I vividly remember the July morning in 2000 when the New York Times printed a front page article reporting the White House announcement that we finally had unraveled the structure of our DNA: the collection of genes that make living things who and what they are. Among the other amazing revelations, it was apparent that the genomes of all living things are very similar to one another, reinforcing the conviction that we have a complex and genuine kinship with all the creatures of the earth. The second surprise was that the number of genes in the human genome is surprisingly modest: around 24,000. How was this relatively tiny collection of genes responsible for the enormous variability of humans? The third irresistible insight was that if we could describe our genome, we could change it and in fact make entirely new, synthetic genomes in the laboratory. We were off and running on what promises to be the greatest age of scientific progress in the history of the world.
The highlight of my week is always reviewing summaries of what’s new in the biomedical universe as my two favorite journals, Nature and Science, report them. In only the past month, the tremendous usefulness of studying DNA in novel ways continues to be evident. For example:
- Monitoring hard to find rare species of animals through collecting the DNA they drop into their environment. Wildlife managers use DNA droppings to trace endangered or elusive life forms all the time. Michael Schwartz, who heads the US Forest Service’s National Genomics Center for Wildlife and Fish Conservation in Montana, was able to monitor the endangered bull trout and trace the presence of the elusive Canada lynx and wolverine in Montana.
- Fascinating documentation of previously unrecognized features of ancient civilizations are being reported. For example, Science writer Lizzie Wade reported that immigrants from the Middle East shaped Rome and that there was little European DNA at the height of the imperial period! Archeologists studied remains of 127 people who died over 12,000 years of history in and around Rome; and documented an influx of early farmers from what is now Turkey that transformed the genetic pool about 9,000 years ago. Interestingly, though, the oldest DNA found did resemble that of other European hunter-gatherers.
- DNA research is now proving that early settlers moved around and did not, in fact, exist in isolated communities; Feinman and Neitazel in the November 9 issue of Science showed that such communities were not tightly constrained, but the need for food and improved climate motivated what the authors called the “mobility and migration…essential to the human historical experience.”
- Even in prehistoric times, social strata in some civilizations were carefully defined and guarded: Mittnik et al reported in Science that during the Bronze age, social status, inheritance rules and mobility were all important factors in defining what they called a “high status core family and unrelated low-status individuals”. Such systems were stable for over 700 years.
- My favorite is perhaps the work of MacArthur genius grant recipient Nancy Moran, who showed how living forms that have genomes so small they can’t survive on their own depend on what she calls “microbial cargo”
in their bodies which have supplemental DNA that together with the poverty-stricken host makes a functioning organism.
- Researchers continue to try to correlate genomes with behavior and personality—often a risky, uncertain business. For example, research in a British coal mining village found that some DNA of people in the district was “flecked with disadvantage” and was associated with spending fewer years in school and lower socio-economic status; David Adam, reporting in Nature, points out how difficult it is to associate genomic structure with function. But the impact of a constricting environment in which inhabitants spend generations in deep coal mines on gene expression is probably deeply relevant to the correlation of biology with ecology.
This is a new golden age in medicine. Through genomic science we are finding out how we came to be who we are. New, effective ways of looking at life is helping to illuminate the cause of disease, frailty and aging, pointing out powerful new treatments for all that ails us. It’s a uniquely exciting time.
Dr. Marianne Legato, Professor Emerita of Clinical Medicine at Columbia University is an internationally known academic physician, author, lecturer, and specialist in gender-specific medicine. She is founding member of the International Society for Gender Medicine and also the founder and director of The Partnership for Gender-Specific Medicine at Columbia University and its next iteration, The Foundation for Gender-Specific Medicine. These enterprises are the first collaborations between academic medicine and the private sector focused solely on gender-specific medicine: the science of how normal human biology differs between men and women and of how the diagnosis and treatment of disease differs as a function of gender and sex. Her ground breaking textbook on Gender-and Sex Specific Medicine has been published in 2017 in the 3rd edition.
She has published extensively on Gender and Sex Specific Medicine, both scientifically and for the lay public. She is also the founding editor of the journal Gender Medicine, and the Journal Gender and Genome, published for the scientific community. In 1992, Dr. Legato won the American Heart Association’s Blakeslee Award for the best book written for the lay public on cardiovascular disease. She is a practicing internist in New York City and has been listed each year in New York Magazine’s “Best Doctors” since the feature’s inception in 1993.