In tropical regions, freshwater species were especially hard-hit; the index shows they suffered a 35-percent drop between 1970 and 2000." Terrestrial species are affected by over-farming and deforestation: the change has been swift and alarming: The world's wildlife declined by 27% since 1970 overall (Humans blamed, 2008, CNN).
Even domestic animals have suffered from humanity's engineering of the environment. Many cannot life in the wild without the help of humans, given how selective breeding has reduced the capacity of the dog, the cat, and the horse to forage for itself. In the case some animals raised for consumption, such as cattle, humans force them to eat an unnatural diet of corn. Corn-fed cows are fatter than grass-fed cows, but they must be fed antibiotics to be able to digest...
In general, domestic animals have smaller brains and are fatter and less hardy than their wild counterparts: domestication renders them useful to humans, not better-adapted to survive. This parallels how humans have attempted to adapt the world to our needs, rather than adapted our needs to the world and harmed and in some cases destroyed many wild species.
References
Humans blamed for sharp drop in wildlife. (2008, May 16). CNN.com.
Retrieved October 31, 2009 at http://www.cnn.com/2008/WORLD/europe/05/16/wildlife.shortage/index.html
Pollan, Michael. (2002, May 24). Power steer. Michael Pollan.
Retrieved October 31, 2009 at http://www.michaelpollan.com/article.php?id=14
