Primer: ‘Self-Replicating Life’

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This is Part IV in a series of four posts in which TFN Insider had university scientists analyze problematic changes the State Board of Education made to science curriculum standards for Texas public schools in 2009. This year publishers will submit — and the state board will approve or reject — instructional materials based on these flawed standards. The following entry examines the current version of Texas Essential Knowledge and Skills (9)(D), which reads as follows:

(9)  Science concepts. The student knows the significance of various molecules involved in metabolic processes and energy conversions that occur in living organisms. The student is expected to:

(D)  analyze and evaluate the evidence regarding formation of simple organic molecules and their organization into long complex molecules having information such as the DNA molecule for self-replicating life.

(Other entries in series: TEKS (3)(A) – All Sides of Scientific Evidence; TEKS (7)(B) – Sudden Appearance; TEKS (7)(G) – Complexity of the Cell)


Background
This standard was added to the Texas science TEKS in 2009. The amendment first appeared at the March 26, 2009, board meeting – the next-to-last day of the 18-month-long board curriculum revision process – in a proposal by Terri Leo, R-Spring.

During board debate, Don McLeroy, R-Bryan, explained that the new standard was “basically an origin of life amendment,” referencing public testimony provided previously by Ide Trotter, a well-known promoter of :intelligent design.” The amendment passed on an 8-6 vote.

The following day, at the March 27 meeting, an attempt to strike this standard failed by a 5-10 vote.


Scientific and Pedagogical Problems with Standard

By Dr. John Wise, Research Associate Professor of Biological Sciences and Adjunct Associate Professor of Biological Sciences at Southern Methodist University in Dallas

This is a clear example of the incorporation of intelligent design/creationist language into student expectations and parallels the “complexity of the cell” language found in the new TEKS (7)(G). The problematic assertion here stems mainly from the writings of Discovery Institute Fellow William Dembski. Dembski asserts that an intelligent designer must be involved in the creation of meaningful information whenever “specific complexity” is found because his own “Law of Conservation of Complex Specified Information” prevents natural selection from increasing the amount of information in a genome (see reference 1 and citations within). Dembski’s argument requires that information be complex (have a very low probability of being produced by random processes) and that it be “meaningful.” Meaningful information in the case of genetic sequences such as in DNA can be inferred to be those that increase the fitness of an organism (make it well adapted or better adapted to its environment).

Dembski’s proof of his “Law of Conservation of Complex Specified Information” has met with deep skepticism in the scientific community. Critics like Joe Felsenstein have gone so far as to term the proof “completely irrelevant” to biological-genetic informational complexity because it is “inapplicable to real biology.”1 Felsenstein points out that Dembski’s proof would require that a scrambled genome (the DNA sequences) of a well-adapted organism to be of equal fitness to an organism with an unscrambled, naturally selected genome. As Felsenstein points out, the scrambled genome would not have the same functionality, and hence the fitness of the organism with the scrambled genome would drop drastically. A large number of other criticisms of Dembski’s unsupported views on information theory have also been published (endnote 1 points out 15 such articles).

As is the case with the “complexity of the cell” argument in TEKS (7)(G), this is an example of the intelligent design/creationist tactic of pushing unsubstantiated, refuted and/or falsified hypotheses forward as a scientifically legitimate alternative to known, real and substantiated evolutionary mechanisms. Good science education in general – and the writing of good science textbooks in particular – requires that the educator and author select hypotheses that are well supported by experimental and observational evidence. And any examples utilized as a part of this instruction should focus on successful scientific analyses of natural phenomena to explain particular details about the natural world and how it works.

To allow the unsubstantiated assertion that the mechanisms of evolution cannot lead to increasing complexity in biological systems does an injustice to our children. We must use the time available in our children’s science education for presenting real evolutionary mechanisms – supported by scientific evidence – and not dilute curriculum materials with unsubstantiated musings of intelligent design creationists.


