(still very much under construction!)
Food is a blessing and a struggle. We humans are blessed being omnivores enabling us to eat a wider variety of foods than most other mammals on the planet. Being omnivores has enabled us to adapt to almost any ecosystem on the planet for hundreds of thousands of years. Our rich traditions of creation stories and religious ritual often still reflects our gratitude for these fruitful relationships. On the other hand, ecosystems are constantly changing and humans have had to literally dig-in when ecosystems underwent major changes. The Agricultural Revolution (i.e., large-scale farming) was the result, especially in regions of the world that suffered deforestation and desertification since the last ice age, 10,000 years ago. Consequently, many societies have had to learn to rely less and less on our local ecosystem for survival and more and more on their abilities to grow our own food. The bible story, of "falling from grace" in the Garden of Eden, reflects this inevitable shift in Mesopotamia.
Some choose, or are forced out of necessity, to become foragers on the waste of the industrial centers of the world.
The image on the left is from an article in the New York Times on June 21, 2007 titled "Not Buying It."
http://www.nytimes.com/2007/06/26/science/26devo.html?_r=1&ref=science&oref=slogin
series on evolution and development