Evolution of Complexity. Molecular Aspects of Preassembly

Abstract

An extension of neo-Darwinism, termed preassembly, states that genetic material required for many complex traits, such as echolocation, was present long before emergence of the traits. Assembly of genes and gene segments had occurred over protracted time-periods within large libraries of non-coding genes. Epigenetic factors ultimately promoted transfers from noncoding to coding genes, leading to abrupt formation of the trait via de novo genes. This preassembly model explains many observations that to this present day still puzzle biologists: formation of super-complexity in the absence of multiple fossil precursors, as with bat echolocation and flowering plants; major genetic and physical alterations occurring in just a few thousand years, as with housecat evolution; lack of precursors preceding lush periods of species expansion, as in the Cambrian explosion; and evolution of costly traits that exceed their need during evolutionary times, as with human intelligence. What follows in this paper is a mechanism that is not meant to supplant neo-Darwinism; instead, preassembly aims to supplement current ideas when complexity issues leave them struggling.

Keywords: complexity; echolocation; epigenetics; evolution theory; non-coding genes; preassembly.

Figure 1

In this recording, the pallid bat (Antrozous pallidus) makes four echolocation calls followed by social calls. The spectrogram above (kHz vs. msec) is a graphic representation of the sounds. Credit: Katy Warner, Colorado State Univ.

Figure 2

Pictures representing bat echolocation, flowering plants, human intelligence, trilobites, and cat domesticity whose evolutions all defy the neo-Darwinian model.