Comments on: Beware of scientific revolutions!

By: biologist

biologist — Mon, 29 Aug 2011 01:11:15 +0000

in the cases of epistasis, intuition is incorrect about it causing substantial non-additive variance

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2265475/
“Data and Theory Point to Mainly Additive Genetic Variance for Complex Traits”

Abstract: The relative proportion of additive and non-additive variation for complex traits is important in evolutionary biology, medicine, and agriculture. We address a long-standing controversy and paradox about the contribution of non-additive genetic variation, namely that knowledge about biological pathways and gene networks imply that epistasis is important. Yet empirical data across a range of traits and species imply that most genetic variance is additive. We evaluate the evidence from empirical studies of genetic variance components and find that additive variance typically accounts for over half, and often close to 100%, of the total genetic variance. We present new theoretical results, based upon the distribution of allele frequencies under neutral and other population genetic models, that show why this is the case even if there are non-additive effects at the level of gene action. We conclude that interactions at the level of genes are not likely to generate much interaction at the level of variance.

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if you take each of the suggested mechanisms one at a time you find basically the same conclusion. while these mechanisms are interesting biologically they do not contribute substantially to non-additive variance for most complex traits — at least according to the available evidence and theory.

By: DK

DK — Mon, 29 Aug 2011 01:00:56 +0000

This ignores everything everything we now know about the way genes work. Genes are not self-activating: they do not turn themselves on and produce traits. Genes do not, in fact, produce anything. Genes are turned on and off by the epigenome

I stopped reading there. A person writing stuff like this cannot possibly say anything worthwhile reading on any subject even most tangentially related to genes.

By: Bob

Bob — Sun, 28 Aug 2011 18:13:16 +0000

Well, it seems a shame to me: I suspect she’s (he’s?) non-stupid. I’m guessing she is in a group (Sociology department?) where they say this kind of thing to each other. It lets them enjoy a belief that they’re up on the latest science, while at the same time steering clear of anything conceivably racist. What a mess.
Cheers,
–Bob

By: observer

observer — Sun, 28 Aug 2011 17:44:22 +0000

The appeal to epigenetics as the “way out” from the often decisive impact of genetics is just one more rearguard action employing obfuscation as its primary weapon. As with the others, it takes a phenomenon of limited application and significance, and attempts to blow it up into an overarching account that explains everything inconvenient away.

But it is based, of course, in ignorance — the ignorance of the obfuscator, and the hoped for ignorance in the audience.

By: ackbark

ackbark — Sun, 28 Aug 2011 17:01:04 +0000

Her tone reminds me of some kind of house style of something I cannot put my finger on.

What is it?

By: Darkseid

Darkseid — Sun, 28 Aug 2011 16:04:03 +0000

i’m still, and always will be, a beginner but isn’t the epigenome inherited as well? otherwise, how would any gene ever get any directives at any time? it seems she’s mistaken and also very condescending and pretentious. that’s a good commenting policy, though. the more deleted comments there are tighter the discussion gets. a person like me may not realize she’s completely wrong and, thus, am getting bad info (indirectly) from this site and it also wastes everyone’s time and depletes your daily decision making energy for no reason.

By: John Emerson

John Emerson — Sun, 28 Aug 2011 11:25:46 +0000

Thomas Kuhn hated the way his ideas were received even in the scientific and scholarly community, to say nothing of the general culture. He regretted that he had ever used the phrase “paradigm shift” or even the word “paradigm”.

In 1999 one of the stupidest people I’ve ever known, a woman running the knicknack section of a bookstore, came in from a management in-service completely pumped about The Paradigm Shift To Excellence. That was the bottom. There’s nowhere to fall from there.

By: Justin Giancola

Justin Giancola — Sun, 28 Aug 2011 11:05:00 +0000

Symbiogenesis: wow, that’s pretty neat stuff; the full version of that idea was new to me. If it indeed applies to mitochondria, then why just?