water in an egalitarian display
of terminal dodge ball. The crocodiles lying in wait under the water can’t tell
if the wildebeest they are about to drag beneath the surface in a death roll
are healthy, weak, a mother or among the newborn young. So, our conceptions of
the laws of nature resulting in the culling of the old or the weak from the
herd fall by the wayside. In fact, some arbitrary few are sacrificed and the
herd benefits.
How does this
fit into the framework of selection? Well, we have to consider the possibility
that a threat can be global to the group as well as to an individual. The
sacrificial trait can grow in order to minimize the global threat. By
developing the sacrificial trait, wildebeest are able to survive as a group. Of
course, we haven’t yet explained why the wildebeest want to be in a group.
Nevertheless, the group by surviving, in turn allows many of them to survive
individually. This is the core and the enabler of multi-level selection. Thus,
we suggest that multi-level selection might well be observed when applied to
groups of individuals. Under threat, the groups are under pressure, as well as
the individuals in each group. Individuals will be faced with the conflicting
demands made on them by both group and individual threats. Of course, we must
remember that in some instances the impetus for grouping fails. The Mayans we
considered in the first chapter apparently crossed this boundary; the wildebeest
didn’t.
As another
example, let’s consider a military anecdote; a company constituted of four
platoons, facing an overwhelming enemy. The company commander may decide that
the only way to save most of the force is to sacrifice one platoon to fix the
enemy in place, thereby limiting the enemy’s mobility while the other friendly
platoons withdraw. One might think that the soldiers of the platoon left behind
would have different personal preferences. However, some mechanism causes them
to orient their actions toward the group’s benefit rather than their own.
Interaction between the selective pressures will define the situation, all
under the prism of evolution. The interesting question remains; in the case of
selection favoring a group, what is the feedback mechanism that speaks to the
continuation of the group? We’ll consider this in greater detail in Chapter 5.
Perhaps one of
the more difficult aspects of evolutionary processes for us to assimilate is
the statistical nature of their being. It is the classical situation of forests
and trees. When we’re immersed in the individual characteristics of a tree, it
requires some rather careful analysis to perceive the statistical nature of the
forest. Our rather natural inclination is to attempt to see and appreciate the
dynamics of evolutionary change in terms of our everyday experience; through
anecdotal example if you will. Indeed, we’ve already suggested that very low
probability events are indistinguishable from miracles. Seen in this light, it
is difficult to fathom the prospect of evolutionary change that leads from the
most simple, single cell life to the magnificent logical complexity of the
human mind or the subtle mechanical complexity of the human eye. To make this
leap through a single mutational event seems too fantastic to believe, and, in
fact, it is. On the other hand, if we can accept the results of statistical
processes involving very large numbers confronted with lots of opportunity for
small changes in an incredibly large number of instances spread over an
incomprehensible amount of time, then evolutionary change seems much more
palatable.
At the beginning
of this chapter, we set out to consider the area of overlap of the mechanisms
of evolutionary change of first, organic life and then, of computers. At this
point, we’ve made our overview examination of the mechanisms of life; now let’s
look at the mechanisms of computers.
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