Populating Ice Age America: Q&A with David Meltzer

[Music] hello everyone and welcome to our webinar populating ice age america with david meltzer i'm beatrice rael i'm the archaeology editor at cambridge university press and i've had the pleasure to work with david on the second edition of his book first peoples in a new world populating ice age america which is publishing this summer david is here today to tell you about his book and answer your questions on prehistoric north america throughout the webinar i'd like to invite you to submit your questions using the q and a button that you will find on the toolbar at the bottom of the screen i'll read out your questions to david and i also will be asking a few questions of my own but first i would like to introduce david who is the henderson morrison professor of pre-history at southern mesa methodist university he researches the origins antiquity and adaptations of the first americans and paleo indians who colonized the north american continent at the end of the ice age david focuses on how these hunter-gatherers met the challenges of moving across and adapting to the vast ecologically diverse landscape of late glacial north america during a time of significant climate change his archaeological and historical research has been supported by grants from the national geographic society the national science foundation and the potts and sibley uh foundation and the smithsonian institution so now i'm going to turn it over to david happy to chat with you today beatrice about the new book um let me say a few things about the book just to get us started here the uh first edition was published in 2009 and i have to say it it did very well reviewers were kind people bought the book but it quickly became obsolete uh in chunks of it and i was i had sort of for i could foresee on the horizon that there were changes coming in this area of research and i could anticipate those changes but i didn't anticipate them quite well enough that i got everything in and specifically what was happening was there was a revolution going on and the revolution was the ability to acquire and sequence dna genetic material from ancient remains i knew this was coming i could see it on the horizon but when the book came out it was still a few years away in the decade or so since the book first came out there's been a huge number of developments that the ability to acquire and sequence ancient dna is perhaps the most important but there were quite a few others and so um when it came time to kind of rethink the book i thought okay um a decade has passed uh we've learned a tremendous amount in just these last 10 years there have been new sites found we have a better understanding of the larger context of the peopling of the world and where the people in the americas fits in we've learned a great deal more about the landscape that they traversed the routes they took to get here uh how they expanded across the continent and so it was high time to bring out the new edition and that's going to happen well i've got the page proofs on my desk uh that will happen in just a month or so you're you're muted yeah what's the single most important discovery that was made that really made you that pushed you to just decide so that it was time to do a second edition it really was the dna you know i've been very fortunate that um i got involved fairly early uh in a lot of this research collaborating with esky willerslab at the center for geogenetics in copenhagen and over the last well let me sort of frame this up chronologically the very first ancient genome was published in 2010 there were actually a series of them that came out the first ancient uh north american genome an ancient genetic sequence uh was published in 2014 since then there have been um quite a few that have been published and they've completely changed our view of the peopling of the americas and i should explain why that is i'm an archaeologist and with archaeology you can do a lot of things you can determine the the timing uh by which people uh came into the americas you can learn something about their adaptations you can learn how they responded to environmental challenges you could see how quickly they moved across the landscape but the one thing archaeology has never been very good at is population history how do these ancient people relate to present-day people how do present-day people relate to ancient peoples has there been admixture between groups over time who are these groups where did they come from um what do we know about the source populations these are questions that archaeology was never really poised to answer what we have with the archaeological record are sort of snapshots of sites and artifacts and while we can make certain assumptions and certain inferences about how archaeological material over here is related archaeological material over there we're never quite sure if we're right and more than likely we're wrong with with ancient dna we are able to sort of link these different populations in a way that we never could so it's not so much replacing archaeological knowledge as it's really enhancing it and supplementing it with in really important ways so with the genetics what we've been able to do is get a much more nuanced and detailed picture of the whole peopling process who was related to who how fast they moved across the landscape be able to say in this part of the country we've got long periods of continuity over time whereas in other areas we've had populations sort of coming and going so we're seeing things we could never see before and that's really what what drove uh the new edition this fundamentally changes how archaeologists work then yeah yeah i mean i'm still going out in the field this summer but you know look this is a question that's fundamentally interdisciplinary and i've i've always been well i've never paid much attention to disciplinary boundaries um because these are kinds of questions that you need geology uh you need to understand skeletal anatomy you need genetics and so um we're we're really at a point where a lot of these disciplines are converging and converging in a way that is suggesting that we might actually be