  The theory of interaction-based evolution argues that, at the most basic
level of analysis, there is a third alternative for how adaptive evolution
works besides a) accidental mutation and natural selection and b) Lamarckism,
namely, c) information provided by natural selection on the fit between the
organism and its environment is absorbed by non-accidental mutation. This
non-accidental mutation is non-Lamarckian yet useful for evolution, and is due
to evolved and continually evolving mutational mechanisms operating in the germ
cells. However, this theory has left a fundamental problem open: If mutational
mechanisms are not Lamarckian---if they are not "aware" of the environment and
the macroscale phenotype---then how could heritable novelty be due to anything
other than accidental mutation? This paper aims to address this question by
arguing the following. Mutational mechanisms can be broadly construed as
enacting local simplification operations on the DNA in germ cells, along with
gene duplication. The joint action of these mutational operations and natural
selection provides simplification under performance pressure. This joint action
creates from preexisting biological interactions new elements that have the
inherent capacity to come together into unexpected useful interactions with
other such elements, thus explaining nature's tendency for cooption. Novelty
thus arises not from a local genetic accident but from gradual network-level
evolution. Many empirical observations are explained from this perspective,
from cooption and gene fusion at the molecular level, to the evolution of
behavior and instinct at the organismal level. Finally, the nature of
mutational mechanisms and the need to study them in detail are described, and a
connection is drawn between evolution and learning.
