“… nucleosomes as spools around which DNA is wrapped”, “a nucleosome spool with DNA wrapped around it” – when the guy can’t even get the correct definition of something he makes central in the article, what are the chances that there will be anything interesting there? Sheesh.

This is rather disgusting. First, DK does not make his point clear. Second, he proceeds from this unclarity to a condescending dismissal. And third, he is wrong if he is saying there is some sort of inconsistency in the phrases quoted. Karolin Luger, who first published the nucleosome structure, happened to remark in one of her later papers about the common misuse of the term “nucleosome”, mentioning that “the nucleosome actually *includes* the DNA”. Both of my remarks can and should be read as reflecting that understanding. I refer to nucleosomes as “spools around which the DNA is wrapped”, and I refer to the nucleosome spool “with DNA wrapped around it”. Finally, even if my language embodied the confusion rampant in the technical literature, it would hardly be a matter worth mentioning, for the same reason Luger doesn’t harp on the point: people don’t have much difficulty understanding what is being said. Why trivialize the discussion?

Quantitative genetic methods that estimate a substantial contribution of genetic variation to phenotypic variation do not now and has never told us anything about actual or counterfactual causal mechanisms involved. They have also never told us much about development other than what we already knew must be true — there will be genes involved in some way.

Nothing we’ve learned in the last 30 years about molecular biology makes any difference at a general level to those conclusions. What it mostly does is make clearer that the causal mechanisms behind phenotypic variation in complex traits are probably themselves really really complex.

As soon as you realize that complex traits have non-Mendelian inheritance patterns — something that’s been abundantly clear for many many decades — everything else follows and epigenetics only adds new dimensions to the causal mechanisms that might be involved.

Whether a trait is amenable to manipulation (and at what stages of development) is an interesting and very challenging question, but there’s no revolution in our understanding of biology involved in asking it. The only way to see a revolution is to ignore all of the incremental changes in understanding that have happened between decades.

that’s why i say link to the definitions of molecular biological stuff. let someone else take the fall if there’s an error.

When someone attempts that, it’s not a bad idea for that someone to familiarize himself with basic concepts and terms to start with.

“… nucleosomes as spools around which DNA is wrapped”, “a nucleosome spool with DNA wrapped around it” – when the guy can’t even get the correct definition of something he makes central in the article, what are the chances that there will be anything interesting there? Sheesh.