Genetic studies: Let’s cast a wider DNA net

livemint.com:

In a paper published this week in Nature, part of a series of insights about ancient peoples, researchers compared thousands of ancient and modern genomes to unearth new information about multiple sclerosis (MS). The findings help scientists make the case that northern Europeans’ elevated risk of MS is a 5,000-year-old relic of becoming sheep and cattle herders. Mutations that make some people more vulnerable to the neurological condition once had a useful function, protecting their ancestors from pathogens.

In other words, in battling some diseases, we’re up against thousands of years of evolution. No wonder finding good medicines is such a slog. The work is an amazing tech feat, laying out a blueprint for how to use large sets of ancient genomes to probe the origins and spread of disease.

And while that won’t directly lead to new medicines, insights from ancient ancestors can be of treatment help. What new revelations about human health and disease might lie not in our own individual genomes, but in comparing our DNA to our ancient ancestors’ or even to those of other species? By extracting genetic material from the bones and teeth of specimens borrowed from museums and pooling it with genomic data on other ancient Europeans, the research team were able to trace back the introduction of genetic risk factors for MS. They found a distinct signal about 5,000 years ago, when steppe herders migrated into Northern Europe.

The data suggests that the introduction of farm animals into daily life exposed people to new pathogens, which in turn led to the protective mutations that pepper the genomes of descendants from that population. But our lifestyle has radically changed in the past 200 years. Basic hygiene is vastly