close to answering some questions that we've been trying to answer for oh a century a century and a half in terms of you know who were the first americans when did they get here how did they get here uh and with all of these converging lines of evidence we're starting to get a pretty good picture of of um that whole process could you give us an example of a site where you're getting consistent and converging results from different types of evidence well okay so um timing the issue of timing with archaeology you always know the point by which people have arrived okay so if you've got say a fifteen thousand year old site you know that people have been in the americas for fifteen 000 years at least but you're never going to find the very first footprints the very first archaeological site that was ever created in north america right i mean the odds are infant testing small that you would so you know people got here before you actually see them archaeologically i've used the phrase you know they're they're here but they're below archaeological radar probably for centuries and millennia before they're starting to produce enough sites that we are fortunate enough to discover to know okay yeah they're here for sure so with archaeology we have a minimum age of when people got to the americas it's by at least 15 000. with genetics we actually have a maximum age because what genetics provides us with is the timing by which ancestral native americans split off from their northeast asian populations and started to head to the americas so we know and this is again one of the things that we we never would have been able to know before we know now by virtue of the genetic record that northeast asians and ancestral native americans diverged from one another one group staying in northeast asia another group coming across the bering strait in the bering land bridge around say 23 000 years ago so we now have about an 8 000 year window within which we know that process must have taken place and so the question is you know when within that 8 000 or so year window well then we turn to things like the glacial geological record we turn to the records that we have from paleoclimates and paleo environments and we can see that okay from the period from about 23 000 to about 19 000 years ago you're in the coldest depths of the ice age people probably weren't doing a lot of moving around on the landscape they were probably hunkering down in refugia areas that were sort of milder uh if you can talk about sort of being in the midst of an ice age and finding a mild place to live right so there probably wasn't a lot of cross-bearing straight traffic at that point but we know now that around 16 000 or so years ago we start to see other species moving we start to see elk we start to see moose crossing over into the americas from northeast asia so by and and what that would suggest is that okay the climate and the environment is getting such it's warming enough we're coming out of the grip of the ice age it's getting warmer enough that other species are moving there's a pretty good chance humans are moving at the same time it doesn't mean they couldn't have come earlier but it does suggest that these are conditions under which it would have been good to be moving so again all of these things when you sort of pull together all these different threads you get a really nice uh tapestry that starts to come together um still a lot of questions to answer um but we're basically a whole lot further on than we were just a decade ago when the first edition of first peoples came out really impressive um how can geological evidence be effectively used in the studies you've touched on that in your in your answer but perhaps you could expand on that sure so north america during the depths of the ice age was a fundamentally different place than it is today you had two massive ice sheets basically covering canada they went from newfoundland all the way to the coast of british columbia okay they were um upwards of three and a half kilometers thick and they extended from basically north of the arctic circle down to well central ohio right these are massive massive ice sheets when those ice sheets are in place um i'm getting into teaching mode so i'm waving my arms and i realize that it seems kind of threatening to do that to the camera i apologize to viewers out there i'll try and control this a little bit better um he talks with his hands i'm sorry so um we know that when you've got these massive ice sheets they're basically going to be blocking the routes into the americas because once you get into alaska during the depths of the ice age it's a cul-de-sac it's a dead end because you've got these two massive ice sheets south of you between you and north america south of them south of the ice sheets sort of the lower 48 as we would say here in america right so we need to know the timing of glacial advances we need to know the timing of glacial retreats in order to understand what routes would have been opened and when and we know that there were basically two ways of getting from alaska down to the lower 48 at the end of the pleistocene one was down the coast and the other was down what's known as the ice free corridor which opened up between these two ice sheets down along the sort of eastern flank of the rocky mountains one of the other things that we've learned in just the last 10 years and again it's because of ancient dna we have a much better handle on when these routes were open so the geological record uh along the pacific coast gives us a pretty straightforward record of ice retreat and when the coast was clear as it were the interior ice free corridor has always been a bit of a puzzle because we know that as the ice sheets began to melt and move apart from one another and this corridor opens up between them initially it's going to be a pretty tough place to be because when the ice sheets retreat they're going to leave behind just lakes massive mud flats it's going to be cold there's not a whole lot growing out there so it's kind of a two separate questions when does the ice retreat far enough that you physically have a passageway between alaska in the lower 48 and then secondly