This is part of a series of posts on the means by which life came about within Christianity. See other posts on the topic here.
Last time I wrote about theistic evolution I mentioned I was quite excited to get into some the scientific side of the debate. I delved into that a bit with my first post on old earth creationism as well as in my post on young earth creationism. While I think that perhaps the biggest problem with theistic evolution from a Christian view is theological, I do believe it is important to examine the scientific aspect of all sides of the debate as well. Thus, I turned to Perspectives on an Evolving Creation, a work full of essays on theistic evolution, to give me the scientific aspects of theistic evolution.
Common descent is central to the notion of atheism. Often, common descent is the source of objections to the theory of evolution (Miller, 152). Common descent is the assertion that all life on earth is descended from an “unbroken series of ancestor-descendant relationships to a single ancestral life form” (Miller, 152). Perhaps the most frequent objection to this is the sparse distribution of the fossil record.
Miller argues that the fossil record, rather than being incapable of demonstrating common descent, provides “persuasive evidence for macroevolutionary change and common descent” (153). He quickly qualifies this statement, pointing out that most often people either assert that the fossil record is so sparse that nothing can be demonstrated by it or that it is so complete that all details can be brought to light.
Miller then points out the vast problems with trying to fill in a fossil record which, according to evolutionary theory, covers hundreds of millions of years. Some of these problems include the infrequent fossilization of soft bodied or thin-shelled organisms, environmental factors such as weather, scavengers, or water levels, erosion, irregular sedimentation, etc. (154-156).
Transitional forms also encounter the problems of classification. The way species are categorized can directly affect whether a species is seen as a transitional form. “The grouping of organisms in a classification scheme does more than describe nature: it also interprets it” (158). Miller goes on to discuss two types of classification: the Linnean and cladistic classification. Linnean classification views species as types. One individual is seen as the ideal “archetype” of the species, while all others are compared to this “archetype” and then seen as types or offshoots of this individual. This, argues Miller, “exclude[s] transition[al fossils] by definition” (158, emphasis his). Cladistic classification, by contrast, assumes an evolutionary scheme and places animals into overarching schemes based on such assumptions. Thus, species may not be grouped so much by common characteristics as they are grouped by characteristics seen as having a common ancestor (159).
Interestingly, this section seems to echo one of the statements I remember from a talk on Young Earth Creation I listened to on campus, in which the speaker stated that often scientists can look at the same evidence and come up with completely different interpretations–even though the evidence is the same. I’ll be keeping this in mind in my future interactions with the varied positions in this dialogue. Here, it seems the cladistic classification is preferred, though one may ask whether this is because one wants to presuppose evolution and move from there, or if it is because the fossil record points more readily towards evolution. Did the evidence lead to the classification or did the classification lead to the evidence?
Transitional forms often are attached to misconceptions. Miller warns against assuming that such a form would appear as a logical step from one type of animal to the next. Rather, he states that “Such forms will be unlike anything living today”. This is because “transitional forms are found by moving down the tree of life into the past, not trying to jump from limb to limb” (161). Thus, when thinking of transitional forms, rather than seeing a kind of orthogenesis (one step at a time) that would suggest, perhaps, species 1 => species 2 => species 3, the view should be a branching phylogeny which looks more like a tree than a straight line. Thus, transitional fossils could be radically different from the species to which they gave rise (163).
After this point in his chapter, Miller goes into some examples of just these types of transitions viewed in the fossil record. His examples include reptile-to-mammal evolution, a land creature-to-whale evolution, horses, tapers, rhinos, etc. having a common ancestor, and others (164-180). Due to such transitional evidence in the fossil record, Miller concludes that “transitional fossil sequences between higher taxonomic groups are a common feature of the fossil record” (180).
One may question Miller on a number of points in this chapter. The different classification systems is one presupposition that must be made. Another objection that came to my mind as I was reading was the definition of transitional fossil. Again, it seems as though the definition may be changed to fit the theory, rather than the theory changed to fit the definition or the evidence. Why couldn’t it be that transitional fossils are just what intuition suggests, and there really aren’t too many? Rather, the assumption seems to be that other fossils may be used for the transitions. Why make such an assumption? Is there any reason to push the transitional definition to the usage Miller is endorsing? I don’t know.
I enjoyed Miller’s chapter greatly. It is always nice to get a breath of fresh air amidst my readings of analytic philosophy or epistemology. I have enjoyed this series greatly, and I can’t wait to continue.
Finally, in closing, I would like to note two things again. The first is my stance on this whole debate: I believe the Bible is the inerrant Word of God, I believe that God did and does directly intervene in creation and the universe, and I believe that God has been and always will be the creator and sustainer of the universe. Thus, I am biased, just as anyone who approaches such questions is. Second, I have noted before that this series is meant to be for the in-house Christian debate on these matters. I’ve had a number of caustic comments thrown my way from those uninterested in such a debate. I welcome non-Christians to the discussion, but only if they can participate in a civil manner.
Miller, Keith. “Common Descent, Transitional Forms, and the Fossil Record.” Edited Keith Miller. Perspectives on an Evolving Creation. Wm. B.Eerdman’s. 2003.
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