Sangeetha Pulapaka
-1

Do you know about a cartoon called Jetsons? It was about a family living in the year 2062, where they were flying cars, robots and their meals were in a form of a tablet, which satisfied their hunger.  Mankind has adapted to different kinds of environmental variations until now. As the years go by, because of deforestation there sure will be less than the required number of plants and trees. My guess is like the Jetsons, humans will be living in some sort of a dome and will have devised some artifcial means of survival. We will come to know this for sure, when the researchers find a way to survive in Mars. Both private and public organizations have made commitments to researching the viability of long-term colonization efforts and to taking steps toward a permanent human presence on Mars. 


Some foods not from animal or plant sources include various edible fungi especially mushrooms. More on this from


https://en.wikipedia.org/wiki/Food

RejuvenatedAfricanBuffalo
0

It may be that someday we can survive without plants and animals but it is better to conserve the resources present in the earth so everyone can live in harmony and then we won't need any other food resource.Also there will be no overpopulation by  humans.