How Early Farming and Genetic Manipulation Shaped Human Civilization

Scientists throughout the world have been debating the power of gene editing and particularly its potential to change the genetic sequence of a human for eternity. Biologists, ethicists, lawyers, regulators and politicians have been working together, trying to explore the implications of these new tools, and to develop frameworks for making sure they are used well, in a responsible way.

Current evidence suggests that farming started in the region known as the Fertile Crescent, around 12,000 years ago. Multiple groups of people from different genetic backgrounds seem to have been farming independently in the area that now includes modern Palestine, Iraq, Jordan, Israel, western Iran, south-eastern Turkey, and Syria. The shift from a nomadic hunter-gatherer existence to agricultural settlements was probably a gradual one, but it depended absolutely on the human ability to tinker.

Humans began to select the largest grains, the most prolific legumes, and to plant these selectively. Repeating this process over multiple growing seasons led to the development of nutritious harvests, and the selection of many of the crops on which we depend today.

These early farmers didn’t just change the development of plants. They also selectively bred animals for traits that were useful, from the milk and meat production of cattle, sheep and goats to the tractability and companionability of horses and dogs. The consequences of creating food sources that allowed populations to remain in one place were profound. Settlements grew in size, and complexity.

Social hierarchies were reinforced and maintained, and systems such as writing developed multiple times, as rulers sought to monitor and control systems and populations. The increase in production, and the ability to store surplus food in times of plenty, allowed societies to develop where individuals could specialize and with this came a huge increase in the production of cultural artifacts.

It’s remarkable to consider that almost all human activity – glorious or disastrous and everything in between – has been built because we have learnt how to hack the genetic material of other organisms. By selecting individuals with traits we considered useful or appealing, we changed the evolutionary paths of living species.

DNA is the genetic material of almost all organisms. The acronym stands for deoxyribose nucleic acid, which is a bit of a mouthful. A helpful way to think of DNA is as a written text like a script or a book. Any written text is made up of letters from an alphabet. In the case of DNA, the alphabet contains only four ‘letters’ called A, C, G and T. Technically, these are referred to as bases, but ‘letters’ probably serves our purpose better here.

All humans are far more similar to each other in our genetic scripts than we are to other species. The sequence of letters in human DNA is different from in other organisms and the differences become more pronounced the further back we have to go in evolutionary history to find a common ancestor. If we compare the sequence of DNA letters between humans and chimpanzees, they are about 98.8% similar.

It was extremely difficult, costly and time-consuming to use the original techniques to make changes to just one letter in a complex genome. It was even more difficult to simultaneously change a few letters at different positions in a genetic book. But being able to do this is vital if we want to explore how some of the 10 million variable letters in the human genome work together to affect our lives.

Source – Hacking the Code of Life: How gene editing will rewrite our futures by Nessa Carey

Goodreads – https://www.goodreads.com/book/show/43359681-hacking-the-code-of-life