when does it become biologically viable you have people that are coming into a landscape where they've never been no humans ever been there right they don't know when they're in alaska that north america is down there right there's no stores along the way they can't pack a lunch and make it from alaska down to the northern plains of north america in a day right it's going to be a long passage so they're going to have to wait until that passage has plants growing has animals in there eating the plants and we know that now because of ancient dna work that um i did with esky wilderslev's group at geogenetics we have evidence from lake cores of when animals and plants started to colonize this corridor region worked by another team led by beth shapiro in california showed bison populations in alaska and bison populations further south south of the ice their movements and their exchange uh through that corridor so we now know that my automatic lights just went off we now know that the uh corridor into the americas the interior corridor did not open early enough to meet the timing of the sites that we have in other words we have sites that are older than the opening the viable opening of that corridor so now everybody's attention is focused on the coast because the first people into the americas must have come that way again things that we wouldn't have been able to resolve a decade ago very very interesting um [Music] let's see uh let's talk a little bit about your book what section of the book are you particularly proud of and what do you find particularly interesting i know that you love them all yeah right like all your children right you don't pick a favorite um and you like them for different reasons so um well look these this is this is where i do my research and and i you know these are these are questions that i've been and been working on and thinking about for a very long time um and writing about for a very long time i should i should probably explain this book is based on um i published quite a number of papers on this topic papers in the scientific journals uh and so what this book is for me is an opportunity to take what i've learned that's gone through the gauntlet of peer review and and provide it in a in a way that um is it's good for a public audience because i mean fundamentally this is a really interesting question um and this is a really interesting time period and so um you know putting all this together has been uh just a lot of fun for me um if i had a favorite oh boy all of it um no you don't want all of it okay so look every every chapter is new in the sense that um i've gone through and i've learned in the process of doing this i've learned a lot um in a whole lot of different areas so for example chapter two is on the environment um and there's a there's a huge debate raging uh within the sort of glacial geological field about the causes and consequences of end of the pleistocene warming and specifically a very brief return to cool conditions it's called the younger driest and i've been involved in a lot of the research on you know we have this this cold snap that happens at the very end of the ice age what impact did it have on people um how would we know it was this happening at a rate fast enough to be even detected by people so it was fun for me to sort of get into that literature and try and figure it out myself um spoiler alert um we don't actually still know what caused this particular event but it was it's been really interesting to me to have to go off and read the oceanographic literature right so the fun thing for me is actually the process of trying to figure it out uh and then write about it in a way that's um intelligible um [Music] and and makes sense um so that part was i enjoyed redoing chapter two chapter three was is historical um and even though nobody came back from the dead there were new things to know about the 19th century controversy over the peopling of the americas um chapter five in the genetic stuff was probably a um the most challenging and the most fun in the sense that with the genetics literature it's happening so fast that you know you you read a paper and you think you've got everything understood and then two weeks later another paper comes out you think oh well here we go again i got to redo everything um so the genetics literature was fun because i was kind of racing to keep up with you know the very last minute uh latest findings on it and to explain it and that was a challenge but the other piece of this book is not only has it sort of gone through the gauntlet of peer review it's also gone through maybe an even tougher audience which is my students right this book um with you know certain changes in a lot of slides uh is an entire course that i teach and it's a tough audience right so you know yeah i can get through peer review that's not a problem this is what i do right i'm an archaeologist i can i can write papers i can get them published keeping undergraduates interested now that's a challenge uh and being able to explain it uh is a challenge so um anyway chapter five that was uh that was a tough one to write but the most fun i think to write just to make sure that i fully understood what was going on and i could be conversant now i need to say too that i'd go on a lot of search and seizure missions across interdisciplinary lines and thankfully i have colleagues and collaborators and friends who will keep me from making mistakes and i'm always always willing and sort of pushing to get them to tell me look am i misreading your evidence uh make sure that you keep me on the straight and narrow here um and that's been a lot of fun um especially in the last decade when i've been working very closely with geneticists because this is not a field i'm trained in um i can't do this i can't go into the lab and sequence a genome on the other hand my geneticist colleagues they can but they don't see and haven't got the background in terms of understanding the big picture and the questions that we're trying to answer so it's been really fruitful and a wonderful collaboration to sort of be able to bring this into the book and talk about all the things that we've learned by virtue of