Today I’m talking to Jonathan Pettitt about what makes humans and his research unique. To hear more from Jonathan join him for his show ‘May Contain Neanderthal’ on the 25th August at the New Town Theatre.
What is the unique angle of your research?
My research is focussed on the study of nematode (roundworm) genetics; specifically on the genes that are unique to nematodes. The practical reason for this approach is that the products of such genes may make good targets for drugs to treat nematode infections in humans, animals and plants. However, I am also interested in how new genes evolve and how they become incorporated into existing genetic networks without catastrophically breaking them.
The great thing about genetics is that apart from a few idiosyncrasies, worm genetics is the same as human genetics. In many ways human genetics is pretty unremarkable (nematodes are much more successful than mammals, for instance), but I’m fascinated by what genetics can tell us about ourselves, where we come from, and possibly our future as a species.
You say that the statement “our genes make us who we are” is false, are we not unique? Does our DNA not make us special or different?
Obviously, in one sense, we are human because we have a human genetic program rather than that of a gorilla, a nematode, or a carrot. But that simple answer hides a wealth of ignorance.
There is not a simple connection between each person’s genetic make-up and their characteristics. Our genome is not a blueprint, but more like a cake recipe, or a set of origami instructions. There are 20,000 or so human genes, and each gene exists in different versions, some of which have no effect on gene activity, others have very strong effects; most gene variants have very small effects on human traits.
Building a human is a complicated business: the trillions of cells must organise themselves guided mainly by their genetic instructions, but also in many cases by their neighbours. Many cells will not perfectly execute their genetic code, which is why identical twins are not the same, and why no one is completely symmetrical: the same genetic program is running in all our cells, but chance events will shape the interpretation of this code in each case. You are unique, but only part of the reason for that is genetic.
You also mention the prospect of designer babies; will they be here anytime soon? If not, should we even be doing research into them at all since they seem the idea of human uniqueness and individuality?
Short answer to the first question – no. Our understanding of human genetics is not sophisticated enough to do anything other than make corrections to single damaged genes. And we already achieve the same outcome using preimplantation genetic diagnosis to prevent serious genetic diseases from being passed to the next generation.
Research into the genome engineering of human embryos is very tightly controlled and is largely focussed on improving our understanding human embryonic development and fertility.
There are still technical challenges associated with genome engineering technology that need to be overcome. However, I think it is almost inevitable that the technology will one day be used to improve human biology – disease resistance comes to mind, or tolerance for extreme environmental conditions. It is worth bearing in mind that evolution has already done this multiple times in the last ten thousand years in different human populations.
What will make your CODI show unique?
At the beginning of the show I want to find out people’s views of the role played by genetics in “hot button” human traits like aggression, IQ and sexuality. I will be guided by these responses in determining the direction of the rest of the show.
I also want to get across to the audience that our ignorance about how genes work to build a human (or a worm) is enormous – what we understand is dwarfed by what we don’t understand. To help with this, I’ll be bring along a scale model of the human genome.
It’s important for people to realise that making meaningful predictions from someone’s genetic code is still a long way off and may never be fully realised.
What’s something unique about you?
At the beginning of my career in genetics, as a PhD student, I genuinely had doubts about whether I was doing the right thing, because of Gandalf from the Lord of Rings.
Experimental genetics (working with yeast, fruit flies, or worms) involves working out how genes function by systematically breaking them, and then seeing what happens to the organism with the broken gene.
At the beginning of my PhD, I was reading The Fellowship of the Ring for the first time; there is a scene in The Fellowship of the Ring where Gandalf chastises Saruman, saying, “He that breaks a thing, to find out what it is, has left the path of wisdom.”
When I read that, I seriously reconsidered whether I would, in fact, end up leaving the path of wisdom if I pursued a career in worm genetics. In the end, the lure of deciphering how genes work overcame any qualms I had about leaving the path of the wise. So, I guess I’m probably more Saruman than Gandalf.