A plea for population genetics

By Razib Khan | October 10, 2012 10:31 pm

The title here is somewhat misleading. This is not just a plea for population genetics, but for quantitative genetics as well. Genetics is a big field. But today it is defined by and large by DNA, the concrete entity in which the abstraction of the gene is embedded. Look at the header of this website, or the background to my Twitter account. Mind you, I’m pathetically informed about molecular genetics, and don’t have a strong interest in the topic! I did consider using the H.W.E. or the breeder’s equation for the header, but in the end I judged it too abstruse and unfamiliar to most readers. DNA dominates when it comes to the modern mental conception of genetics, and we have to live with it to some extent.
But there is also great value in the genetics which has intellectual roots in the pre-DNA Mendelians and biometricians. This genetics exhibits a symbiotic, but not necessary, association with genetics as a branch of biophysics. Yet I come here not to insult or impugn my friends who toil in the trenches of the molecular wars. Rather, I simply want to point out that our world needs balance, and the systematic aerial perspective of population, evolutionary, and quantitative genetics can provide a different kind of intellectual ballast. More importantly, for the mnemonically lazy in the audience pop, evo, and quant gives you information for free. By this, I mean that these are highly theoretical fields, and theory can predict and allow you to infer facts about the world. You don’t need immerse yourself in every scrap of data if you can derive the likely probable pattern from theory.

In some ways you might classify molecular geneticists as hedgehogs and pop and quant geneticists as foxes. Often this is meant to denigrate the group labeled as hedgehogs, with their narrow and single-minded focus on a specific topic or question. But the world needs both hedgehogs and foxes. I would hope that many biomedical geneticists were hedgehogs, with a single-minded devotion to their particular domain of inquiry. On the other hand the world would probably benefit from a sprinkling of foxes within biomedicine as well.

But in some ways pop and quant genetics is more useful in the day to day than molecular genetics. People I encounter regularly talk about heritable traits, and the nature of heritability, without any clear and concise way to frame and flesh out their thoughts. For example, will smart people have smart children? Tall people tall children? Ugly people ugly children? These are questions where the molecular geneticist doesn’t have any tools to tackle, but some quick & dirty quantitative genetic models can help in a pinch. And of course today with the rise of genomics, and the likely ubiquity of personal genomics, some formal frameworks in understanding the system of genetics can be quite handy and practical in the “news you can use” sense.

What next? First, I hope people keep an open mind about things. People seem to have a discomfort with the reality that there are statistical patterns in the world, including heritable ones. Part of this is mathphobia, but part of it is probably Gattacanism. Second, there are good books you can read. Third, feel free to continue reading my blog, but engage in the comments and ask for clarification (the answers are quite likely to come from readers which far greater fluency in these domains than myself). I hope to run into you at a party soon!

Image credit: Wikipedia.

Addendum: Does anyone know of a usable photo of Sewall Wright which isn’t copyrighted?

CATEGORIZED UNDER: Population Genetics
  • http://3lbmonkeybrain.blogspot.com/ Mike Keesey (@tmkeesey)

    What is “Gattacanism”? (Term doesn’t appear on the linked page, and I can’t be sure if you’re referring to the societal mindset within the film or the refutation of that mindset by the film.)

  • jurble

    Is a plea for population genetics a plea for population geneticists? I still need to apply to grad school, so why not population genetics, I suppose…

  • https://plus.google.com/109962494182694679780/posts Razib Khan

    #1, i just made up the world. basically any discussion of the impact of genetics on society has to take gattaca into account. it’s fiction become fact in the minds of most moderns.

    #2, population genetics is population geneticists 😉 though probably i’d recommend people go specifically into population genomics. the old wily theorists are probably not going to retire anytime soon, but there’s still more big data to come.

  • Charles Nydorf

    I like the idea of a genetics pope based in the Gattican!

  • Chad

    I think genomics is breaking down a lot of the barriers that once existed between the two fields.

    For the foreseeable future there will always be molecular geneticists (or biologist….I have always found these terms vague) as it represents a bridge between genetics and biochemistry.

    But beginning with arrays and now next gen sequencing, I increasingly see more traditionally molecular labs make the jump to genome wide technologies for gene expression of protein binding. Next gen sequencing has also “democratized” genomes, where now it is possible and increasingly common for a single lab to sequence de novo and entire genome or transcriptome of organisms or individuals they always wanted genome wide information on. There are increasingly attempts to also merge various types of genome-wide data. Whole Genome Sequencing + Bisulphate (methylation) + ChipSeq (protein-DNA) + transcriptome data. A lot of papers are utilizing at least 2 or 3 of this data tied along with phenotypic or biochemical data.

    I grant it, this is still very different than population genetics or quantitative genetics, but it requires a different mindset when one goes from handling one gene to quantitative information about tens of thousands. It is also a big step when these experiments begin trying to molecular data like gene expression to the underlying genotypes.

    I think there is still a long way to go, but I think the genomics technologies are enabling the development of a true hybrid field that sits at the crossroads of population and/or quantitative genetics and molecular genetics.

    #2 I have no idea of your specific interests, but I would highly recommend finding a lab that firmly has its foot in genomics. If you like plants I can point you in the right directions.

  • LindaCO

    Pop gen rules!! From a person working in mosquito pop gen at the moment.

  • jurble

    To #5(such a strange way of addressing people here!). I’m opposed to plants! I more or less find most things biological interesting.


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This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com


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