Unlocking the ancient code

[Judi Lynn]

PETER FORBES
30 May 2018

David Reich’s pioneering study of ancient DNA might have caused some ructions among social scientists – but it’s set to revolutionise our ideas about human migration and identity, reports Peter Forbes.

The study of prehistory – roughly everything before 5,000 years ago – began by grubbing in the earth for the remains of settlements and goods and bones and fossils. Before that, there was the geological record with a time frame crudely assessed by comparing strata and estimating sedimentation rates. All this changed with radioactive dating, invented by the great physicist Ernest Rutherford in 1905. First, it impacted geology, giving us an accurate time frame for the history of the earth, and then for the fossil record of early Homo sapiens, now dated to around 300,000 years ago. In 1949 came radiocarbon dating, which gives us a date for when living things died. Although it is effective for only up to 50,000 years, it revolutionised the study of the more recent past. Archaeologists had dates for their settlements, pots and ancient human samples.

Now, scientists can analyse ancient DNA – which is where David Reich comes in. A Harvard geneticist, Reich’s pioneering work is rewriting human prehistory. His book Who We Are and How We Got Here1 contains startling new findings across the whole period of human evolution, heralding a new era of human understanding of our own place in the world. Reich is an urbane and affable 45-year-old, the model of the modern professor. History was his first passion; he started with social studies at Harvard, switched to physics, then began but didn’t finish a PhD in biochemistry at Oxford. He was clearly searching for something. All these disciplines suddenly added up when he began to work in medical genetics and then in ancient genetics.

Ancient DNA studies began around 20 years ago, but the field was small. Sequencing was slow and expensive, the samples – from small quantities found in well-preserved specimens – were few, and they were hard to purify after thousands of years of contamination by bacteria. After an ‘apprenticeship’ with ancient DNA pioneer Svante Pääbo at Leipzig in 2007, Reich set up his own lab at Harvard in 2013, where he created a ‘genomics factory’, industrialising the analysing process and sequencing hundreds of samples in a single study. Reich works with large collaborative teams across global universities but he is the acknowledged leader. In 2015 he was named by Nature magazine as one of 10 scientists of the year.

More:
https://www.eurozine.com/unlocking-ancient-code/

[saidsimplesimon]

1. Genetics is a fascinating discipline for

scientists. My best friend, deceased now, obtained a dual doctorate in genetics and psychology in order to help those who suffered from addiction and other mental issues. We need to better fund scientific health research at our universities instead of weapons, robots and psych ops, imo.

[bobbieinok]

2. Thanks for post.very interesting article. Noted the books that influenced him.