Our DNA holds our secrets. It tells us where our ancestors came from, where we migrated to, and when, what people we mixed with, and how we adapted to whatever new environment – hot, cold, mountainous or low-lying – we found ourselves in.
The author – a scientist who directs the Human Evolutionary Genetics Unit at the Institut Pasteur – describes how DNA reveals the story of our species’ emergence in Africa, and our emigration out of there, 60,000 years ago, to all parts of the globe.
We learn about where we went, and who we mixed with and how this mixing provided our ancestors with the ability to survive deadly bacteria, and viruses, and have children that carried our protective genes.
The mixing and subsequent genetic diversity of humans is our great strength, the author says, and he tells of how a mutation in a gene picked up from mixing with archaic humans provides some of us with an increased ability to clear hepatitis C from our systems.
Alan Bennett’s Beckettian look at life in a care home; Irish links with Romanov Russia; bell hooks on girlhood
Hicky’s Bengal Gazette: How India’s possibly Irish first newspaper editor fell foul of its British rulers
Architectural Tales by Dominic Stevens: Imaginative reflections on the spaces we create, and the spaces in between
Poem of the Week: Secret Rivers
Sometimes, though, mixing can come at a price. A case in point the author presents here is the gene inherited from mixing with Neanderthals, which put people at greater risk of hospitalisation from the effects of Covid-19.
This book describes the grand genetic history of our species; our encounters with deadly bacteria and viruses and how these left their mark on our DNA, how this shaped us, and how it continues to do so to this day.
Genetic admixture – which is where two previously isolated populations interbreed – helped us adapt as we colonised the planet but it may have given us an Achilles heel – leaving us open to autoimmune diseases, allergies, hypertension and a propensity towards obesity. This may be the genetic price we paid to adapt.
A greater knowledge of our genetic past can help us unlock the information in our DNA that can lead us into a new era of personalised, precision medicine, the author says, where disease treatments are matched to our genes.
Something that is a disease risk to an individual, or group of people, may not be a significant risk to others. To better understand this, genetic studies need to become less focused on people of European origin, the author says, who make up only 16 per cent of the world’s population, but 78 per cent of all genetic studies.