sort of bringing all our strengths together i don't know your core audience for this book your students and you said that they're one of your biggest challenges tell us a little bit about the challenges that you face or your students face when encountering this material yeah well i mean in the midst of a global pandemic a lot of it is just everybody's behind the mask so you can't tell if anybody's getting it or not that's that's a challenge no i mean look i feel an obligation to present our research to the larger community whether it's folks who are just interested in this question uh or our students and and what you have to do is present the science but i don't dumb it down i mean this is really important to me i want to make sure that what i'm writing is is reliable it's precise it's valid and it's well explained and sometimes it's tough sledding i absolutely get that right um but uh you you really make an effort to make sure that you're taking complex things and explaining them in a clear manner without simplifying too much i mean there are certain bits that you just have to say trust me on this one because if we go down that rabbit hole we're never going to come back right um so you know you make the effort to really make sure everybody's coming along with you and that they fully understand what it is that you're saying and and that's why you know in the classroom i'm constantly tracking everybody's facial expression i'm looking at their eyes i'm looking at their expression and i'm making sure they get it when you're not in the midst of a global pandemic and wearing masks and what did the students get most excited about you know it varies um i'm teaching an honors class this semester and um one of the things that i'm seeing a lot of is that they're really interested in the ethical issues which have have also become much more prominent in the last decade because we're talking about dna right and dna is a fundamentally very personal thing and there's a lot of discussion within the scientific community within the indigenous native american community about the use of dna now when you're doing genetic research with live folks you me whoever you have to have a consent form you have to get permission to do this research well who do you ask permission from uh when you've got us an ancient individual nine ten twelve thousand years old who speaks for them and how do you speak for them and what should you do um when you have that kind of situation and one of the nice things that's really emerged in just the last really just half dozen years is that there's been much better collaboration between the scientific community the archaeologists the geneticists and members of the indigenous communities so for example when we uh sequenced the kennewick genome kenoik was a a terribly controversial find it it literally led to 20 years of debate uh and a tug of war as to whether the ancient remains would be studied or whether they would be returned to a number of claimant tribes in the pacific northwest who felt that kenoik uh the ancient one they referred to him uh was an ancestor of theirs and should be brought back to them they didn't want the study done um there was a study uh and at the end of that study we uh obtained a small sample of kennewick's um uh finger actually and worked with um a number of the tribes some of whom in fact uh some individuals provided uh genetic samples that we could use for comparison by doing that um it really i think in a lot of ways um has helped change the conversation uh for the better between the scientific community and the native american community because there are really important things to learn about the past from uh dna and not just things that we're interested in as you know people who are interested in the people in the americas but also things that are of great potential interest to uh native american communities so it's it's gotten a whole lot more um nuanced this whole discussion uh you know before we sort of you know you would excavate a site you would find stone artifacts you'd report the age but now when we're dealing much more directly with people ancient people it's become a much more interesting conversation and hence a lot of the interest in the ethical implications of what it is that we're doing great well i've seen that there's a lot of questions that are starting to come in and even before this webinar i believe yesterday we got the first question and that is is there any archaeological evidence to show whether the first migrants over the bering land bridge and their descendants simply kept going until they reached tierra del fuego or if the americans were populated by a series of leapfrog movements with the newcomers passing through the already settled groups until they reached empty land where they could settle okay i need to unpack that in a couple so um first coming down the coast um one of the sort of virtues if you're if you're coming into a new world and you don't know anything about it you're you're in siberia you're in alaska it's all pretty much the same thing right you can go from northeast asia into alaska across the bering land bridge and mind you you know it's more than a thousand kilometers wide so you have no sense that you're you're going from one hemisphere to another and it all looks pretty much the same the adaptations don't need to change imagine coming down south of the ice sheet and you're in sort of the pacific northwest and you start to move interior as you go south it's going to look very very different you're going to see animals you've never seen before you're going to see a lot of plants you've never seen before um you're going to have to learn that landscape if you come down the coast and if you stay on the coast and this i think was the question that was being asked you can actually move fairly quickly because the structure of the environment is going to be relatively similar down the coast now it's it's obviously going to change when you go from the coast of southeast alaska down to say the santa barbara channel right because it's getting warmer you're getting further south resources are going to be different but the changes will be more incremental but if you