Evolution is Stopped Cold by the Side Effects of Mutations!

Evolution needs mutations working together for one species to result in the next "just-so" species on the fantastic tree of life. But Pleiotropy bars the way!

Article Review: "The Pleiotropy Problem for Evolution", by Jerry Bergman

Marko's Executive Summary:

"Pleiotropy" is an awful sounding word. But the most awful thing about Pleiotropy is that it stops Evolution cold. If a mutation results in the loss or change in just one function of a living creature, it will probably also result in the loss of many other functions, too. And this will certainly disrupt all those mutations working together to produce a more advanced species.

This is why I'm calling this post "Evolution is Stopped Cold by the Side Effects of Accumulated Mutations!". That's the first item.

A second item is that Pleiotropy makes it extremely difficult for Evolution to explain how creatures like dogs and their wolf cousins supposedly mutated from their pre-wolf forebears. You see, dogs and wolves are a "high plasticity" life-form, as we all know from all the different breeds of dogs. Plastic species have a greater proportion of their traits coded by a single gene. So, how could all those very important single genes evolve perfectly from their ancestors, given the pitfalls of multiple side affects which would certainly bring the entire dog line down to its knees?

Pleiotropy runs counter to Evolution. As Jerry Bergman tells us in his paper titled "The Pleiotropy Problem for Evolution", not only does Pleiotropy "create a major genetic barrier to both micro- and macroevolution, but it also even sets limits on animal and plant breeding because of the biochemical interconnectivity existing in cells, tissues, organs, and organ systems." Evolution requires easy access to mutational avenues, but Pleiotropy is a great barrier.

In case you're asking the question "Where did dogs and wolves come from?", Bergman's answer is: "The evidence of pleiotropy favors special creation." What he means by "special" is that there was an intelligent designer at work to create dogs and wolves, not to mention all the other creatures as well.  Here is yet another place where the Creator God shows up in Science!

(This review and article digest is by Marko Malyj, of the article published in Creation Research Society Quarterly Journal, Volume 46, Number 4, Spring, 2010, to appear at http://www.creationresearch.org/crsq/abstracts/Abstracts46-4.htm). {Original version of this blog post with all pictures is available at http://umarko.blogspot.com. My comments that are not in the original published version are offset in curly braces.}

Abstract

Pleiotropy is the effect resulting from an interconnected genetic system in which a single gene influences many different biological systems in positive or negative ways.... Pleiotropy creates a major problem for evolutionary theory because the accumulation of mutations, even beneficial mutations, often has unintended negative effects.

Introduction

Pleiotropy - from pleio, meaning "many", and tropo, meaning "changes" - is defined as the situation in which a single genetic variant is responsible for a number of distinct and often unrelated phenotypic effects (King and Stansfield, 1997, p. 264). Genes never operate alone.... Even if a mutation is positive for one trait, negative effects frequently result as well, creating what is termed a "fitness cost". In humans the result is obvious when a single mutation causes a disease that produces many unrelated symptoms (Dudley et al., 2005).

The best-known example is ... sickle-cell anemia, a disease that results from a single mutation in the hemoglobin gene. Beside anemia, other physical complications include leg ulcers, bone problems, blood clots, anoxia caused by the abnormal blood cells that lack the ability to flow properly, spleen damage, strokes, and hemolysis.

Pleiotropy, Mutations, and Evolution


The disadvantage for evolution by mutations is: If a particular phenotype is the result of a mutation that produces the loss or alteration of a single function, it may also cause the loss of other functions that are required by disrupting part of a branching pathway.

This impediment to evolutionary progress is called "the cost of complexity" (Orr, 2000, p. 13).

How Common is Pleiotropy?

Much research indicates that most, and possibly all, genes have a pleiotropic effect.

Hodgkin (1998, p. 501) argued that pleiotropy "may well be the rule rather that the exception in higher organisms".... Jaroslav Flegr has proposed that pleiotropy limits the plasticity of a species (Hall, 2009). High plasticity life-forms, such as dogs, are able to produce many morphological variations, and plastic species have a greater proportion of their traits coded by a single gene.

Summary

Pleiotropy not only creates a major genetic barrier to both micro- and macroevolution, but it also even sets limits on animal and plant breeding because of the biochemical interconnectivity existing in cells, tissues, organs, and organ systems.... As Hodgkin (1998, p. 501) admitted, "In complex eukaryotes, pleiotropy may lead to major constraints on possible mutational avenues" that might allow evolution to occur.

The evidence of pleiotropy favors special creation {!!} (Tinkle, 1975)

References (selected)

Dudley, A.M., D.M. Janse, A. Tanay, R. Shamir, and G.M. Church. 2005. A global view of pleiotropy and phenotypically derived gene function in yeast. Molecular Systems Biology doi:10.1038/msb4100004-E1.

Hall, B.K. 2009. Review of Frozen Evolution: Or That's Not the Way It is, Mr. Darwin, edited by Jaroslav Flegr. Evolution & Development 11(1):126-129.

Hodgkin, J. 1998. Seven types of pleiotropy. International Journal of Developmental Biology. 42:501-505.

King, R., and W. Stansfield. 1997. A Dictionary of Genetics. Oxford University Press, New York, NY.

Orr, H.A. 2000. Adaptation and the cost of complexity. International Journal of Organic Evolution. 54:31-20.

Tinkle, William J. 1975. Further research on reduced viability of mutant plants. Creation Research Society Quarterly 12:52.