Replaying the Tape of Life and Finding a Chemical Sequence


(system) #1
What does the Periodic Table have to do with the meaning of life?
This is a companion discussion topic for the original entry at https://biologos.org/blogs/kathryn-applegate-endless-forms-most-beautiful/replaying-the-tape-of-life-and-finding-a-chemical-sequence

(Larry Bunce) #3

I don’t recall ever seeing a discussion about evolution that mentioned chemistry. Arguments against life ever getting started by natural means seem to assume that elements combine in random fashion, rather than taking into account the fact that elements are attracted to each other in specific ways. Carbon and hydrogen are hard to keep separate, and readily form long chain molecules that are the basis of life. That fact of chemistry alone reduces the role of chance in the origin of life by many orders of magnitude.

Chemistry was not my favorite subject in high school, but I still find it an interesting subject to read about. I have always wondered if the reason some living organisms remain essentially unchanged for millions of years, while others have changed greatly in less time is the result of the DNA configuration of these organisms being more avd less stable chemically. I remember a report of an experiment done in the desert during the 50s with a fenced off land area exposed to high doses of radiation. The reptiles and insects showed no ill effects, but the mammals became deformed and died out. Living at the upper end of the evolutionary scale is not an unmixed blessing.


#4

You really do need a foundation in chemistry to study the life sciences these days.


(Roger A. Sawtelle) #5

Our stance does not question that this description of the random origin of species is correct, we believe it is, but we consider that the species-embracing chemotypes and their divisions, which include very large groups of species in well-separated classes of organisms, have developed differently in an inevitable logical sequence forced by equilibrium thermodynamic environmental, and largely kinetically controlled life chemistry. (The Chemistry of Evolution, p. 307) - See more at: http://biologos.org/blogs/kathryn-applegate-endless-forms-most-beautiful/replaying-the-tape-of-life-and-finding-a-chemical-sequence#sthash.1S2qgOSC.dpuf

I have a serious problem with this post. The problem is that it fails to seriously question the standard understanding of evolutionary change as witnessed by Gould’s quote, while citing strong scientific evidence that this understanding is wrong.

The random origin of species is not correct, and I challenge anyone to prove it is correct. Why do we seek scientific evidence if we are unwilling to follow through and see where it leads us, even though we might not want to go there.

Gould and Williams their belief in a random origin of species in a false, but common misunderstanding of Darwin. Darwin stated that there is two distinct aspects of Evolution, Variation, and Natural Selection. Variation is random, but Natural Selection is determinate, so evolution is both random and determinate, but in the end Natural Selection is decisive, do it is best described as determinate.

This is not a philosophical question, this is a scientific question which needs to be addressed scientifically. When we fail to do so, we deserve to lose debates with non-believers. We need to trust God that God knew what God was doing when God created evolution fo0r the purpose of filling the earth with life and creating human beings.

Gould and Dawkins version of random, purposeless evolution has been disproven by Williams and others. It is about time we let the world know this.


(Ben McFarland) #6

Roger, This post doesn’t aim to establish a random origin of species, but to suggest that it may be beside the main point. The Gould vs. Williams debate shows that two scientists who agree on the random origin of species nonetheless disagree on the level of predictability at higher levels: what Williams calls the “chemotype” level. What if chemotypes are predictable while species are not? Predictable chemotypes that predictably fill the earth fulfill God’s purpose (and then there’s the issue of if intelligent life is predictable or not from that, Williams says yes while Gould says no), so Williams’s view of destiny seems to be very close to what you say in your comment, just at a different level than the level of individual species (not to mention, how are species defined? Is a broad definition adequate, and if so, could “chemotypes” be an acceptable substitute for species?). There’s much more to say about this, but the different levels of predictability are what I write about in my book at length, which is my effort to let the world know about this. I agree with your last sentence and I’ve tried to do something about it by writing about it. Yours, Ben


(Roger A. Sawtelle) #7

@benmc

Thank you so much for your response.

I disagree with the above statement. The question about the random origin of the species raises serious disagreement on this blog.

