Resource exploitation puts humans at greater peril from extinction level event

From the Daily Mail:

Lessons from the end of the dinosaurs: Resource exploitation puts humans at greater peril from extinction level event.

•     Food chains already under strain before asteroid hit, study shows
•     Man's exploitation of resources and reliance on monocrops could place humans in similar danger

The mass extinction of dinosaurs by a massive asteroid was made worse because it destroyed the fragile food chain, lessons that modern man should learn, a study warned.
More than 65 million years ago a mountain-sized asteroid plunged into the earth in Mexico wiping out many species including the dinosaurs and ending the Cretaceous Period of Earth history.
The study found the food chain was already under strain before the asteroid hit and could not cope with the cataclysm as plant life died off.
They warned man's exploitation of the earth resources could place humankind in the same peril as we stress the planet with monocrops and drive to extinction animals, plant life and marine species.
Scientists examining the impact zone of the now-buried Chicxulub crater on the coast of Mexico's Yucatan Peninsula said it had wide spreading knock on effects.
Using a computer model they examined what happened up and down the food chain and found the structure of North American ecosystems made the extinction worse than it might have been.
Jonathan Mitchell of Chicago's Committee on Evolutionary Biology said: 'Our study suggests that the severity of the mass extinction in North America was greater because of the ecological structure of communities at the time.'
The findings suggest a combination of environmental and biological factors meant food webs were already under strain before the asteroid hit, meaning such a large scale disturbance was more likely to have an effect on the survival of species.
Mr Mitchell said: 'Besides shedding light on this ancient extinction, our findings imply that seemingly innocuous changes to ecosystems caused by humans might reduce the ecosystems' abilities to withstand unexpected disturbances.
The study has implications for modern conservation efforts and Mr Angelczyk said: 'Our study shows that the robustness or fragility of an ecosystem under duress depends very much on both the number of species present, as well as the types of species.
'What you have is also important. It is therefore critical that conservation efforts pay attention to ecosystem functioning and the roles of species in their communities as we continue to degrade our modern ecosystems.

Read more: http://www.dailymail.co.uk/sciencetech/article-2224798/Resource-exploitation-puts-humans-greater-peril-extinction-level-event.html#ixzz2AkfZKU5y

http://www.whole-systems.org/extinctions.html

Of course we are now losing species to extinction at a rate exponentially higher than occurred during the time of the dinosaurs.