4 Self and the Phenomenon of Life
b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity “9x6”You may ask, “Instead of self, why not focus on evolution, or genes,
or molecules, or DNA, or, in a more abstract context, replicators?” My
answer is, evolution is not a fundamental principle. Rather, it is the prod-
uct of interaction between the variation in heritable traits and changing
environmental constraints, and hidden behind the two is the self’s unwav-
ering goal to survive. On the other hand, to define life in terms of mole-
cules is too restrictive, as we do not know whether the molecules of life
in remote parts of the universe are the same as those on Earth. The topic
of “replicator,” especially in relation to genes and DNA, deserves special
elaboration and is presented below.
Although the importance of natural selection is indisputable, the
substrate of natural selection is elusive and has changed over time. First, it
was the organism that was selected. Next, after the discovery of genes and
mutation, the genome became the unit of selection. Subsequently, in the
1950s when DNA was discovered to carry the genetic information, DNA
and genes were taken to be one and the same, and the focus was shifted to
the DNA molecule. It was in this context that the “gene-centered” theory
of Richard Dawkins was conceived. DNA was considered to be at the core
of life, having the sole function of continuous replication (the replicator)
and using the other parts of the organism (metabolism, body, brain, etc.)
as the vehicle to carry out this mission. Evolution then becomes a matter
of competition for abundance among genes (or segments of DNA) — a
concept called the “selfish gene theory.”3,
This “DNA-centered” view of life enjoyed popularity for decades
but has gradually lost its appeal (to be elaborated in Chapter 3: Self and
the Beginning of Life). New evidence shows that evolution is a multi-
dimensional business, and DNA is just one of the dimensions.^5 A new
way of thinking places the unit of natural selection back to the organ-
ismic level, and considers the organism as a complex system in which
the activity of the whole is greater than the sum of the parts. DNA is
reduced to a tool for the perpetuation of this system. The current book
is an offshoot of this line of thinking, and I call this “system of life” self.
Besides, my definition of “self” permits me to cover both the observable