Primer: ‘Self-Replicating Life’

by TFN

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.

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