2017/01/31

Population genetics can't solve the 'Missing Heritability' problem

Do we really want to squander our time and resources chasing ghosts?


Excerpt: "By Evan Charney, Duke Institute for Brain Science, Duke University:
One of the hopes and promises of the Human Genome Sequencing Project was that it would revolutionize the understanding, diagnosis, and treatment of most human disorders. It would do this by uncovering the supposed “genetic bases” of human behavior. With a few exceptions, however, the search for common gene variants -“polymorphisms” – associated with common diseases has borne little fruit. And when such associations have been found the polymorphisms seem to have little predictive value and do little to advance our understanding of the causes of disease. 


And to date, not a single polymorphism has been reliably associated with any psychiatric disorders nor any aspect of human behavior within the “normal” range (e.g., differences in “intelligence”).



To some researchers this state of affairs has given rise to a conundrum known as the “problem of missing heritability.” If traits such as intelligence are reported to be 50% heritable, goes the theory, why have no genes associated with intelligence been identified?

...GCTA studies, however, just like their twin study predecessors, suffer from serious methodological problems that call into doubt the legitimacy of their findings. They, too, are likely to generate spurious associations and faulty estimates of genetic contributions to variation in traits.

One well-known example of a false association between a polymorphism and a trait was the link between the dopamine receptor gene DRD2 and alcoholism. Initial studies suggested a strong association, but subsequent investigations found none when more effective controls for population stratification were imposed.

Advocates of GCTA, however, tell us that in order to find the multitude of polymorphisms of tiny effect underlying heritability estimates we must undertake ever larger studies involving hundreds of thousands of persons. These polymorphisms of tiny effect, however, are so many ghosts and the search for them is the last gasp of a failed paradigm. Do we really want to squander our time and resources chasing ghosts?"

My comment: Population genetics is the most significant field of pseudosience that maintains the heretical darwinian theory of evolution. There are over 900,000 SNPs identified in the human genome but not a single polymorphism has reliably associated with any psychiatric disorder or trait linked to human intelligence. Only few SNPs are confirmed to be associated with adaptation and those changes in genome are contributed by mechanisms involved in the immune system (for example lactose tolerance and high altitude adaptation). The conclusion is obvious: GENES ARE NOT DRIVERS. The missing heritability problem is solved by deep understanding of how epigenome is regulated. Within this concept, there are several factors influencing the orchestra: non coding RNA molecules, RNA methylation, exosomes, extracellular vesicles, DNA methylation, histone methylation/acetylation, prions, flanking binding sites and several other mechanisms that affect transgenerational epigenetic inheritance. Changes organisms experience are not based on random errors but Intelligently designed and created mechanisms. These mechanisms are not designed to cause large scale evolution, but only rapid and effective adaptation that prepares the offspring for changing environment. Don't get lost.