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Saturday, August 30, 2014

Darwin's Finches and Epigenetics

Galapagos finches ("Darwin's finches") have been touted as good evidence for evolution. Beak sizes changed, therefore, evolution. Unfortunately for Darwin's Cheerleaders, they are not only extrapolating small changes into justifying goo-to-you evolution, but variations and speciation are not evolution (except in the loosest definition of the word). In fact, some evolutionists think that these small changes are a slap in the face of creationists, but they are uninformed about creationists: we know about speciation, and it fits with the biblical models.


Medium Ground Finch, John Gould / PD
Traditional Darwinian evolution held that small changes led to big changes and eventually, something would turn into something else. That was largely abandoned with more understanding of genetics and mutations. However, variations are limited by genetics, so you still will not get something changing into something else; there is no vertical evolution. Now scientists are learning that a major factor in change is epigenetics.
Authentic speciation is a process whereby organisms diversify within the boundaries of their gene pools, and this can result in variants with specific ecological adaptability. While it was once thought that this process was strictly facilitated by DNA sequence variability, Darwin's classic example of speciation in finches now includes a surprisingly strong epigenetic component as well.

Epigenetic changes involve the addition of chemical tags in an organism's genome without actually changing the genetic code. Both the DNA nucleotides and the proteins that DNA is wrapped around (called histones) can be chemically tagged by different types of controlling molecules that determine how genes are turned on and off. Thus, the epigenetic regulation of the genome can produce differences in traits without actually being related to changes in the DNA sequence itself. What's even more amazing is that these changes can be inherited over multiple generations. Thus, epigenetic changes unexpectedly facilitate variability and speciation within created kinds.
To finish reading, dip your beak into "Darwin's Finches: Answers From Epigenetics".

2 comments:

Piltdown Superman said...

Impugning character and putting words in people's mouths (straw man) also gets your indignant comments deleted.

Piltdown Superman said...

Since I have neither time nor interest in playing games with children here, I'm just shutting off the comments.