 Hello and welcome to NewsClick. This is our science show when we discuss what we select as one interesting development in science and talk about it. This week we are going to look at something which has been of recurring interest to NewsClick, which is looking at archaeogenetics and what could be a major instrument of further discoveries. One of the problems in archaeogenetics which is really means that looking at your genetic material but from essentially archaeological finds, old bones in other words is what we have been looking at and then to find some material, genetic material which can be amplified and which can then be understood to give you who were these people, what were the lineages, where did they come from, who were their forefathers and what are the further descendants of this population. A kind of ancient population genetics seem to win. Of course in current times in India that also becomes political because the minute you start talking about that this the Indian subcontinent had people coming from outside immediately causes an uproar particularly by certain sections who believe that we the current stock of people have been always here. Now as we know the modern scientific knowledge makes it very clear that all human population the descendant of an ancient African population that we are in fact non-resident Indians. So that's not open to question. Nobody who has any smattering of scientific knowledge to do with question. The question is that if we look at population migration, population shifting from one place to another that we have been dependent for this and we have had, we have presented the steps, migrations, we have presented the Neolithic migrations in our discussions in science news click. So this all has been taken from very small samples. The number of such samples are really sparse and therefore though we have built from the samples we have, we have built a fairly interesting history of how previous migrations have taken place but they have been punctuated with large gaps. Now one particular approach which seems to be much more likely to bear fruit in terms of giving us much larger number of samples is looking at not at the what would be the genetic material in our bones, ancient bones but actually looking at the sediment that means on the cave floor what is deposited. Now why would that leave us or give us genetic material? After all we can understand if there is genetic material still left over from the bones which are 100,000 years old, we can understand that yes okay some genetic material may be left over particularly there is a bone in the year which seems to have a very thick, it seems to be a very thick enclosed, more mitigate encloses some genetic material and that has been used widely to take out samples and then amplify it and then see what it is. Now why should the cave floor give us genetic material and that of course is obvious if you think of how we live if you have babies in the house as one of the researchers said the poop and if the poop there is some genetic material which is there and that that is something which in the cave floor would accumulate over a period of time. Then of course you also are cutting up things you are also hammering things you might also bleed. So a certain amount of material deposits over time and if you have this large number of people spanning maybe hundreds thousands of years staying on caves then the sediment layers that form that can actually give you if we can amplify it if we can isolate the human DNA from it then it gives you a much richer information than we can get from the bones. So while earlier we have had mitochondrial DNA which is basically what we get from our mother's side some amount of mitochondrial DNA from sediments of this kind we have not been able to get what is called the nuclear genetic material which is something which is the nucleus of the human cell and that has much richer genetic material than the mitochondrial DNA has. So that of course that genetic material we get both from the mother and the father so don't start thinking the mother's only give us mitochondrial DNA so this is from both the parents. So when you look at this genetic material the nuclear genetic material then the history that it unfolds is much richer we can check the lineages and we can see where they came from what is the variability if we have a larger set of nuclear genetic material from the floor sediments and therefore you can probably have a much richer history then we would get from the few samples that we have been able to get from the bones. Till now we have got genetic material from 18 Neanderthal population if you look at the Neanderthal population that of course is researched a little more mainly because it's Europe there's more archaeological work going on over there and plus colder climate so the chances of preserving the genetic material in the bones is a little better if we take for instance the Indus Valley which is hot then the genetic material tends to disintegrate much faster in hot climates hot temperatures therefore that has been relatively less likely to produce genetic material. In this particular case though this 18 individuals the genetic material we did get from the bones the nuclear DNA the current research and that's been done by again as all this it happens in modern research not by one of two people by a large team I think it's about 35 or 36 from different countries who've come together and done this research to see how you can take traces of this genetic material separated from animals others that might be there and then also amplified see what is really there. So this is a complex work and obviously it needs a variety of skills but the breakthrough here and that's why we are discussing it not what specific results have come through because of this they're interesting but that is by itself not the major issue it's at a huge new avenue of research has opened up for archaeogenetics population research in archaeogenetics and migration of people. So we have now an alternate to finding only genetic material from bones and being able to look at perhaps a much richer picture in the future because we would then look at the caves where human habitation has been there and you know there are very large number of caves from South Africa to South Asia to anywhere in the world caves where the national habitat of ancient humans because that's where they would hide at night in order not to be attacked by big animals. So therefore the caves is where the initial habitat of a lot of the ancient human population was. So given that there is the floor sediments now which we can perhaps look at and see which of them leaders generating material. Very quickly the research on this particular set of materials and this has been done in three sites we'll show you the picture just to be second. The three sites are really one is in Spain and two are in Altai mountains. So what we find is that initially there were more lineages of Neanderthals and after a certain time one lineage becomes much more dominant and other traces other simply disappear that is in the small segment of DNA that we have found that has been looked at. So it does seem to also bear out what is also what we see in Africa for instance that after a certain variety which is available in Asia it's some some lineages become dominant and others seem to disappear. So it seems to bear out what we see in other places as well. Some of it could be simply to do with the fact that there is a climatic change and therefore certain groups survive certain groups don't and the groups that survive because they're essentially there is what will be called smaller number of people who survive and therefore it becomes more homogeneous than the earlier population that we saw. So these are some things we'll have to tease out as we go. What is most exciting about this and that's why we're discussing it is the fact that this is something which is giving us opening out for us a completely new terrain that is looking at sediments on cave floors getting genetic material from it and from that to construct the archaeological history of populations and their migrations. This is all the time we have for NewsClick today. Do keep watching NewsClick and do visit our website.