go from say the pacific northwest out onto you go up the columbia river drop into the snake river drainage you get out onto the northern plains it's a whole different ball game right so you can move relatively quickly in in environments that are more homogeneous but when you're starting to cross ecological boundaries it's a lot more complicated and we think that um and this is getting to the leapfrog issue of question we suspect that people were moving into environments large sort of patches um they'd sort of figure out what was going on and they they'd exploit a variety of different patches within a habitat all the while probably sending out people one of the things that that a long-time colleague of mine lewis binford used to say regularly was insurance for hunter-gatherers is not knowing what you have right in front of you it's knowing where you go when things go badly where you are so we suspect that groups that are out on this completely unknown landscape they don't know what's going to feed them what's going to help them what's going to cure them what's going to try and kill them because there were some fairly formidable predators out there right they're going to be constantly looking over the next hill what's over the next hill what's over the next hill that would have been advantageous to them as as newcomers to a new land now the important thing is is that you don't want to go too far too fast because if you get going too far too fast and you sort of leave everybody else behind one day you're going to look around you realize oh we haven't seen anybody for weeks or months or years right no smoke on the horizon no freshly killed animals where's everybody else and you're going to realize at some point you know my kids are a marriageable age i've got to find some other people out here so we suspect these folks were highly mobile we suspect they were in fact sort of jumping all over the place and checking out their new landscape but we also suspect that they were making a strong effort to maintain distant connections so that they could exchange information so that they could exchange mates so they could tell one another okay this is what works out here we've left a cache of stone piled up under a tree if you go you know three weeks in that direction and follow this drainage up that way you'll see these kinds of things here waiting for you we left them there for you um so it must have been an amazing experience to come into this environment where no human had ever been before and and explore it and when they came in it was a wonderful place to be you know north america at the end of the ice age it's emerging uh the environments are changing probably not that fast that people would have noticed um but it was completely untouched it was a completely new landscape i don't know i hope that answered the question that was a great answer i'll see one of the questions that has come in on the q a can you tell us how your work fits with or challenges indigenous descendants own versions of their histories yeah so this is something that i've wrestled with um and this is also something that i'm not qualified to um speak to right uh i'm an archaeologist i recognize the limits of my ability um there are and i've had conversations with um folks who um have talked to me about oral history and the importance of oral history and the potential value of it i've stayed focused on the archaeological side of things because i don't want the archaeological record to be used against oral history or uh in favor of oral history because i don't think these are kind of the same mechanisms for measuring the past or for looking at the past and i don't really think that we can pull them together very effectively uh so my goal has really been to say okay here's what we know from this perspective um and and here's what the sort of the evidence that we have at the moment tells us uh and i also am willing to and interested in uh hearing about what the native perspectives might be as they may overlap or not uh with the evidence that i can uh that i can pull together okay next question did dogs or wolf dogs arrive with the first peoples or had domestication of dogs yet to take place um this is a very timely question because just a couple three months ago we published a paper on just that topic and this came about because colleagues of mine who work with dna in the ancient dna of dogs over at oxford university i was over there giving a talk a couple of years ago and i was looking at their dog dates right these are the this is what we know about the history of dog domestication this is um what we know about how dog populations started to split off from one another and i was looking at those dates and i was thinking you know those kind of match up with the dates that we have for people and people coming into the americas and then it it dawned on me i don't know why i hadn't thought about this before but the fact of the matter is is that people can come to the americas without dogs but dogs are not going to go to the americas without people and so when we pulled our data together what we realized was that human population movements and the splits that are taking place within the human populations okay so you've got your northeast asian groups then you've got the groups that are leaving and heading across the land bridge we've got a split of the people record right about there again 23 000 or so years ago well sure enough there's a split in dog populations about that same time right so you've got asian dogs and you've got dogs that are splitting off and heading into the americas and then once they get south of the ice sheet you've got these human populations that are diverging as they're moving south at different time points dogs are doing the same thing so clearly um we came the one we we came to the america with our best friends uh uh the uh the dogs came with us uh the dogs came with people and they were probably uh and dogs by the way are the very first domesticated species and they were domesticated literally 10 000 plus years earlier than any other domesticated uh species and they were probably an integral part of the cultural repertoire in other words dogs would have been