How Publishers Can Responsibly Address Standard

By Dr. Ben  Pierce, Professor of Biology and holder of the Lillian Nelson Pratt Chair at Southwestern University in Georgetown

Publishers can meet this standard by discussing the extensive research undertaken by scientists over the past 60 years that focuses on how simple organic molecules such as sugars, amino acids, and nucleotides can develop spontaneously from chemical reactions taking place in conditions present during Earth’s early history. Additional study has shown how simple organic molecules might have polymerized into long complex molecules such as DNA and RNA. For a summary of this research see Fry, 20062 and Scott and Herron, 2007.3

Much evidence suggests that early life was an RNA world.4 RNA has the ability to store genetic information and to catalyze chemical reactions, both functions that are critical to life processes.  Evidence for the important role of RNA in early evolution comes from observations that RNA can serve as catalytic molecules, the role of RNA in basic cellular processes such as replication and metabolism, RNA’s integral part in the ribosome (the protein factory of the cell) and the important role of ribonucleoside triphosphates such as ATP and GTP in basic energy conversions in the cell.

Research has shown that populations of simple RNA molecules can evolve within a test tube. Scientists have examined the possibility of the evolution of self-replicating RNA molecules in laboratory experiments. The evolution of a completely self-replicating RNA molecule has not yet been achieved, but a number of advances have been made. For example, scientists have observed the evolution within a test tube of an RNA molecule that can add up to 14 nucleotides to a growing RNA chain.5


Endnotes

1 See Felsenstein, Joe. 2007. Reports of the National Center for Science Education 27 (3-4) for a review of the arguments of W. Dembski. http://ncseweb.net/rncse/27/3-4/has-natural-selection-been-refuted-arguments-william-dembski. (Accessed on Feb 18, 2011).
2 Fry, I.  2006. “The origins of research into the origins of life.” Endeavour 30:24-28.
3 Freeman, S. and J. C. Herron.  2007.  Evolutionary Analysis, 4th Edition.  Pearson Benjamin Cummings, San Francisco.
4 Gilbert, W.  1986. “The RNA world.”  Nature 319:618.
5 Bartel, D. P. and J. W. Szostak.  1993. “Isolation of new ribozymes from a large pool of random sequences.” Science 261:1411-1418.

7 Responses to “Primer: ‘Self-Replicating Life’”

  1. Joe Lapp Says:

    This TEKS is so poorly worded that there are probably countless ways to address it. I agree that it appears to ask the students to examine the “evidence” for the possibility that DNA and DNA replication could emerge from simple molecules.

    First, this TEKS takes advantage of a common misunderstanding about evolution. Evolution occurs independently of how life originated. Even if intelligent aliens had dumped a soup of self-replicating molecules on Earth eons ago, all we know about evolution would still apply to life since that day. The answer to this question has no bearing on the vast majority of evolution theory. This is probably the most important thing for textbooks to clarify.

    Second, I think Dr. Wise overly complicates the rebuttal to Dembski. Sahotra Sarkar’s Doubting Darwin? has some great explanations of the problems with Dembski’s reasoning. Here I paraphrase a few:

    (1) Dembski’s “Design Inference” flow chart requires knowing the probability that an event will occur in advance of knowing whether the event occurred due to “regularity, chance, or design.” We have no such information.

    (2) Dembski’s flow chart requires that regularity, chance, and design be completely independent events — that there’s no feedback loop among them. This assumption by itself eliminates the possibility that any event could be a result of evolution. Evolution is based on a feedback loop between random chance and natural selection and not on either alone.

    (3) Dembski’s assumptions about what occurs by “regularity” and what occurs by chance are already known to be wrong. For example, quantum mechanics describes highly infrequent, low probability events, such as radioactive decay, that are both explained scientifically and not due to chance alone.

    (4) Dembski has never defined Complex Specified Information with enough specificity to even have the idea evaluated. Absent an intelligible definition, there is no theory, and there is nothing to be confirmed or refuted.

