Biological Evolution: What is being debated (again)

Evolution has several meanings. The meanings of evolution, from Darwinism, Design and Public Education:

1. Change over time; history of nature; any sequence of events in nature
2. Changes in the frequencies of alleles in the gene pool of a population
3. Limited common descent: the idea that particular groups of organisms have descended from a common ancestor.
4. The mechanisms responsible for the change required to produce limited descent with modification, chiefly natural selection acting on random variations or mutations.
5. Universal common descent: the idea that all organisms have descended from a single common ancestor.
6. “Blind watchmaker” thesis: the idea that all organisms have descended from common ancestors solely through an unguided, unintelligent, purposeless, material processes such as natural selection acting on random variations or mutations; that the mechanisms of natural selection, random variation and mutation, and perhaps other similarly naturalistic mechanisms, are completely sufficient to account for the appearance of design in living organisms.


The debate isn't as black & white as saying it is evo #6 against IDists, Creationists and theistic evolutionists. However it is obvious that evo #6 is what is being debated.

(Theistic evolutionists are a different breed. They don't seem to acknowledge that evo #6 is what is being taught in our public school system. And therefore don't appear to understand the issue. The TE's I have debated with tell me that humans were an intended outcome of the evolutionary process, which is OK for evo #5 but defies evo #6. IOW TE's are closet IDists.)

Creationists go with 1-4 (above), with the change in 4 being built-in responses to environmental cues or organism direction as the primary mechanism, for allele frequency change, culled by various selection processes (as well as random effects/ events/ choice of not to mate/ unable to find a mate). The secondary mechanism would be random variations or mutations culled by similar processes. IOW life’s diversity evolved from the originally Created Kind, humans included. Science should therefore be the tool/ process with which we determine what those kinds were. Just as Carolus Linneaus attempted to do some 200 years ago.

see also The Current Status of Baraminology


With Creation vs. "Evolution #6" the 4 main debating points are clear:

1) The starting point of the evolutionary process. (What was (were) the founding population(s)?)
2) The phenotypic & morphological plasticity allowed/ extent the evolutionary process can take a population (do limits exist?).
3) The apparent direction the evolutionary process took to form the history of life. (ie from "simpler" bacteria-like organisms to complex metazoans)
4) The mechanism for the evolutionary process.

With ID vs. Evo #6 it is mainly about the mechanism- IDists go with evolution 1-5, with the Creation change to 4 plus the following caveat in 5: Life’s diversity was brought about via the intent of a design. The initial conditions, parameters, resources and goal was pre-programmed as part of an evolutionary algorithm designed to bring forth complex metazoans, as well as leave behind the more “simple” viruses, prokaryotes and single-celled eukaryotes.

IDists understand that if life didn't arise from non-living matter via some blind watchmaker-type process, there is no reason to infer its subsequent diversity arose soley due to those type of processes (point 1 up top).

What does the data say? Well there isn't any data that demonstrates bacteria can "evolve" into anything but bacteria. Therefore anyone who accepts evolution 5 or 6 has some splaining to do. Preferably splainations with scientific merit.

Throwing time at an issue does not splain anything:

Extrapolating from small change

If one desires to extrapolate small changes into large changes by simply adding time, one requires independent evidence to justify this move. The problem is that we really don't know how evolution occurs. And when talking about the evolution of the mammalian middle ear bones, we should not forget that we are still basically in the dark in trying to explain how both a mammalian and reptilian zygote actually develops the middle ear and jaw bones, respectively. Without this knowledge, attempts to explain such a transition as a function of a series of small, incremental changes stretched across time are rooted in ignorance. That is, we don't truly understand neither the process of development nor the process of evolution and without such knowledge, there is no reason to think we are on safe ground when employing (1).

Attempts to justify this move by appealing to the use of (1) in astronomy and geology fail because biotic complexity differs in both structure and formation.

One may assume (1) to explain evolutionary change as a working hypothesis, but we should keep in mind that large changes in evolution are basically a "black box" and a series of small incremental changes may play only a trivial, fine-tuning role in any transition (there is no evidence to think otherwise). What's more, bacteria, as the predominant life forms on this planet, which have experience the most evolution of all life forms, tell us clearly that (1) need not apply to biological evolution.

In the end, appeals to small change + deep time are embraced merely as a matter of convenience, as it happens to be the primary way we can think about evolution at a time when we are just starting to come to grips with it. As we begin to better understand the process of evolution, I predict (1) will one day be viewed as a quaint understanding that served mostly to highlight just how much we didn't understand evolution.

Anyone who sides with universal common descent needs to account for the physiological and anatomical differences observed. Genetic similarities can also be explained by convergence and a common design. Therefore if genetic similarities are all UCD has then it is clear that common design and convergence are as "scientific" as UCD.

However Father Time, Mother Nature and some still unknown natural process does make for an interesting trinity...