Thursday, February 13, 2014

More evolving fish

A pair of Atlantic killifish (Fundulus heteroclitus).
Credit: Evan D'Alessandro, Rosentstiel School of Marine and
Atmospheric Science.  Image source.
Due to the ambiguity of the word "evolution," claims that evolution is scientifically proven are unfortunately misunderstood by many proponents of the evolutionary model of the history of life.  To support the idea that all life shares a single common ancestor, many people and even textbooks cite studies showing change in modern animals to adapt to changing conditions.  However, such observed evolutionary events are unrelated to the type of "evolution" needed to produce the modern diversity of organisms from a single primordial cell, or what I call the theory of universal common ancestry.

One such study that purports to show "evolution in action" comes out of the Woods Hole Oceanographic Institution.  The study, published online last month in BMC Evolutionary Biology, investigated the Atlantic killifish (Fundulus heteroclitus) living in the polluted waters of New Bedford Harbor in Maryland.  The pollutants in the water, particularly polychlorinated biphenyls (PCBs), are toxic to the fish, yet a population of killifish seems to thrive there.  The scientists found that in most killifish, enzymes are produced to break down the PCBs, but the enzymes are not very effective at doing so.  The cells simply continue producing these enzymes, disrupting normal cell function and eventually killing the fish in a process that could roughly be likened to a severe allergic reaction in humans.  It appears, then, that it is not the pollutants themselves that are harming the fish, but the fish's own immune systems.  However, the killifish that thrive in New Bedford Harbor have a mutation in the gene that controls the production of the enzyme, rendering it useless.  Therefore, the bodies of these fish do not kill themselves in attempting to fight the pollutants, and they have an easier time surviving the polluted waters than the killifish without the mutation.

This is indeed an example of natural selection causing changes in an organism to adapt to new circumstances, but is it evidence of evolution on a grand scale?  First, the study notes that the mutation is not limited to the killifish of New Bedford Harbor; it is just far more common there.  Second, the adaptation consists of a loss of function and genetic information, as does every modern example of "evolution in action."  Technically speaking, this is evolution, but it is not the type of change necessary for the theory of universal common ancestry.  For a single cell to evolve into a fish, and a fish into an amphibian, and an amphibian into a mammal, drastic additions are needed to the genome, including new functions and information not previously present in the population.  However, this type of change has never been observed.  Continued changes like those seen in the killifish could never produce a new kind of animal, no matter how much time is allowed, because the changes are in the wrong direction.  The only scientifically validated means of addition of information is the input of an intelligent source.  Even if science can't prove the existence or action of God, it is only logical to conclude that from our current understanding of biology and information, the great variety of information contained in the DNA of living organisms must be traced back to the Creator.

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