Does Our DNA Pass Down Environmental Traits?

The discovery of epigenetics ~ hidden influences upon the genes ~ presents huge implications for what and how we inherit traits, including those passed down from ancestors.

At the heart of this new field is the idea that genes have a 'memory'. This means the lives of your grandparents ~ the air they breathed, the food they ate, even the things they saw ~ can directly affect you despite your never experiencing these things yourself. And that what you do in your lifetime could affect your grandchildren.

Scientists believe DNA carries all our heritable information and that nothing people do in their lifetimes will be biologically passed to their children. To many scientists, epigenetics amounts to a heresy, calling into question the accepted view of the DNA sequence.

But epigenetics adds a whole new layer to genes beyond the DNA. It proposes a control system of 'switches' that turn genes on or off. It suggests that things people experience, like nutrition and stress, can control these switches and cause heritable effects in humans.

In a remote town in northern Sweden there is evidence for this radical idea. Lying in Överkalix's parish registries of births and deaths and its detailed harvest records is a secret that confounds traditional scientific thinking.

Marcus Pembrey, a Professor of Clinical Genetics at the Institute of Child Health in London, in collaboration with Swedish researcher Lars Olov Bygren, has found evidence in these records of an environmental effect being passed down the generations. They have shown that a famine at critical times in the lives of the grandparents can affect the life expectancy of the grandchildren.

This is the first evidence that an environmental effect can be inherited in humans.

In other independent groups around the world, the first hints that there is more to inheritance than just the genes are coming to light.

Click here for the complete BBC article.