Now what you might mean (and this is always a problem for me) is that random means only not predetermined In other words I would agree that evolution is not predetermined, meaning that the end product, whatever that means in this context, is not predetermined from the beginning. On the other hand I would sway that that it is determinate meaning that it is set up to favor the evolut6ion of an intelligent being, as the Anthropic Principle seems to imply.

One could easily ask, Could humans have evolved if evolution would not have favored intelligence? If evolution through Natural Selection favors one allele over another, it is being determinate as opposed to random.

Now this is part of the case that I see against random origin. The other point that I made was concerning the nature of Natural Selection which is determinate as explained above. This is a “pet peeve,” but also is part of the “evolution problem,” which is bedeviling our understanding of our world and ourselves today. It is much more serious than trying convert some evangelicals to a science friendly point of view.

I have written a book also, Darwin’s Myth, about Natural Selection. I well send it to you if you are interested.


(Ben McFarland) #8

Yes, I’d be interested to see your book, Roger. I’m trying to get at the nature of the disagreement here because I’m agreeing with several of your statements. One may be the practical result of randomness. I don’t think random means only not predetermined, in fact, I think random makes a population predetermined in a sense. Random means a probability of distributions so that events that are individually unknowable* produce a predictable distribution. Random molecular motion produces a predictable reaction because of the forms/shapes set by the periodic table, for example. This may be my chemical training coming through, so one of the issues may be exactly what I mean by random. But I think it has a definite place and that you can see its effect on things like genome architecture.

(* Also note, unknowable by us means nothing about whether those events are knowable to God)

I think that Williams’s sense of something “funny” (which is similar to the anthropic principle) works regardless of how species originate, because it is more about natural selection than the genetic variation that selection works upon, which fits with your distinctions between selection and variation. The chemical sequence Williams talks about is set by the periodic table and results in a changing environment that selects for new things as time goes by in a predictable sequence. I think there’s both random and non-random components to the genetic changes that the environment selects, and that the fact that evolution moved at different speeds in response to the environment is one indication that it’s not entirely random.

But the main point to me is, if we look at that environment, it provides a predictable environmental change that made selection occur in a predictable sequence. To me, that’s a great example of how chaos at one level is constrained by predictability at another level – like water molecules moving randomly, yet constrained by the banks of the river in which they flow. It doesn’t bother me that the origin of molecular motion is random energy, because that random energy is constrained by chemical laws and physical laws etc. etc. That’s a pretty exact analogy for how random genetic variation can be constrained by the environment.

Again, the leap from that to “the universe must produce intelligence” is a big one, but I’m with Williams in that I find the ordered sequence of chemical events in natural history, especially with respect to the chemical power of oxygen providing the power for all these changes to take place (and changing both rocks and life) to be a “funny” thing that is a breath of fresh air in contrast to the emphasis on randomness taken by Gould and Dawkins, who I think focus on the random trees and miss the order of the forest. I think we agree on that criticism of Gould and Dawkins too – but my favorite argument against their emphasis is to emphasize the other levels that we can predict (and have predicted correctly in the case of Williams).

Hope this makes some sense, it’s late on a Friday for me so I may have made some mistakes (as always) – Yours, Ben


(GJDS) #9

I would be interested in knowing more on what is meant by chemotypes - I am familiar with the periodic table and how elements are grouped, but I have not heard chemists refer to chemotypes.

On origins, we need to be reminded that most of the chemistry we may invoke can be dealt with by equilibrium computations and chemical kinetics computations. If we commence with a “ball of plasma” cooling into planet earth, all gaseous elements will reach their equilibrium distribution (stable compounds such as CO2 and H2O). It is unlikely that alkane (C-H) compounds would form, as Oxygen would preferentially react with C and H. So we need to know the composition (or amounts) of elements present before we can talk of subsequent chemistry once the earth has cooled. The notion of a planet depleted of oxygen is now accepted by scientist - thus the need for chemistry that would produce oxygen before life as we observe may be contemplated.

The topic is lengthy and complicated and I cannot go in more detail, but we should remember that even atheists are skeptical of many notions put forward regarding the primordial planet called earth. Subsequent notions of how life began are more in keeping with fiction.