extremely valuable to people they would let you know when predators were on the landscape and nearby they would help with the hunt they could help carry stuff in a pinch you could probably have them for dinner if you know if you didn't have enough food uh so dogs were probably an integral part of that of that movement into the americas and we just published that in the proceedings of the national academy of sciences a few months back and in fact there's a there's a bit of discussion of that in the book in first peoples i managed to squeeze it in um [Music] it literally is you know this is brand new stuff but uh it's in the book great okay what is your opinion of pre-columbian trans-oceanic contact theories um i'm not i'm not a fan um and i'll tell you why um we know when people started moving out across the pacific and and we know this and it's it's really quite clear because every time uh folks got to a remote island in the pacific you can tell and the reason you can tell is that in the archaeological record in the sediment record you see um deforestation you see a lot of the flightless birds that lived on these islands uh you know just think of the dodo right um you know humans got onto these islands and they very quickly you know realized oh there's birds walking around they can't fly because they've been living on these islands for literally thousands and thousands of years and they've become an endemic species you just walk up to them with a stick and whack them on the head the rats and the dogs that were in the outrigger canoes they're eating the eggs so there's a tremendous human impact on these small islands as people move across the pacific none of that predates 3000 years ago right and people get to the far far eastern pacific places like rapa nui hawaii uh only about a thousand plus or minus uh years ago so yes people did move across the pacific but that's not part of the story of the original initial peopling of the americas which again takes place 15 000 plus years ago did they subsequently once they got to places like rapa nui actually reached south america well there's been some papers that have literally just come out weeks ago just a few weeks ago that are in fact suggesting that some uh oceanic groups did in fact get to northern northwestern south america uh and then went back to places like i think tonga is one of the islands um because there's some suggestive genetic evidence of native american dna on some of these remote pacific islands so moving across the pacific in terms of reaching the americas early on not not really any evidence for that but uh contact between um groups coming out of oceania and native americans um that's an answer that still hasn't been resolved um but we're getting close on that one okay the next question um many thanks for the very interesting lecture has any evidence been found yet near the coast to prove people arrived in the americas by boat and what is the percentage of neanderthal dna in the samples of old dna right so um no watercraft have been found as yet the oldest evidence that we have along the coastal route a potential coastal route uh the earliest evidence we have a footprints is quite literally footprints there's a a remarkable sight on the british off the british columbia coast where preservation has yielded literally a set of human footprints on a mud flat and they've been radiocarbon dated to around 13 000 years ago so it's not the footprints of the first people coming down the coast but it's a certainly a very early set of footprints um watercraft you know that um the odds are slim um if they were making boats out of wood um there's probably not a whole lot of wood that would have been available except driftwood and that might have been a real challenge to make a boat uh out of out of driftwood um skin boats were possibly used but those are simply not going to preserve in the archaeological record or at least so far i mean the archaeological record can occasionally surprise you and preserve things that you never would have thought preserved so um if if there were boats used we may one day get lucky but so far we haven't as for the percentage of neanderthal dna um generally we're talking about two percent plus or minus um uh basically um about the same that i have in me okay so how reliable is this new ancient dna data and the analyses for example in the literature i have seen that the earliest dates for the appearance of homo sapiens sapiens are anywhere from 150 000 to 200 000 years bp somewhere even 300 000 bp presumably from mitochondrial dna so so-called mitochondrial eve so if it uh if it gives diversion dates how reliable is it yeah so um it's fair question so with um molecular the molecular clock so to speak um which is giving us those kinds of age estimates the molecular clock is as good as the calibration rate uh and the calibration sort of time point that you're using to determine uh things like mutation rate um and these kinds of ages depend on you know how how accurate is your mutation rate what's your generation time various other factors so they have big error bars no question about that um however uh as the years have gone by we've gotten a much better handle on mutation rates and can get more precise i'm not saying look this isn't radiocarbon dating right we're not getting something to plus or minus 50 years because we're talking about processes we're talking about rates that we have to estimate and or infer but what's happened in again in the last 10 years or so is that when you're looking at the dna of radiocarbon dated specimens you know precisely their age and so you can get a much better handle on how old they are and thereby get a much better handle on the mutation rate between them and moderns and between them and their shared ancestor so um absolutely you know the the early mitochondrial uh age estimates 160 to 200 000 um yeah you know that's a big ballpark uh that far back as you get closer however as you get closer to the present um the the error margin shrinks it's still there um you know this is when you when you work in deep time this is what you live with uh you know i'm a pl i'm an archaeologist plus or minus 100 years i'm good with that