Patterns in the Fossil Record

Science Daily has a post on research about patterns in the fossil record that comes out of the Santa Fe Institute.  They write:

Throughout life's history on earth, biological diversity has gone through ebbs and flows -- periods of rapid evolution and of dramatic extinctions. We know this, at least in part, through the fossil record of marine invertebrates left behind since the Cambrian period. Remarkably, extreme events of diversification and extinction happen more frequently than a typical, Gaussian, distribution would predict. Instead of the typical bell-shaped curve, the fossil record shows a fat-tailed distribution, with extreme, outlier, events occurring with higher-than-expected probability.

While scientists have long known about this unusual pattern in the fossil record, they have struggled to explain it. 

Now, at last, there is something of an answer.

“Within a lineage of closely related organisms, there should be a conserved evolutionary dynamic. Between different lineages, that dynamic can change,” says [Andy] Rominger. “That is, within clades, related organisms tend to find an effective adaptive strategy and never stray too far. But between these clade-specific fitness peaks are valleys of metaphorically uninhabited space. It turns out, just invoking that simple idea, with some very simple mathematics, described the patterns in the fossil record very well.”

Sometimes, it just pays to rethink something from a different angle. This may open up doors to understanding other patterns in the fossil record.

New BioLogos Post on Hominin Taxonomic Variability in the Early to Middle Pliocene

I have a new post on hominin taxonomic variability in the early to middle Pliocene in light of the new Australopithecus deriyemeda find from Burtele that establishes that at least two very different hominin adaptations were occurring at the same time, around three to four million years ago.  There is a lengthy intro by Brad Kramer, the content editor, warning people that there are “technical terms” and that the article is a “black diamond” article, which suggests that they keep a glossary or dictionary handy.

It seems that, when I wasn't paying attention, I  turned into a cladist.  This comes from reading too many papers on Pseudosuchia and Avemetarsalia and trying to explain evolutionary theory to people.

The one thing that is missing from Brad's intro is an effort to explain how this fits into the grand Christian scheme of things, which would probably not have been appropriate in this setting, in any event, since it is a separate, but related topic.  I sometimes suffer from a slightly reductionist mindset in that I take these discoveries to be self-evident and just another part of God's creation (Brad does allude to that) without really taking the time to reflect on how this information comes across to your average Christian who likely is not familiar with it and how it might challenge their scriptural interpretations.  To this end, I probably need to make a better effort to work that in, somehow. 

Evolution and Creationism: A Continuum or a Taxonomy?

Steve Martin over at An Evangelical Dialogue on Evolution has some thoughts about the NCSE Creation—Evolution "Continuum." This comes originally from an article written in the late 1990s by Eugenie Scott called Antievolution and Creationism in the United States¹The NCSE has modified it over time to give ID more prominence. Dr. Scott views the continuum as being a beneficial heuristic in getting students of all ages to understand how complex the controversy really is. Steve is not convinced:

Pointing out these intermediary positions is a good way to help people understand that there is some complexity to this discussion. However, it is my view that this model may actually be counter-productive, particularly when promoting evolution in various faith communities. I believe that those of us that support the coexistence and coherence of evolution and an Evangelical expression of the Christian faith need a much better model if we are to make any progress on this issue within the Evangelical community.

The problem relates to how the continuum is put together in the first place. As Steve points out, Scott assumes a priori that if you are on the bottom of the continuum at the evolution end, you have no faith in God, whereas if you are at the top, you interpret the Bible literally. I am reminded by what Jerry Coyne had to say in his review of Ken Miller's book Only a Theory:

The reason that many liberal theologians see religion and evolution as harmonious is that they espouse a theology not only alien but unrecognizable as religion to most Americans.

Steve and others, including myself, would disagree. This is why TEs walk a very thin line. We are castigated by the YEC crowd as having fatally compromised our faith in the acceptance of an old earth and evolutionary theory and yet we are pilloried by the philosophical naturalism crowd who assume we either have to check in our brains at the door when we go to church or that we don't think the Bible is the word of God (Jesus Seminar, anyone?). Steve also suggests that the scientific criterium is incorrect as well, in that it assumes an inverse of the religious criterium. There are other things. It assumes that there is a difference between Theistic evolution and evoutionary creationism, a difference that has certainly never been made clear to me. Also, placing evolutionary creationism right smack against progressive creationism is sort of like sitting in row 6 on an airplane where smoking is permitted in rows 1-5.

In response to the continuum, Steve has devised a new model that sees three positions

1. theistic evolution
2. non-evolutionary creation
   
3. naturalistic, or materialistic evolution

This is reductionist almost to the extreme. Several benefits and disadvantages become evident. The obvious benefit to those of us that are TEs is that we can take our Bibles and walk toward the back of the plane, away from the non-evolutionary rows. The problem is that the non-evolutionary positions now take up to row 22! Mixing my metaphors here, this is truly "big tent" creationism. The non-evolutionary creation sphere includes everybody from Reasons to Believe, an old earth non-evolutionary site to the folks at fixedearth.com who truly, honestly believe that the earth is fixed and is in the center of the universe (Or maybe I've been had and it is like the Dihydrogen Monoxide Research Division). In that mix is the Discovery Institute and the ICR who are allies in much the same way that Churchill and Stalin were allies during the Second World War. I posit that the question can be looked at in a different way.

Being a biologist by training, I would suggest that a taxonomic tree is, perhaps, more appropriate for this question. It might look something like this:


Here, those who espouse the YEC viewpoint and those that are TEs can be traced back to a "common ancestor," belief in God. The disadvantage of this model is that it is subject to pigeon-holing people and has, currently, no place for agnostics, although in practice, agnostics split out to the right at the very top. I do not know of a single agnostic that accepts a young earth or progressive creationism. Its strength is that it does show elements of commonality and distinction (plesiomorphic and apomorphic traits, if you will). In this case, acceptance of evolution is convergent in both the "Yes" and "No" camp from the "belief in God" node. Help! I'm starting to sound like a cladist!!

No model will be completely satisfactory and this one has its problems, I am sure. I completely agree with Steve that Eugenie Scott's diagram makes unwarranted assumptions. I also think, though, that his model does not make enough distinctions between different lines of thought. This is by no means a finished product and I invite any and all discussion of this.