For those of you who don’t know, all students in UNCG’s 300+ level anthropology courses are reading a book and several articles in preparation for the Harriet-Elliott events. One of these readings, John Relethford’s “Reflections of Our Past,” has a chapter on the peopling of the Americas. Traditionally, most scholars contend that the first humans entered the Americas about 15,000 years ago (or maybe a bit earlier) and came from Asia via the Bering Land Bridge that then existed between modern-day Alaska and eastern Siberia.
Possible migration routes for the first colonization of the Americas
According to Relethford, who was writing in 2003, the genetics strongly supports an origin of Native Americans somewhere in Asia:
1. Contemporary Native Americans and northern Asians tend to have high frequencies of the Diego blood group allele DI*A (this allele is relatively rare among other populations).
2. Based on genetic distance analysis (which takes into account the relative frequency of many different genes simultaneously to look at overall genetic difference/similarity), contemporary northeast Asian populations are most genetically similar to Native Americans.
3. Native Americans share a number of mitochondrial DNA haplotypes (sections of DNA that are inherited together as a single unit) with Asian populations (some from Siberia, some from Japan and Korea).
Relethford also discusses another interesting question: how many migrations occurred? Was it a single migration event? Two? Three? More? The genetic data seem to suggest at least two separate migration events, if not more.
Finally, when did the first colonization of the Americas take place? Here, Relethford shows that the genetic data are pretty cloudy because any estimate based on a genetic clock will be affected by population size and the overprinting of multiple migrations. Indeed, Relethford suspects that “the final determination of the age of the first Americans will be settled by archaeology and not by genetics.”
The 2011 Harriet-Elliott Lecture Series blog 
I read the Relethford book over the winter break. I thought it could do with some updating. He did not mention that there has been a mitochondrial DNA study of Native Americans that indicates how many women came in the first group (Achilli et al. 2008) and a lot else. It was informative in a lot of other ways about genomics that I needed to know about.
One of the really important things that is going on now is the possibility of Paleoindians coming out of the European Solutrean. The lithic analysis for this study done by Larry Bradley and Denis Stanford (2004) is very convincing. (I have an MA in French Solutrean lithics.) The genomic equivalent of the Soluteanoid lithics is the X haplogroup that Relethford does talk about. He seems to be indicating that it must have come across Asia from western Eurasia. This is not impossible. One of the surprises in Greenberg’s linguistic studies is that Eskimo Aleut is related to the Indo-European language group. However, the Inuit (Eskimos) were late arrivals. There are all sorts of circulations that go on in Asia, so it is a possibility.
However, the possibility that the X haplotype in North America, mostly in eastern North America, came via the ice from Europe deserves attention. Something that has come out since Relethford wrote his book is that there was a meteor strike in eastern North America around 12,900 BP that probably took the core of the Paleoindian population with it along with the elephants, rhinos, horses, certain species of oysters, etc., etc. (Firestone et al. 2007). Al Goodyear in South Carolina has been studying a point type called Redstone that appears to be a descendant form of the Paleoindian Clovis point. There are very few of them compared to the ubiquitous and numerous Paleoindian Clovis points. This can be interpreted in a number of ways but suggest that after the meteor there were a few stunned Paleoindians left. Their genetic population would have been swamped by people coming in from the west and south where the impact was not so destructive or direct. So it follows that there would be only a few X haplotypes left in eastern North America. Most of the current population would ultimately have derived from Asia, or even more probably from South America, and only a little from Europe.
That said, I still have to say that Relethford’s book was informative and well worth reading.
Achilli, A., U. A. Perego, C. M. Bravi, M. D. Coble, Q.-P. Kong, S. R. Woodward, A. Salas, A. Torroni, and H.-J. Bandelt. 2008. The Phylogeny of the Four Pan-American MtDNA Haplogroups: Implications for Evolutionary and Disease Studies. PLoS ONE 3:1-8.
Bradley, B., and D. Stanford. 2004. The North Atlantic ice-edge corridor: a Possible Palaeolithic Route to the New World. World Archaeology 36:459 – 478.
Firestone, R. B., A. Westc, J. P. Kennett, L. Beckere, T. E. Bunchf, Z. S. Revayg, P. H. Schultzh, T. Belgyag, J. M. Erlandson, O. J. Dickensonj, A. C. Goodyeark, R. S. Harrish, G. A. Howardl, J. B. Kloostermanm, P. Lechlern, P. A. Mayewskio, J. Montgomeryj, R. Poredap, T. Darrahp, S. S. Que Heeq, A. R. Smitha, A. Stichr, W. Toppings, J. H. Wittkef, and W. S. Wolbachr. 2007. Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling. PNAS Early Edition 104:16016-16021.
I should have mentioned that perhaps waves of Asian imigrants were in the Americas as many as 10 or 20 thousand years before the brief Paleoindian 13000-years-ago incursion occurred. Current thinking is that the Paleoindian Clovis period only lasted a few 100 years before being struck by the meteor.
