social life and the changing expressions of genes

social isolation

The Social Life of Genes by David Dobbs at Pacific Stan­dard

The recent explo­sion of inter­est in “epi­ge­net­ics” — a term lit­er­ally mean­ing “around the gene,” and refer­ring to any­thing that changes a gene’s effect with­out chang­ing the actual DNA sequence — has tended to focus on the long game of gene-​environment inter­ac­tions: how famine among expec­tant moth­ers in the Nether­lands dur­ing World War II, for instance, affected gene expres­sion and behav­ior in their chil­dren; or how mother rats, by lick­ing and groom­ing their pups more or less assid­u­ously, can alter the wrap­pings around their offspring’s DNA in ways that influ­ence how anx­ious the pups will be for the rest of their lives. The idea that expe­ri­ence can echo in our genes across gen­er­a­tions is cer­tainly a pow­er­ful one. But to focus only on these nar­row, long-​reaching effects is to miss much of the action where epi­ge­netic influ­ence and gene activ­ity is con­cerned. This fresh work by Robin­son, Fer­nald, Clay­ton, and oth­ers — encom­pass­ing stud­ies of mul­ti­ple organ­isms, from bees and birds to mon­keys and humans — sug­gests some­thing more excit­ing: that our social lives can change our gene expres­sion with a rapid­ity, breadth, and depth pre­vi­ously overlooked.

Why would we have evolved this way? The most prob­a­ble answer is that an organ­ism that responds quickly to fast-​changing social envi­ron­ments will more likely sur­vive them. That organ­ism won’t have to wait around, as it were, for bet­ter genes to evolve on the species level. Immu­nol­o­gists dis­cov­ered some­thing sim­i­lar 25 years ago: Adapt­ing to new pathogens the old-​fashioned way — wait­ing for nat­ural selec­tion to favor genes that cre­ate resis­tance to spe­cific pathogens — would hap­pen too slowly to counter the rapidly chang­ing pathogen envi­ron­ment. Instead, the immune sys­tem uses net­works of genes that can respond quickly and flex­i­bly to new threats.

We appear to respond in the same way to our social envi­ron­ment. Faced with an unpre­dictable, com­plex, ever-​changing pop­u­la­tion to whom we must respond suc­cess­fully, our genes behave accord­ingly — as if a fast, fluid response is a mat­ter of life or death.

psychiatry. behavior. genetics.

insane asylum
the crum­bling pil­lars of behav­ioral genet­ics by jay joseph

Schiz­o­phre­nia researcher Tim­o­thy Crow wrote in 2008 that mol­e­c­u­lar genetic researchers inves­ti­gat­ing psy­chotic dis­or­ders such as schiz­o­phre­nia had pre­vi­ously thought that “suc­cess was inevitable-​one would ‘drain the pond dry’ and there would be the genes!” But as Crow con­cluded, “The pond is empty.” Four years later the psy­chi­atric dis­or­der and psy­cho­log­i­cal trait “gene ponds” appear to have been com­pletely drained, and there are few if any genes to be found. Twenty years ago, how­ever, lead­ing behav­ioral geneti­cists had high expec­ta­tions that mol­e­c­u­lar genetic research would soon “rev­o­lu­tion­ize” the behav­ioral sciences.