As we learn more and more about the genes that control human characteristics we're getting tremendous opportunities, we're also facing important choices that will affect the future of our species. This kit here for example is already being used to prepare human embryos for selection for selection to avoid serious genetic disease, but we can now think about going even further, we can think about altering those embryos in an active way, we can think about perhaps getting better disease resistance, increase our intelligence, altering our appearance if, and there's a very big if, we wanted to.

We're taking the reins of evolution more and more into our own hands but it's been actually a long time that we've been doing this already. These guys started their journey of selection a thousand, several thousand years ago from wolves we don't exactly know how wolves began to be domesticated by man but we can guess that some of the er more timid ones might have hung around the camp site or maybe we killed parents and took kids, little wolves into captivity and they probably as dogs do respected us as pack leaders and this helped the relationship, certainly the relationship between humans and dogs has been enormously successful. And from that time on people began to breed for characteristics. This little chap I was surprised to find out is actually not just a toy but it's actually a lean mean hunting machine because his job and the reason he was bred with tiny legs is to go down burrows and chase rabbits. This one on the other hands is a big fast running guard dog from Afghanistan and he is obviously much more powerful and has been bred in entirely different way. He's also acquired now this nice silky coat as a show animal so er breeding also for appearance as well as the original purpose. And as you know there's lots and lots of dogs and they do have a tremendous variety of the characteristics, probably they were there already in the original wolf population, it's unlikely there being that many mutations it was more a matter of combining characteristics that were there before.

But we'll take these guys back here, thanks very much indeed, well done dogs they're lovely aren't they. But we also want to think about one particularly human characteristic just to illustrate one that you perhaps don't know about and we have some people to come in here please. This is about a gene called ACE, ACE and it's function is to control aspects of the blood supply to the tissues and also the way oxygen is taken up and it comes in two sorts. It comes in a sort that actually keeps the blood vessels wide open and then it comes in a sort which is like most of us have where we shut, tend to shut these things down when we're just moving around. Now what it means is actually that the first sort which keeps everything wide open and going well gives people much great endurance and this line up here includes one person who is the youngest person to climb all 7 major peaks on the 7 continents and has also, so he's got to the top of Everest and is a tremendously vigorous climber the other two are not at all like that and I want you to see if you can guess, if you think that A, is the vigorous climber hold up your green cards, if you think not, hold up the red. Oh not many for A, how about B who thinks B is the one, hold up the greens. They can't guess can they, unless you think it's C, who thinks it's C, green cards for C. Well it's quite a mix, I think actually A possibly got slightly more, so will the right one step forward, who is the real one?

So there you are, well done greens you've got it and er thanks very much for coming along, we should congratulate you on your tremendous feat of what you've done, thank you, but it's partly down to the particular variety of the ACE gene which you have which gives you the ability to endure more than average, much more. Thank you very much.

So these are, these are genes that are generally in the population but we have of course now the ability to take pieces of DNA and join them together, that means that we can in principle and to increasing extent in practice hook up bits of DNA from one species and get them into another. I'd just like to show you one apparatus that does this for us and this is a gene gun. This is used for getting foreign genes into plants and the way it works is that a suspension of gold particles coated with DNA and then fired physically into plant cells. We're going to put a piece of filter in there so we can just see where the particles go like that. And then we turn on the vacuum and remove the air from the chamber I'd like to have somebody to volunteer to come down and er fire the gun. Who would like to fire the gun. Right well one I say the pressure's more or less gone down now so if you can, you can fire, press the, don't, don't lean over if you can't see, that's it there you go.

So there we are he did it and if you were lucky you may have seen the orange splodge of gold particles appear on that filter, there we are can you see that little pattern. Now in reality what we would do is to have some embryos like this like these underneath that, that erm gun and they would fire the particles of DNA in. This is a good way for putting genes into plant cells because they have very rigid walls and it's difficult to get other things through, thanks very much indeed. So we can see how we can we've been manipulating genes, these few examples show that we are very interested in doing this we've been doing this for a long time in other organisms but what about us. Obviously it's immediately begins one to think well maybe we can improve our condition in some way by doing this and the first thing we're going to look at here is what we call gene therapy. This is a baby in Paris which is suffering from a very severe immune deficiency which is due to a defect on the X chromosome. And what people have found is that by taking marrow from the baby's hips about a 100 mls a huge amount I was amazed how much gets taken out and shaking it up to release the cells and then culturing them and you'll see in a moment how they are grown and then infected with a virus which carries into the cells the gene.

There they are manipulating the cells in the sterile conditions to introduce a virus that carries the missing gene into those bone marrow cells. Now the reason it's a bone marrow is that those are the cells that produce the blood cells which circulate and among those are the cells which are required for the immune response. And this is actually the first successful example of gene therapy in which there really has been in a number of patients now a complete cure. What they're doing is to alter the body of the baby after it's born and repopulate the marrow with these cells. But that doesn't work in quite a lot of cases, people are trying are more, there will be more successful cases of gene therapy in the future but at the moment er this is, this is the best one. The difficulty is to deliver cells to the right place to carry them in it's easier with the blood where cells are circulating anyway to carry them into the proper place and get them to work all the time is proving very hard. But it will, there will be more and more successes in the future, but inevitably people come back to thinking about what could be done earlier on, would it be good to to look at embryos and do something there.

And so this story now goes back to nearly over 20 years ago the history of invitro fertilisation, it's a method that was developed to allow certain sorts of infertile people to have children when they wouldn't otherwise be able and what it consists of is getting a set of eggs from the mother the future mother and sperm from the father and bringing them together invitro, it means outside the body in a dish that this is done. And Alpesh Doshi is here to show how it's done, thank you, Alpesh.