Genome complexity: epigenetics must be recognized (Introduction)

by David Turell , Saturday, April 11, 2020, 22:38 (1469 days ago) @ David Turell

A professor who studies epigenetics demands it be more fully integrated with Darwin theory, since he gets resistance from strict Darwinist scientists:

https://aeon.co/essays/on-epigenetics-we-need-both-darwin-s-and-lamarck-s-theories?utm_...

"One problem with Darwin’s theory is that, while species do evolve more adaptive traits (called phenotypes by biologists), the rate of random DNA sequence mutation turns out to be too slow to explain many of the changes observed. Scientists, well-aware of the issue, have proposed a variety of genetic mechanisms to compensate: genetic drift, in which small groups of individuals undergo dramatic genetic change; or epistasis, in which one set of genes suppress another, to name just two.

"Yet even with such mechanisms in play, genetic mutation rates for complex organisms such as humans are dramatically lower than the frequency of change for a host of traits, from adjustments in metabolism to resistance to disease. The rapid emergence of trait variety is difficult to explain just through classic genetics and neo-Darwinian theory.

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"In evolution and biomedicine, the rates of phenotypic trait divergence is far more rapid than the rate of genetic variation and mutation – but why?

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"At the start, Lamarck might have been pilloried as a religious heretic, but in modern times, it is the orthodoxy of science – and especially Darwin’s untouchable theory of evolution – that has caused his name to be treated as a joke. Yet by the end of his career, Darwin himself had come around; even without the benefit of molecular biology, he could see that random changes were not fast enough to support his theory in full.

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"Epigenetics involves a number of molecular processes that can dramatically influence the activity of the genome without altering the sequence of DNA in the genes themselves.
One of the most common such processes is ‘DNA methylation’, in which molecular components called methyl groups (made of methane) attach to DNA, turning genes on or off, and regulating the level of gene expression.

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"Another major epigenetic process discovered in recent years is ‘histone modification’. Histones are proteins that attach to and alter the structure of DNA, which in turn wraps around the histones like beads on a string.

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"More recently, researchers have documented ‘RNA methylation’ in which methyl groups attach to the genetic helper molecules, in the process altering gene expression and subsequent protein production for generations down the line. Likewise, the action of so-called ‘non-coding RNA’, small RNA molecules that bind to DNA, RNA and proteins, also alter the expression of genes, independent of DNA sequence.

"All of these epigenetic mechanisms are critical and have unique roles in the molecular regulation of how DNA functions. The regulation of biology, it follows, will never involve a ‘genetic-only process’, nor an ‘epigenetic-only process’. Instead, the processes of epigenetics and genetics are completely integrated. One does not work without the other.

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"Epigenetic transgenerational inheritance, by contrast, occurs when the germline (sperm or egg) transmits epigenetic information between generations, even in the absence of continued direct environmental exposures.

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"Environmentally induced epigenetic transgenerational inheritance has now been observed in plants, insects, fish, birds, rodents, pigs and humans. It is, therefore, a highly conserved phenomenon.

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"Neo-Darwinian and neo-Lamarckian mechanisms both drive evolution, and they appear to be intertwined.

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"Despite the pushback, I’m convinced that we have reached the point where a paradigm shift is due. Accepting that epigenetics plays a role in evolution does not topple the science of genetics; embracing neo-Lamarckian ideas does nothing to challenge classic neo-Darwinian theory. The accepted sciences are essential and accurate, but part of a bigger, more nuanced story that expands our understanding and integrates all our observations into a cohesive whole. The unified theory explains how the environment can both act to directly influence phenotypic variation and directly facilitate natural selection."

Comment: Readers of this website are not surprised by the importance of epigenetics. It's been covered well. The rigidity of the Darwinist group is well known. It is what I complain about when discussing Darwin theory. It is not Darwin's fault