, keeping one of the longest running records of changes in the earth´s climate going back several hundred thousand years.
The researchers than conducted a statistical analysis using the information about climate change and the arrival of humankind. The conclusion is that it wasn´t just climate change that brought about the demise of these megafauna, but a combination of climate change and man´s hunting and habitat alterations.
By using this information, the researchers hope that they can prevent modern day large animals (such as tigers and elephants) from succumbing to a similar fate.
"Our research suggests that a combination of human pressure and climate change was able to cause the extinctions of many large animals in the past. Many large, charismatic animals today are threatened by both hunting pressure and changes in climate; if we do not take action to address these issues we may see further extinctions.” said Grahm Prescott, PhD student at the University of Cambridge and the paper´s co-author.
Studies in the past have always argued that drastic changes and shifts in climate were to blame for the extinction of these large animals. Now, with this new research, scientists are starting to believe that direct human pressure in the form of hunting and habitat destruction worked in tandem with the shifts in climate. Professor Rhys Green, an author on the paper and a member of the Royal Society for the Protection of Birds (RSPB) said in the press release: “The key difference this time is that the climate change is not caused by fluctuations in the earth's rotation axis but to warming caused by fossil fuel burning and deforestation by humans - a double whammy of our own making. We should learn the lesson and act urgently to moderate both types of impact."
While this study shows that the actions of humankind can be ultimately destructive to the animals around us, it also gives hope that we can also prevent these kinds of extinctions from ever happening again. Precott stated, “in contrast to the people who first encountered these megafauna, people today are fully aware of the consequences of our actions; this gives us hope that we can prevent future extinctions, but will make it all the worse if we do not."
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