Genetic Control and the Mammalian Radiation
Organised by the Royal Society
Royal Society, 6-9 Carlton House Terrace, London SW1Y 5AG
Tuesday 4 November 2014
You and all the whales, rhinos and bats owe your lives to a tiny shrew.
A group of insect-eating mammals survived the inconveniently timed asteroid that slammed into what we now call Mexico, killing the dinosaurs. The shrews spread out, eventually adapting to all the niches abandoned by the extinct dinosaurs and converging on some of their tricks. Bats reinvented flying à la archaeopteryx, rhinos forged armour in the style of triceratops, whales ballooned like the plesiosaurs and you… perhaps you're unprecedented. Without the shrews, we might have no Sagrada Familia, no Shakespeare, no Justin Bieber. The world may well have been for the birds.
Dr Duncan Odom kicked off his Francis Crick Lecture - 'Genetic control and the mammalian radiation' - with this flourishing of mammals. The Royal Society awarded Dr Odom with this year's prize lecture for his work in a field of biology called comparative functional genomics. The Society described his research as 'pioneering'. It's certainly very cool, as I will attempt to explain.
Dr Odom claimed that these protein-coding regions of the genome are largely identical across all mammals. But not only do many species of mammal look different from one another, bits of any individual mammal look different from its other bits. The average mammal is made of over 500 different types of cell - neuron, sperm, skin and so on - some of which cluster into organs. So how can cells with the same genome become different organs doing different jobs? The answer, according to Dr Odom, lies in gene regulation.
Explaining this was going to be an epic undertaking. Dr Odom's gentle American voice helped pace the heavy material. He was well aware of the giants upon whose shoulders his work stood. In ten slides, he summarised 40 years of research – sweeping over six to eight Nobel prizes as he did so. Countless hours of research were summarised in a sentence.
Gene regulation controls when and where proteins are made. This means that sections of the genome regulating the expression of genes might be key to understanding the diversity of mammals.
Proteins called transcription factors stick on to sections of the genome known as enhancer regions. Together, enhancers and transcription factors switch genes on and off. This is where Dr Odom's work comes in. His lab compares the enhancer regions across distantly related mammals, looking at where they differ and which genes they affect. Comparative functional genomics. This mapping of enhancers, he said, shows the pathways of evolution.
The lecture was a whirlwind tour of cutting-edge, big-picture science, fully deserving a place on the Royal Society's stage. Dr Odom looked the part in a shiny velvet jacket, black open-necked shirt and shaved dome, like a cyberpunk scientist.
I can't say I came away from the lecture with a full understanding of what went on, but the core topic - enhancer regions - were new to me. Saying that, I'll be more than happy to watch the whole lecture again when The Royal Society uploads the video.
The lecture ended with a plea to the audience. We humans are causing the planet's sixth major species extinction. The last members of too many species have died by human hands. Dr Odom urged us to do something: stop whaling, ban the bushmeat trade.
I broadly agree but want to take issue with his simplistic argument. Efforts to stop the bushmeat trade have seen national parks plonked on the land of indigenous people, patrolled by anti-poaching squads. The parks can end up displacing these people who, no longer able to feed themselves from the forest, sometimes turn to the bushmeat trade in order to stay alive. Hunter-gatherers are suddenly treated as poachers and, according to UK-based NGO Survival International, are 'abused' by the squads. Forest-dwelling people, already marginalised, become further exploited and criminalised.
Dr Odom framed his plea with the phrase, 'humanity must grow up'. That, to me, involves having grown-up debates where we attempt to understand the nuances and the histories of a situation. Genetics is complicated but so is the world, and sloganeering could have dangerous consequences.