1) No, but maybe one day we shall understand how similar is carnivorous nutrition. Further information: http://en.wikipedia.org/wiki/Soylent_Green "Americans consume a million animals an hour. Every second, 300 living beings are slaughtered for food. There are virtually no local, state or federal laws protecting animals, either throughout their lives or during slaughter. Factory farm managers and employees can treat animals in any way they wish in order to maximize profits, with no regard whatsoever for the suffering involved. The one law available, the Downed Animal Protection Act, is seldom enforced." Source and further information: http://www.ocpausa.org/food.htm As long as not all animals have become extinct, and as long as not all other living being have become extinct, if we don't insist in staying carnivorous, we still could eat those. And hopefully, we shall be able to make synthetics foods to replace them. 2) What could eventually happen in the near future, is the growing of human cells or organs outside the body, to replace defective organs. Also, as long as this does not work for everything, organ donation will be used (and unfortunately, in some cases, abused). Further information: http://en.wikipedia.org/wiki/Organ_donation http://en.wikipedia.org/wiki/Organ_theft http://en.wikipedia.org/wiki/Organ_trade 3) "In Niven's universe, it was possible to transplant nearly any organ in the body (and prevent rejection) by the mid twentyfirst century. Since any organ could now be replaced, in theory one could use the organ banks to extend life indefinitely. In practice, however, this was not the case. To maintain communal organ banks, one needs donors (i.e. dead people). When the death rate is reduced (via the organ banks), the number of donors decreases. Therefore the system was fundamentally flawed, as the demand would always exceed the supply. Compounding this problem, the high success rate of organ transplants tended to discourage research into other viable medical treatments. As a result, medical research was stagnated to a large extent, focusing primarily on improving transplants and little else. Repairing a failing organ (which could presumably fail again later) was considered secondary to the "complete" solution of replacing the failing organ." Source and further information: http://en.wikipedia.org/wiki/Organlegging