Cornell Conference Natural selection

Open Mike: Cornell OBI Conference Chapter 13—“Selection Threshold Severely Constrains Capture of Beneficial Mutations”—Abstract

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Biological Information

To facilitate discussion, we are publishing the abstracts and conclusions/summaries/Introduction excerpts of the 24 papers from the Cornell Conference on the Origin of Biological Information here at Uncommon Descent, with cumulative links to previous papers at the bottom of each page. You can get from anywhere to anywhere in the system.

Note: A blow-by-blow account of the difficulties that the authors experienced from Darwin lobby attempts to censor the book by denying it publication with Springer are detailed here. Fortunately, the uproar resulted in an opportunity for readers like yourself to read the book online. That said, the hard cover version is now shipping.

The Abstract for “Selection Threshold Severely Constrains Capture of Beneficial Mutations” by John C. Sanford, John R. Baumgardner, Wesley H. Brewer:

Background.In a companion paper, careful numerical simulation was used to demonstrate that there is a quantifiable selection threshold, below which low-impact deleterious mutations escape purifying selection and, therefore, accumulate without limit. In that study we developed the statistic, STd, which is the mid-point of the transition zone between selectable and un-selectable deleterious mutations. We showed that under most natural circumstances, STd values are surprisingly high, such that the large majority of all deleterious mutations are un-selectable. Does a similar selection threshold exist for beneficial mutations?

Methods. As in our companion paper we here employ what we describe as genetic accounting to quantify the selection threshold (STb) for beneficial mutations, and we study how various biological factors combine to determine its value.

Results. In all experiments that employ biologically reasonable parameters, we observe high STb values and a general failure of selection to preferentially amplify the large majority of beneficial mutations. High-impact beneficial mutations strongly interfere with selection for or against all low-impact mutations.

Conclusions. A selection threshold exists for beneficial mutations similar in magnitude to the selection threshold for deleterious ones, but the dynamics of that threshold are different. Our results suggest that for higher eukaryotes, minimal values for STb are in the range of 10-4 to 10-3. It appears very likely that most functional nucleotides in a large genome have fractional contributions to fitness much smaller than this. This means that, given our current understanding of how natural selection operates, we cannot explain the origin of the typical functional nucleotide. More.

See also: Origin of Biological Information conference: Its goals

Open Mike: Origin of Biological Information conference: Origin of life studies flatlined

Open Mike: Cornell OBI Conference— Can you answer these conundrums about information?

Open Mike: Cornell OBI Conference—Is a new definition of information needed for biology? (Chapter 2)

Open Mike: Cornell OBI Conference—New definition of information proposed: Universal Information (Chapter 2)

Open Mike: Cornell OBI Conference—Chapter Three, Dembski, Ewert, and Marks on the true cost of a successful search

Open Mike: Cornell OBI Conference—Chapter Three on the true cost of a successful search—Conservation of information

Open Mike: Cornell OBI Conference—Chapter Four: Pragmatic Information

Open Mike: Cornell OBI Conference—Chapter Four, Pragmatic information: Conclusion

Open Mike: Cornell OBI Conference Chapter Five Abstract

Open Mike: Cornell OBI Conference Chapter Five – Basener on limits of chaos – Conclusion

Open Mike: Cornell OBI Conference Chapter Six – Ewert et all on the Tierra evolution program – Abstract

Open Mike: Cornell OBI Conference Chapter Six – Ewert et all on the Tierra evolution program – Conclusion

Open Mike: Cornell OBI Conference Chapter 7—Probability of Beneficial Mutation— Abstract

Open Mike: Cornell OBI Conference Chapter 7—Probability of Beneficial Mutation— Conclusion

Open Mike: Cornell OBI Conference Chapter 8—Entropy, Evolution and Open Systems—Abstract

Open Mike: Cornell OBI Conference Chapter 8—Entropy, Evolution and Open Systems—Conclusion

Open Mike: Cornell OBI Conference Chapter 9—Information and Thermodynamics in Living Systems—Abstract

Open Mike: Cornell OBI Conference Chapter 9—Information and Thermodynamics in Living Systems—Conclusion

Open Mike: Cornell OBI Conference Chapter 10—Biological Information and Genetic Theory: Introductory Comments—Abstract

Open Mike: Cornell OBI Conference Chapter 10—Biological Information and Genetic Theory: Introductory Comments— Excerpt

Open Mike: Cornell OBI Conference Chapter 11—Not Junk After All—Abstract

Open Mike: Cornell OBI Conference Chapter 11—Not Junk After All—Conclusion

Open Mike: Cornell OBI Conference Chapter 12—“Can Purifying Natural Selection Preserve Biological Information?”—Abstract

Open Mike: Cornell OBI Conference Chapter 12——“Can Purifying Natural Selection Preserve Biological Information?”—Excerpt

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