(Copyright © 1999 Piero Scaruffi | Legal restrictions - Termini d'uso )
Freeman Dyson is a physicist by profession, and this book is a physicist's
speculations on the origins of life and on the relationship between cosmology
and faith. His immediate aim is to reconcile Physics and Biology, his ultimate
aim is to reconcile Science and Religion.
Dyson believes that one cannot consider life only as metabolism or only as replication. Both aspects must be present. Therefore, we must look not for the origin of life, but for the origin of replication and the origin of metabolism. Since it is unlikely that both metabolism and replication occurred at the same time in one of the primitive organic molecules, life must have had a double origin. It is more reasonable to assume that life "began" twice, with organisms capable of reproduction but not of metabolism and with (separate) organisms capable of metabolism but not of reproduction, and only later there arose a mixture of the two: organisms capable of both reproduction and metabolism.
Dyson's idea is that first came organisms that could reproduce but not replicate. Reproduction is simply a cell division: two cells are created by dividing a cell in two. Replication implies that molecules are copied. Reproduction with replication implies that the new cells "inherit" the molecules of the mother cell. Replication became a parasite over metabolism, meaning that organisms capable of replication needed to use organisms capable of metabolism in order to replicate. First proteins were born and somehow began to metabolize. Then nucleic acids were born and somehow began to replicate using proteins as hosts.
The two organisms became one thanks to a form of symbiosis between host and parasite. Dyson borrows ideas taken from Manfred Eigen (who claims that RNA can appear spontaneously) and Lynn Margulis (who claims that cellular evolution was due to parasites). Basically, his theory is that RNA was the primeval parasite.
Dyson also speculates on the connection between cosmology and biology. Inspired by Jamal Islam, who calculated how matter would evolve in universes which expand forever, Dyson calculates mathematically what life is and how it will evolve. A closed universe is doomed to collapse and life with it. Since a system's entropy is a measure of the number of alternative states of the system, the complexity of a living organism should be proportional to the negative of its entropy. Dyson even computed the entropy of a human being (the rate at which humans dissipate energy times the human body's temperature times the duration of a unit of consciousness): 10 to the 23th.
Life and intelligence are immortal, because sources of memory will grow constantly as the universe cools down. Life is a form of order, and low temperature favors order.
"Life resides in organization, not in substance".