In defense of Self: Immune system

1. Why blood transmission is less repelled than organ transplant? Does that mean blood is less specialized? How immune system recognize this?

2. Most animals eat raw. Do immune systems recognize and differentiate between raw meat and bacteria and attack selectively? Or the digestive system simply digest everything into smaller component which are no more alive?

It may not be very flattering to our egos, but nature does not really have a role for any of us beyond passing on our genes --- beyond simple reproduction. We in fact become a potential problem for the next generation of breeders and their offspring by consuming valuable resources needed by younger members of the species for reproduction. (p. 90)

All cancer cells share one single, common feature: they have lost their ability to regulate DNA synthesis and cell division. (p. 163)

Increasingly, it seems that many, perhaps most, tumors arise within specialized cells that constantly replenish dead or damaged cells within our tissues and organs. Stem cells are in a sense primed to enter cell division more easily than most other cells in our body, and it may take less to get them to cross over to a cancerous state. (p. 165)

Comment: We can put the above paragraph into recommendation about reduce amplitude of future business cycles.