Regarding probability and enough time for common decent, I have read some articles.
"There's plenty of time for evolution," by Herbert S. Wilf and Warren J. Ewens, a biologist and a mathematician at the University of Pennsylvania was written as a rebuttal to those that say there was not enough time. "Our purpose here is to analyze this process, and our conclusion is that when one takes account of the role of natural selection in a reasonable way, there has been ample time for the evolution that we observe to have taken place." http://www.pnas.org/content/early/2010/1...7.abstract
However, it seems that the Wilf and Ewens model is too simplistic. http://www.evolutionnews.org/2012/12/pee...67421.html is an article about the paper addressing the above study. The article quotes the source paper in several places (citation below)
"Wilf and Ewens argue in a recent paper that there is plenty of time for evolution to occur. They base this claim on a mathematical model in which beneficial mutations accumulate simultaneously and independently, thus allowing changes that require a large number of mutations to evolve over comparatively short time periods. Because changes evolve independently and in parallel rather than sequentially, their model scales logarithmically rather than exponentially. This approach does not accurately reflect biological evolution, however, for two main reasons. First, within their model are implicit information sources, including the equivalent of a highly informed oracle that prophesies when a mutation is "correct," thus accelerating the search by the evolutionary process. Natural selection, in contrast, does not have access to information about future benefits of a particular mutation, or where in the global fitness landscape a particular mutation is relative to a particular target. It can only assess mutations based on their current effect on fitness in the local fitness landscape. Thus the presence of this oracle makes their model radically different from a real biological search through fitness space. Wilf and Ewens also make unrealistic biological assumptions that, in effect, simplify the search. They assume no epistasis between beneficial mutations, no linkage between loci, and an unrealistic population size and base mutation rate, thus increasing the pool of beneficial mutations to be searched. They neglect the effects of genetic drift on the probability of fixation and the negative effects of simultaneously accumulating deleterious mutations. Finally, in their model they represent each genetic locus as a single letter. By doing so, they ignore the enormous sequence complexity of actual genetic loci (typically hundreds or thousands of nucleotides long), and vastly oversimplify the search for functional variants. In similar fashion, they assume that each evolutionary "advance" requires a change to just one locus, despite the clear evidence that most biological functions are the product of multiple gene products working together. Ignoring these biological realities infuses considerable active information into their model and eases the model's evolutionary process.
Further down...
"In addition to the overwhelming problems mentioned above, the search algorithm they have chosen is unrealistic. Wilf and Ewens assume that the fitness landscape is smooth, with each beneficial mutation trending upward additively. This is not the case in biology. ...Indeed, there is much evidence to suggest that real fitness landscapes have many local fitness optima surrounded by fitness deserts. If it takes more than several mutations to move from one peak to another, adaptation can become stalled on a local peak, with no way to move from one small fitness peak to a higher one. Because natural selection is blind and without foresight, it cannot tell which particular mutations are leading to an unrealized goal of maximal fitness (in this case a target phrase) some distance away in the adaptive landscape. It can only assess the relative local fitness of variants in the population."
Winston Ewert, William A. Dembski, Ann K. Gauger, Robert J. Marks II, "Time and Information in Evolution," BIO-Complexity, Volume 2012 (4).
@Esquilax - you are right, poking holes in a theory is not proof of the competing theory. I am merely addressing the universal opinion here that common decent is a fact.
"There's plenty of time for evolution," by Herbert S. Wilf and Warren J. Ewens, a biologist and a mathematician at the University of Pennsylvania was written as a rebuttal to those that say there was not enough time. "Our purpose here is to analyze this process, and our conclusion is that when one takes account of the role of natural selection in a reasonable way, there has been ample time for the evolution that we observe to have taken place." http://www.pnas.org/content/early/2010/1...7.abstract
However, it seems that the Wilf and Ewens model is too simplistic. http://www.evolutionnews.org/2012/12/pee...67421.html is an article about the paper addressing the above study. The article quotes the source paper in several places (citation below)
"Wilf and Ewens argue in a recent paper that there is plenty of time for evolution to occur. They base this claim on a mathematical model in which beneficial mutations accumulate simultaneously and independently, thus allowing changes that require a large number of mutations to evolve over comparatively short time periods. Because changes evolve independently and in parallel rather than sequentially, their model scales logarithmically rather than exponentially. This approach does not accurately reflect biological evolution, however, for two main reasons. First, within their model are implicit information sources, including the equivalent of a highly informed oracle that prophesies when a mutation is "correct," thus accelerating the search by the evolutionary process. Natural selection, in contrast, does not have access to information about future benefits of a particular mutation, or where in the global fitness landscape a particular mutation is relative to a particular target. It can only assess mutations based on their current effect on fitness in the local fitness landscape. Thus the presence of this oracle makes their model radically different from a real biological search through fitness space. Wilf and Ewens also make unrealistic biological assumptions that, in effect, simplify the search. They assume no epistasis between beneficial mutations, no linkage between loci, and an unrealistic population size and base mutation rate, thus increasing the pool of beneficial mutations to be searched. They neglect the effects of genetic drift on the probability of fixation and the negative effects of simultaneously accumulating deleterious mutations. Finally, in their model they represent each genetic locus as a single letter. By doing so, they ignore the enormous sequence complexity of actual genetic loci (typically hundreds or thousands of nucleotides long), and vastly oversimplify the search for functional variants. In similar fashion, they assume that each evolutionary "advance" requires a change to just one locus, despite the clear evidence that most biological functions are the product of multiple gene products working together. Ignoring these biological realities infuses considerable active information into their model and eases the model's evolutionary process.
Further down...
"In addition to the overwhelming problems mentioned above, the search algorithm they have chosen is unrealistic. Wilf and Ewens assume that the fitness landscape is smooth, with each beneficial mutation trending upward additively. This is not the case in biology. ...Indeed, there is much evidence to suggest that real fitness landscapes have many local fitness optima surrounded by fitness deserts. If it takes more than several mutations to move from one peak to another, adaptation can become stalled on a local peak, with no way to move from one small fitness peak to a higher one. Because natural selection is blind and without foresight, it cannot tell which particular mutations are leading to an unrealized goal of maximal fitness (in this case a target phrase) some distance away in the adaptive landscape. It can only assess the relative local fitness of variants in the population."
Winston Ewert, William A. Dembski, Ann K. Gauger, Robert J. Marks II, "Time and Information in Evolution," BIO-Complexity, Volume 2012 (4).
@Esquilax - you are right, poking holes in a theory is not proof of the competing theory. I am merely addressing the universal opinion here that common decent is a fact.