(Roger A. Sawtelle) #10

[quote=“benmc, post:8, topic:5075”]
I think random makes a population predetermined in a sense. Random means a probability of distributions so that events that are individually unknowable* produce a predictable distribution. Random molecular motion produces a predictable reaction because of the forms/shapes set by the periodic table, for example. This may be my chemical training coming through, so one of the issues may be exactly what I mean by random. But I think it has a definite place and that you can see its effect on things like genome architecture.

(* Also note, unknowable by us means nothing about whether those events are knowable to God)
[/quote]

Ben,

What you are saying demonstrates the importance of making the distinction between random Variation and determinate Natural Selection. When you say that random molecular motion produces predictable because of the forms/shapes set by the periodic table, aren’t you saying that atoms of hydrogen and oxygen interact in a random manner to create water?

While this is definitely true, I would argue that it is not the random movement of the molecules that produce this result, but the form of atoms, which makes this union possible and of course the energy in the form of heat which is the literal spark for this event. It is not “random” that H2 01 is water. That is determined by the structure of the universe. However we can say that water is created randomly by the union of random atoms, but we cannot say that the process is random, because water is not H2 N or some other random combination.

_Mutations can be caused by random errors in DNA replication or repair, or by chemical or radiation damage. Most times, mutations are either harmful or neutral, but in rare instances, a mutation might prove beneficial to the organism. If so, it will become more prevalent in the next generation and spread throughout the population.

In this way, natural selection guides the evolutionary process, preserving and adding up the beneficial mutations and rejecting the bad ones. “Mutations are random, but selection for them is not random,” Pobiner said.
- See more at: http://www.livescience.com/474-controversy-evolution-works.html#sthash.Rz0LaGlM.dpuf

In the same way Variation produces a number of possible variations, large and small. Natural Selection sorts out the good, the bas, and the neutral. The way it does so is by trial and error. The positive result is adaption to the environmental niche. The negative result is the failure to adapt to as changing environmental niche. Thus variations are selected to adapt. They either work or don’t and are self fulfilling. This means that the changing environment guides and directs evolution, which is how God determined the creation of human beings, not by using radiation somehow to produce the right DNA.

So the question is not whether it is the process random or not, because it does have random aspects. The question is what are the random and determinate aspects of evolution and HOW they work together to produce a given result. This process give me an understanding which is compatible with science and clearly compatible with God’s guidance a direction of the creation of humanity.

Clearly chemistry is part of the environment. I have also noticed that many people see evolution as a vertical process, while chemistry and ecology is more of a horizon process. I see life as with both vertical and horizon dimensions, which is part of what makes it triune.

I do not think Dawkins wants to see the order of the forest. After all he has made his fortune on denying the designed order in the universe.


#11

I don’t think chemotype is a word from the discipline of chemistry. According to the article, Williams is grouping species by the chemicals they eat and excrete, and calling each group a “chemotype.”

Academic Search Premier had nothing on the subject, but Wikipedia had a definition. Go figure.


(Ben McFarland) #12

RJP Williams coined the term “chemotype,” and the book of his that most goes into its definition and sequence is The Chemistry of Evolution (2006). I mention it in A World from Dust at crucial points but don’t refer to it by name more than I have to. The idea runs behind the narrative. As for the other issues, part of the chemical story is how oxygen got locked up in the earth and then was released by photosynthesis (among other processes!). The origin of life chapter is deliberately more speculative because, of course, that’s perhaps the most challenging of all steps, and I only present it as 7 clues, but each clue backed up with lab experiments. Williams also talks about chemotypes in some of his journal articles and reviews, and that may be easier to find online than his book. (Of course, I’ve tried to make my own book easy to find too … :slight_smile: )


(GJDS) #13

Thanks for the reference - I do not have the time to read the book by Williams, but I have his paper, “A chemical systems approach to evolution” in Dalton Tr and I will read it carefully - from an initial look, I have the impression that he has commenced with the premise that life commenced within the evolutionary paradigm and he now seeks to classify the contributions of various elements to the energetics of bio-species. If my impression is correct, I would think this approach bypasses the difficult questions - nonetheless it is an interesting outlook and I will read his paper(s) as time permits.