On the Origins of New Forms of Life: Introduction
On the Origins of New Forms of Life: Introduction

On the Origins of New Forms of Life: Introduction

How does evolution occur? — That is, what natural processes bring new types of organisms into being? Expressed more technically, one might ask, what are the genetic processes that have produced the various forms that scientists recognize and assign scientific names? This is the question considered in the analysis of evolutionary theory presented on this website (View Highlight)

I readily admit that many of the claims made by my fellow evolutionary biologists are in fact correct and entirely reasonable. But some are inconsistent with fact and, in my opinion, the corresponding aspects of evolutionary theory need adjustment. (View Highlight)

As Darwin's most eloquent proponent, T. H. Huxley, once said, "Every great truth begins as heresy and ends as superstition." In the case of evolutionary theory, Huxley appears to have been right. (View Highlight)

ccording to this alternative view, which I call stabilization theory, certain genetic processes known to disrupt the normal reproductive cycle are the typical source of new types of organisms (a variety of these stabilization processes are described in Section 4 of this website). (View Highlight)

The most common name for this theory is neo-Darwinism, although it also is known as the modern synthesis (often capitalized), or the synthetic theory. It supposes that in the course of evolution the typical new form arises from a preexisting form via the gradual accumulation of distinctive traits. In other words, the new characteristics are acquired in sequence over time, not all at once. Most of these traits are assumed to be advantageous to reproduction and therefore to accumulate under the influence of natural selection. As Darwin puts it in the Origin of Species, (View Highlight)

They are naturally selected, just as a breeder artificially selects particular traits. Thus, under this view of the evolutionary process, traits favoring survival and successful reproduction will tend to accumulate over time and bring about changes in the affected form. (View Highlight)

The idea of an accumulation of differences resulting in gradual divergence (and ultimately in the production of new types of organisms) is axiomatic in neo-Darwinian theory, and is therefore the orthodox account of evolution (View Highlight)

In his book, The Great Chain of Being, Arthur Lovejoy comments that there are implicit or incompletely explicit assumptions, or more or less unconscious mental habits, operating in the thought of an individual or a generation. (View Highlight)

Hybridization plays a much more important, and a different, role in stabilization theory than it does in neo-Darwinian theory. The word hybrid has been defined in various ways, but a particular definition is well suited to stabilization theory: If two populations are consistently distinct with respect to one or more characters, and if a descendant of matings between those populations is discernibly mixed with respect to those characters, then that individual is a hybrid and any process producing such individuals is hybridization. (View Highlight)

Although hybrids are often less fertile than either of their parents, the degree of fertility varies greatly from one hybrid individual to another, and many are fully capable of producing offspring (View Highlight)

Most, but not all, of the evolutionary processes posited by stabilization theory involve hybridization, which is the topic of Section 2 (the evolutionary discussion on this website is broken up topically into sections) (View Highlight)

Because the processes it emphasizes produce new types of organisms in a relatively rapid and abrupt manner, stabilization theory undermines a primary tenet of neo-Darwinian theory — the claim that evolution is typically a process involving the gradual accumulation of differences within an evolving population. (View Highlight)

It merely claims they are relevant only within a restricted domain, specifically identified in Section 3. It does, however, claim that stabilization processes are the main source of new types of organisms. (View Highlight)

Moreover, the expected pattern of evolutionary change produced by such processes matches the pattern of change actually observed in the fossil record (Section 6). These processes are also far better documented than many of the mechanisms described in neo-Darwinian theory. (View Highlight)