um it would not work if you know you're heading to the moon and you say you know plus or minus a million a million miles and i'll hit the moon that doesn't work uh so for us you know time it's a little slippery as you get further back now to the the question about modern humans we actually have skeletal evidence of early modern humans in africa that um depending on you know the interpretation uh could potentially be as old as 300 000 years uh so uh we are starting to see convergence between genetic records fossil records archaeological records i hope that answered the question okay next question was the coastal route on foot or by both or both or separate you know i think they were walking and i think they were walking partly because um well if you're walking you can still take advantage of uh near shore resources right you can you can get into tide pools you can collect things in tide pools but if these folks are coming across out of northeast asia uh i suspect the predominant subsistence strategy is to go after terrestrial resources to go after resources that live on land excuse me so my suspicion is is they were coming down the coast at a time when the ice had retreated and mind you you also had animals that were living along the coast that as the ice was advancing are getting sort of pushed onto offshore islands and the like so there probably were terrestrial resources um and we know this actually from some of the ancient caves that have been excavated along the coast um that there are land mammals there so it was probably the best of both worlds if you were walking down the coast if you if you're coming down the coast by boat and you fall out that's not a good thing right hypothermia sets in pretty quickly in that part of the world at the end of the ice age so um i suspect they're walking um i suspect they're taking advantage of near near shore resources as well as terrestrial resources they weren't doing deep sea fishing at this point in time that we're pretty sure how much work has been done in terms of pollen analysis in order to work out whether plants and which plants were growing in a given area in terms of when it was feasible to make uh to make the journey and establish a permanent or semi-permanent settlement yeah lots uh is the quick answer um i mean people have been doing uh polynomial i in a lot of my projects i'm working with palinologists um because that gives us a really detailed and rich record of the vegetation that was available on the landscape and importantly vegetation and also the climate at the time because by looking at the types of plants that were growing based on the pollen you can get a sense of because these plants and trees and what not have different sort of ecological and climatic tolerances by looking at the pollen record you can get a pretty good sense of what the environment and the climate were like so there's been a tremendous amount of that work done it varies geographically and it varies geographically because pollen gets preserved very well in places like uh ancient lakes where you can take a core out of a lake um and a project that we just wrapped up and have a book a separate book coming out this year on a site in the rockies we pulled a five meter long core out of the floor of this lake and we have a record of vegetation for the last 16 000 years which has helped us understand the environmental and climatic context within which the site that that we're writing about in this other forthcoming book um we have we have a really good sense of what the environmental context was of the people who were living in this region um 12 000 years ago so absolutely it's it's really important um and it does in fact help us get a much better sense of where people were why they were where they were when they were um is there any kind of pattern to migration or do people settlers migrate in a random way yeah so um chapter seven of the book actually has a lot of discussion about this um we don't the quick answer is we don't really know whether it's random or pattern simply because we don't have enough sites right we've got sites and we can connect those dots but that doesn't necessarily mean that they travel from dot a to dot b what we suspect and i talk about this a fair amount in chapter seven is the whole question of how what would be the most feasible way of moving across a landscape and i talk about landscapes that are easy to traverse but hard to navigate um so for example the great plains of north america you can just walk for days but it's you know if it's a cloudy day and it's just flat for thousands of miles around you it's kind of hard to figure out which direction you're going right um you can if you've got uh planes and mountains in the distance you can orient yourself so travel can be easy finding your way can be hard finding your way can be easy travel can be hard i suspect and again this is suspicion more than anything else that groups are kind of way finding by moving along major river systems they're moving along where they can kind of track um uh topographic high points to continue to orient themselves uh there's a huge literature out there about how people learn space and sort of how they learn how to navigate space and and i talk about some of that uh in chapter seven as well there's some really interesting psychological studies um about differences in spatial awareness and and how people sort of apply that to uh landscapes and the possibility that it might be in some sense gendered um that has to do with sort of our human evolutionary past in how uh you know if you had sort of dimorphism sexual dimorphism in terms of who's doing the hunting and who's doing the gathering that requires sort of different spatial knowledge and being able to find things again as opposed to just wandering off and going hunting and finding your way back so the answer is we don't know what the patterns were but there's uh it's a lot of fun to sort of think about it okay we have a comment from richard fisher who says very interesting and compelling discussion broadening the chronological focus a bit how can one reconcile the earlier dates of west coast migration kenwick at circa 16 000 bp and the much earlier