Who We Are and How We Got Here

A book of two halves.

A New Tool

The first, is a treat. Rapid scientific advance has seen ancient DNA emerge with a bang. This should be hailed as one of the most exciting scientific developments of our time

Telescopes, microscopes and other tools give us access to new worlds. With them many celebrated discoveries can be made. Advances in these tools allow us to see further and deeper.

But how rare is it to get a brand new category of tool. A new way to push back the boundaries of the unknown and unlock parts of the universe that previously were off limits.

We cheered the discovery of gravitational waves. A new tool to peer at the stars and see further and deeper into time and space between the stars.

This book is about a tool of similar magnitude that seems lesser known. Ancient DNA and the study of population genetics have allowed us to gaze into the fabric of our cells, and into the deep past of long dead humans.

Before this, our knowledge of the past was limited to the surface of the world. Hoping that bones brought to the surface by geology were caught for study before they were destroyed by weather.

Now we know of peoples for who there are no bones, no archeology and no histories. We can now see the ghosts of the ong dead in our own cells.

It is an exciting thing to be alive to witness.

The first half, captures that excitement. I started underlining points of interest only to stop after a they nearly joined to cover entire pages.

The complexity of biological heredity, the astonishing advance of the technology and decline in its cost, the ghostly silhouettes populations and drama of sudden changes in the genetic record. Our discovery that we carry Neanderthal DNA as well as from illusive Denisovians.

The work pays moving homage to Luca Cavalli-Sforza, placing his work as ahead of its time, foundational and now fully realised with the emergence of modern genetics and ancient DNA.

This is a beginning. One which should greatly advance our understanding of ourselves.

And here the controversy begins.

But for whose benefit?

The longest section on this book’s Wikipeida summarises how it was received. Critics seem to have universally praised the books science and communication of it.

This issue appears as the second half turns to how these new tools should be used, the conclusions we can draw and the impact of the work in mainstream culture.

Racism is foundational to population genetics - a pursuit for scientific basis to legitimise the supremacy of European stock.

However, the finding that there is more difference internal to populations grouped as “races” than between them seemed an insoluble challenge to the scientifically minded bigot.

These histories hang over parts of the book that discuss the structure of populations. In one case asking if flight from this past has left us ignoring differences that verifiably exist between populations:

For the great majority of traits, there is, as Lewontin said, much more variation within populations than across populations. This means that individuals with extreme high or low values of the great majority of traits can occur in any population. But it does not preclude the existence of subtler, average differences in traits across populations. (p 255)

This has reignited a debate around how discussion of “populations” here may, or may not, map on to discussions of race. With uncomfortable parallels proposed between this discussion and racist scientific histories.

There is also the question of participation.

Population genetics is requires enormous amounts of data. The most diverse and numerous the sources the better the chances to make new associations. The dat we have currently skews to the north and west due to the historic cost, healthcare development and where funding and interest focused.

Ancient DNA also has a skew, to colder, dryer climates with better preservation and that are still above sea level, again somewhat northerly.

In some places this paucity of data places a large emphasis on a few existing ancient remains. Or creates a desire to go out and fill in gaps from modern populations.

And there is reason to be impatient. Not only could this research tell us more about our origins and pasts, but it could also unlock medical breakthroughs by better understanding our genetics at scale.

I can believe there is a deeply progressive cause here.

So with such urgency what do you do if folks resist this drive to data? What do you do when indigenious populations refuse access to ancestral bones that could key keystones of DNA? What do you do if modern populations say they already have an origin story and have little interest donating DNA to an attempt by distant people to provide a overriding new one?

Perhaps more troubling, given the results redefine geographic origin - what when the results appear to validate population difference that map to racist concerns that have been the basis for discrimination?

At times the author seems frustrated by some of these concerns. Especially with ancient remains claimed by indigenous American groups. His more fierce critics place his response somewhere between naïve and ethnically negligent in his desire to forge ahead without addressing the histories of exploitation that surround populations of proposed subjects.

I am still working out what to think about all this, and suspect there’s a great deal of historical context I miss as a lay reader in the field.

I worry that this could get characterised as a camp who would frustrate great scientific discoveries, and a camp who would trample the desires and beliefs of those less powerful to achieve them.

But in the reviews I read I think there is room to see this as a call for “less haste, more speed”, and a well intentioned debate about the proper use of this new tool and gathering data to feed it. Continuing questions of research ethics that I assume are very familiar across scientific campuses.

At the end of his book review “Ghosts in the Genome” John Hawks acknowledges the advance of the science whilst pointing out that the output of these studies is not merely more papers for the academic mountain. Ancient DNA and modern population genetics offers us a new window into the story of human origins:

But for the great human story to matter to us, we must each see our own place in it. The dead cannot speak, but science can help us to see their humanity nonetheless. Doing so helps us maintain the humanity of our science.

One of the most thought provoking books I read in 2020, I look forward to seeing where this all takes us, what discoveries we make and how the rest of us respond.

| Huw

After "Who We Are and How We Got Here" I read: The Peregrine

Before "Who We Are and How We Got Here" I read: Life on Earth