This 2014 ivy league human study found that what appeared to be genetic links may have been epigenetic responses to our environment.
Curiously, none of the news articles covering this study highlighted the lack of the most influential environments on epigenetic DNA changes:
- The mother’s prenatal environment provided for the fetus, and
- The family environment during infancy and early childhood.
This omission may have been because the study intentionally didn’t support such an interpretation. Here’s a partial explanation from the study’s supplementary material of the “family fixed-effects model” the researchers developed:
“The family fixed-effects model blocks both genetic factors and parental characteristics/behaviors that are common to family members (e.g., siblings), including unmeasured factors; therefore, from the perspective of confounding, the fixed-effect specification is preferred.”
When the preferred model blocked the most important environments in which epigenetic DNA changes occur, what environments remained?
“These results suggest genetic influences on complex traits like obesity can vary over time, presumably because of global environmental changes that modify allelic penetrance.”
Although a finding attributing “global environmental changes” made more funding available to the researchers, it was rightly an outlier from the majority of epigenetic studies.
Why was the reviewer okay with the study’s model omitting the most important factors in human development? In my view, its model defined away both the:
- Out-of-favor genetic factors, and the
- Predominant but nonpolitically-correct epigenetic factors
in order to manufacture a politically-correct epigenetics meme.
How else to interpret this statement, if not intended to generate a meme?
“Our results underscore the importance of interpreting any genetic studies with a grain of salt and leave open the possibility that new genetic risk factors may be seen in the future due to different genetically driven responses to our ever-changing environment.”
http://www.pnas.org/content/112/2/354.full “Cohort of birth modifies the association between FTO genotype and BMI”