remains and fines in lower south america earlier remains in fact scouts or advanced exploratory parties of the main migration or separate settlements and movements that happened considerably before 16 000 bp yeah for a long time it was challenging to have the oldest site in the americas is about as far from the bering strait and bearing land bridges you could get right we had monteverde in chile dated to around 14 700 or so and we had nothing to the north there's no way that people got across the bering land bridge and then simply leapfrogged all of north america and ended up in far southern south america so yeah um it was a challenge to reconcile but that's changing right we are and and there's a number of new old sites that have been discovered in north america those are in chapter four beatrice i'm trying to remember to plug the book so i will make a reference to the chapters um i get going um so we've got these sites now in north america that are as old um and in some cases older than monteverde so the pattern is starting to make more sense so the question is absolutely on point um you should see the oldest in the north and moving progressively down further south what we're seeing though and this is really interesting um in the genetic record that we have we're seeing evidence that that movement was really fast and and the evidence the nature of that evidence is that we have uh in genomic sequences from south eastern brazil individuals whose um whose ancient genomes are extremely similar to ones from north america which means that there weren't that many generations separating these two populations so boy it really looks like people got into the americas and they went just blasting out across the hemisphere and the other thing is that we're also seeing in the genetic record is that their populations were expanding dramatically there's something like the geneticists are currently estimating something like a 60-fold increase in numbers when people got to the americas and started dispersing uh throughout the hemisphere wow okay what do you think about the solution theory okay um so yeah i've been um i'm on record as being um skeptical of the solution theory and i'm skeptical for a whole variety of reasons um i've published with colleagues uh questions about the archaeological evidence on which it's based i've published with colleagues about uh the genetic evidence which shows that it didn't happen i mean fundamentally it it doesn't work and here's why it doesn't work if a group of solutions okay so just to make sure everybody's on the same page here salutrians are people who are in um northwest europe and france and spain uh 18 to 20 000 years ago and there are some similarities between uh certain there's a few similarities let me underline the word few between uh silutrian technology and artifacts and artifacts in technology in clovis but you need to understand too that there's about a six thousand year gap between solution and clovis right so there's a huge span of time in between those two things so yeah you've got similarity but you know does that mean there's a direct historical link doubtful and here's why if a group of solutions do in fact make it over from northwest europe and land in the americas they're going to come equipped with their full complement of culture so what you would expect in the early american archaeological record is a whole suite of archaeological materials that would be basically identical if not highly similar to what they had brought over and we don't see that we don't see that at all um early on it was supposed that with individuals like kennewick that maybe he didn't quite look like native american so maybe he possibly had come from someplace else we showed that kennewick is in fact native american absolutely but most importantly of all when esky's group [Music] when we sequenced the ansic genome which is the genome of a clovis child um young child buried with clovis artifacts he was absolutely native american and there was absolutely nothing solutrean or european about him right so if if in fact somehow solutions made it over here they had complete and total cultural amnesia they forgot all about the artifacts that they were making in northwestern europe they had genetic amnesia they left behind their genomes there's just absolutely no evidence for it so yeah that's in chapter six we have time for one last question and uh david kilby writes on behalf of my intro to archaeology class as genetics becomes a more powerful tool what does archaeology bring to the table what can archaeology tell us that genetics can't um hi dave that's not a plant but i do know david kilby uh so look archaeology still tells us hell of a lot uh there's no question about it genetics it's wonderful but it doesn't tell us about the nature of people's adaptations it doesn't tell us precisely when people arrive in the americas it doesn't tell us why people left northeast asia it doesn't tell us what challenges they face it doesn't tell us anything about the environment through which these groups pass so you know genetics is is great but it's not a replacement and you know we've we've sort of been living in kind of a golden age you know this technique and this technology was invented and suddenly you know everybody wants to do genetics it's really cool you learn a lot i get all that um but it's just one it's just one um one person at the table as it were i'll use i'll use dave kilby's metaphor everybody gets a seat at the table everybody still has to have a seat at the table because there's so many things that genetics can't tell us about the whys in the house and the wherefores and the whens that it's not going to replace us we've still got job security as archaeologists okay i think that just about wraps up where we are thank you so much for such an interesting fascinating wonderful webinar and thanks to all the participants also for tuning in and listening to this wonderful uh communication thanks so much

Channel: Cambridge University Press

Views: 3,960

Keywords: ice age, north america, archaeology, prehistory, american archaeology, native american

Id: nF7Z0xrjXSc

Length: 57min 38sec (3458 seconds)

Published: Tue May 04 2021