In the book "Why Evolution Is True" the author states: --- it really consists of six components: evolution, gradualism, speciation, common ancestry, natural selection, and nonselective mechanisms of evolutionary change. (p-3)[emphasis supplied].
Darwin's theory that all of life was the product of evolution, and that the evolutionary process was driven largely by natural selection, has been called the greatest idea that anyone ever had. (p-ivi).
"— this volume gives a succinct summary of why modern science recognizes evolution as true." (p-xiv)
These viewpoints are addressed below in terms of their "materialistic" implications
The book's Figure 1 (below left) is a graphic depictions of Darwin's hypothesis of Descent From A Common Ancestor, and is typical of the science's universal expression of the progressive development of animal forms from the proposed common ancestor --- the divergent animal forms depending on "species splitting" at, for example, a common ancestor designated as node X, a single ancestral species, that split into two descendant species.
The right-hand figure is the book's Figure 1 that has been edited to illustrate (sequences of blurred images) where, following the split, each species underwent development.
In this blog, the X points are considered "starting points" representing the first documented appearance of a body plan sufficient to be recognized as exhibiting traits recognized as "novelties".
This blog focuses on one fundamental question: What is implied when the traits of a described body plan are perceived as having "evolved" from body-plan characteristics that presumably existed in a "most-recent-common ancestor" or in "the last universal common ancestor?" This ideology is fundamentally based on "materialism" which maintains that the origin and development of organism characteristics was/is due to natural physical/chemical processes. This blog's purpose is to argue that the field's common ancestor concept involves recourse to organism origins whose materialstic processes cannot be rationally described and are essentially unknown. If so, then non-materialistic origins and processes cannot be objectively ruled out. The following text sections contain summaries of modules that address various biological evolution concepts that are directly or indirectly related to the materialistic view of the common ancestor hypothesis as implied in the foregoing figures.