    (5) Dembski also posits a “Law of Conservation of Information.” He starts by inventing a definition for information different from all existing definitions. Dembski’s law says that the information content of two events occuring in combination equals at most the information content of any one of the events plus 500. That is, I(combined event) <= I(individual event) + 500. Dembski does not explain the constant 500. Dr. Sarkar looks at the case where two binary computer strings each N digits long are concatenated into a string of length 2N. Dembski's definition of information sets the information content of each original string to N and that of the combined string to 2N. Dembski's law therefore requires that 2N <= N + 500, and it's easy to see that string concatenation violates Dembski's law when each original string has 501 or more digits. (Okay, this refutation was a bit longer.)

    The purpose of this TEKS appears to be two-fold: to translate the lack of understanding about the origin of life into doubt about evolution, and to suggest that information considerations contradict all possible scientific explanations. Explaining the independence of evolution from the origin of life addresses the first issue. Dembski is the primary source of information-theoretic arguments against evolution and for the origin of life by supernatural means, so dispatching Dembski's arguments would both address this TEKS and give students a quick introduction to probability and information theory.

    In particular, it should be easy to translate Dr. Sarkar's argument in (5) into molecular terms, making it doubly relevant to this TEKS, given that we have approaches to measuring the information content of protein strands such as RNA and DNA.

  2. Joe Lapp Says:

    For clarity, my summation of Dembski’s law should read:

    I(combined event) <= I(any individual event) + 500

  3. Piedmont Says:

    Creationists pose these questions about evolution in such a manner that it is obvious they thnk there is no real answer to their questions, when in fact there are very good answers to all of their objections.

    This underscores how little creationists know about actual biology.

    They have included their ideas in the science standards and it will only serve to allow detailed explantions supporting evolution to be discussed in class.

    The science books should take this opportunity to debunk as much of creationism as possible by including very clear explanations and examples in the books. Make it so clear that even McLeroy and Lowe will understand.

    But that would require writing at a 3rd grade level.

  4. Doc Bill Says:

    McLeroy and Lowe don’t have to understand, nor do they want to understand, nor do they care.

    They are only interested in overturning what they see as a “materialistic,” that is, natural, world view and replace it with something that is compatible with their Christian philosophy. And, I use the term “philosophy” lightly because what the Lowe’s of the world actually propose is quite childish and unsophisticated.

    Simply put, the goal of these ideologues is to get Texas students to doubt that the origin and diversity of life could be explained by chemistry and physics, and to indoctrinate the students that the USA is a Christian nation. Like a dog chasing a car, though, I have no idea what they would do if they actually succeeded!

  5. Gordon Fowkes Says:

    Sticking to the random argument about natural selection leaves out that some selection is done intelligently or for whatever passes for smarts in the animal world.

    Intelligence selection occurs in those species in which a mating process is formalized such as shown on NatGeo (Wild). Sometimes the selection is the result of selection by combat between competing males, to which the winner gets humping rights.

    There is an identifiable teaching process in some species such as shown tonight with Orcas, seals, and sea lions.

    While one might say that the more intelligent selection has a higher probabillity of that particular genetic variation to survive. The question becomes is how does a species transmit a learned response multi-generationally speaking.

    Consequently both the intelligent design and the random mutation theory are flawed. It is the scientific process that is more important than any theory that I or any one else comes up with. I have seen the wave and particle theory of light drop out of sight.

  6. Piedmont Says:

    Gordon,

    You ramble like Kadaffy. You are really not fully rational and you don’t make sense.

  7. ogremkv Says:

    I’m working on a series of blog posts reviewing the current state of origins of life research. I’ve got three and the topic for the fourth. The three articles I have currently reflect IDs misconception on the odds of (various things), and two different paths that RNA can form from base resources. [click on the Origins of Life category to see all of them.]

    I also have some resources on the refutation of Intelligent Design (of course, who doesn’t?). [click on Intelligent Design or Creationism to see all of them.]

    Thanks
    Kevin

    Cassandra’s Tears

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