Human Fruit Flies

Huw Lemmey


"No man is an island. No woman is an island. It's clear now that no island is an island" begins geneticist Steve Jones in his talk, the last of four from physical scientists tackling different ideas of extinction. Jones' talk focused on human populations and genetic diversity. "Shake hands with your neighbour", Jones asked. "Congratulations! For about 50% of you. I've just introduced you to your sixth cousin". In Western Europe, around 50% of people are related by a shared ancestor who lived around the time that Darwin published "On the Origin of Species". All people, in fact, share a common ancestor just 4000 years ago; about the time, incidentally, of the biblical existence of Adam and Eve. But that, Jones explains, is another story — one of many raised and left hanging throughout his talk.

Jones has devoted his career to the genetic story of the snail and the fruit fly — a good specimen for geneticists due to its short lifespan and quick breeding cycle. Occasionally, he says, he's lowered himself to studying the human, and in terms of studying genetics, the european Royal Families are the human versions of fruit flies, due to their often extreme levels of inbreeding.

Take Alfonso XII of Spain; it would be normal that, if you traced his ancestry back 7 generations, you'd find he had around 172 ancestors. In reality, he had just 8.

Another good way to explore genetic diversity in populations in Western Europe is by examining surname diversity — Britain, for example, has a strong tradition of patrilineal surnames, with a father's name passing down to his children. Jones examines the below map from UCL, showing surname diversity in the UK in 2010.


He also examines maps showing the spread of his surname from the late 19th Century to today, as populations spread and the surname escapes its traditional boundaries in North Wales. Meanwhile, whilst the mean number of people per surname in the NYC phonebook is 2 1/2, in Oslo it's 60. What do these examples show? Well, that we're inverting the genetic history of humanity; whilst we spent thousands of years spreading into discrete populations becoming increasingly inbred, today we're mixing, and our genetic makeup becoming ever more diverse.

On those stories raised, then postponed for another time, though; Jones began his talk by referring to "so-called races… There are no races", but ended with an example of children borne of "white" mothers and "afro-carribean" children, passed over without further clarification or qualification. The subject of the use and ideological framing of science in society was raised in the discussion with Chiara Marletto, Helena Cronin, Jennifer Jacquet, John Brockman and Molly Crockett. Cronin, whose talk examined biological sex differences which she claimed explained and justified, for example, the huge discrepancy between men and women in engineering or the caring professions, spoke out against what she saw as the imposition of "ideology" into the empiricist field of physical scientists, denouncing a somewhat nebulous "orthodoxy" never adequately defined. Jones went some way to supporting that, conflating those who oppose evolution outright with those who are critical of evolutionary psychology as both indulging in obscurantism; as if evolutionary psychology isn't a hugely contested field which is constantly instrumentalised to justify things like — well, the gender pay gap or gender essentialism.

"Science stands by itself." Jones claimed. "It doesn't care what people think about it. The universe didn't care about the inquisition, it carried on turning. The same is true with genetics". The universe, of course, is a thing with very different properties from science, a field of human study. Besides, claiming the purely empirical, non-ideological function of science in astrophysics is somewhat easier than in the fields of genetics or gender variance. Jacquet, whose fascinating work deals with attempting to change behaviours regarding the conspicuous consumption of shark fin soup at weddings within the Chinese community in Canada, quite rightly called out the idea that science can ever exist outside an ideological framework. "Every discipline has its own indoctrination process into the way the world is", she said, pointing out that in her experience physical sciences are often less willing to take account of changing contexts than their colleagues in the social sciences. Sadly, the debate ended just as this important split was raised.