Chapters 1-6: I found it very interesting that some sections of this book go so into depth about DNA sequencing and the chemicals involved. I know the book is about how history is revealed in our genes so it makes a lot of sense to discuss genetics, but I feel almost as if I should be simultaneously re-taking high school biology. Parts of this book are tending towards the overly technical, especially for a person like myself who is just trying to take a cultural anthropology course. I realize that anthropology has many branches and incorporates multiple sciences, and there is beauty in that overlap, but the fact remains that these very technical terms made it hard for me to read straight on through; I think in the the process, I may have been put off so much as to have missed the entire point of the chapter. That is my overarching complaint thus far. I guess I would really appreciate some broader summations and fewer charts. Or perhaps I simply lack a scientific mind, and therein lies my problem.
Like Dr. Gunn, I too found that this book was very outdated and could be revised as to have some more of the current findings within the text.
One of most interesting chapters for me was the chapter about the Neanderthals. This chapter, I feel, did a very good job explaining what could have possibly happened to this group. The analogy about the red and white paint, with no pun intended, painted the best picture of what might possibly have occurred to the Neanderthal population to me. The overwhelming of the more prevalent genes of the early humans over the genes of the Neanderthals could explain what may have occurred, assuming that Neanderthals and early humans could actually interbreed. The analogy shows that very little of the Neanderthal DNA would show up in modern humans because it has been overwhelmed by the DNA of what would evolve into modern humans.
The second most interesting chapter to me was chapter six. The discussion of how Native Americans could have gotten into the Americas was very interesting. Also, proving that they were linked to groups over in Asia genetically was fascinating to me since I had never read that study before. Also like Dr. Gunn said, the presence of gene X was very intriguing to me. How this distinctly European gene could end up in the Americas long before the believed first encounter just makes you wonder how this could have happened. Although in this chapter Relethford for the most part ignored the theory that I believe in about how Native groups moved into the Americas, by the use of boats along the coast. This could help explain how sites down in Chile are some of the oldest and how there are no older settlements that have been found along the upper parts of the West coast.
I found Relethford’s book a great read, and it was interesting because he had me thinking about my own ancestry and geneaology in relation to our human ancestor. He took a deeper look at our genetic comparisons to Apes and Humans and whether we should classify primates on the basis for evolutionary relationships or adaptations today. It was interesting to look at the facts when he began exploring the DNA sequences of primates, and looking at the genetic code to find out how closely related two species are. I found it a little confusing, but nonetheless pivotal to find out just how close we are to finding where the real origin of our ancestor lies. I liked the talk about how primitive traits don’t tell us a lot about evolutionary relationships because they are shared by all descendant species. People should definitely focus more on derived traits. The pattern of human genetic diversity as well as taking into account population size, genetic drift, and evolution defnitely painted a picture that our genetic diversity is a mixture of past events. It was great to see the support for Asian origin with the first Americans. There are plenty of physical similarities that suggest a historical connection between East and Northeast Asia and the Americas in Native Americans and East Asians. There were also genetic markers that show similarities between these populations because of something called the Diego blood group. Higher frequencies of DI*A are found in the East and Northeast Asian populations and Native American populations, which shows a historical link. The ability to find genetic connections in this book is widely available, and it was great to fill in the gaps.
I’ve really enjoyed reading Relethford’s book, he explains genetic topics through colorful metaphors that really helped me to better comprehend a lot of what am learning about. In Chapter one he introduces us to his passion and projects as he describes his search for his ancestry. He details what we are all familiar with, a dimming in knowledge of our own family the further away from us we look. Relethford presents his outline for “Reflections of our Past” and glosses over how genetics can help us uncover the secrets of not only the near but also the ancient past. In chapter two he discusses classification and describes how the purpose of a classification can change the categories we create but he doesn’t mention how we as a people are natural innate categorizers constantly sorting the multitude of information bombarding us. The chapter also discusses molecular dating and the narrowing time ranges for the split between modern humans and the great apes from our common ancestor. I like that Relethford acknowledges the conflicting views held by his colleagues Morris and Diamond.
Chapter three of “Reflections of our Past” is an interesting summary of human evolution, and Relethford confronts the question of species and how we should differentiate. It is difficult to define fossils as separate species because observing behavior is not possible and therefore we do not know which fossil would have been capable of producing viable offspring together. He discusses the “Mitochondrial Eve” project in which Mitochondrial DNA from people around the world was studied in order to discover their most resent common female ancestor. The researchers concluded that the earliest shared ancestor of all of us lived 200,000 years ago in Africa. Chapter four questions the “fate” of the Neandertals. Through DNA analysis and comparisons researchers know that Neandertals are a sort of distant cousin to the modern human line and that they are more similar to each other than to us. Relethford points out that there is still a possibility of the Neandertals being a subspecies of Homo Sapiens. He poses the hypothesis that through the extraordinary migration ability of humans that Neandertal was never fully cut off from contact with Africa and as modern humans emerged they could have still reproduced with one another. It is possible that Neandertal was “Genetically swamped” by Modern Human DNA because there were so many more of us.
Chapter five discusses the different methods of measuring genetic diversity, from blood types to DNA sequences. To calculate genetic distance between populations’ scientists look at the frequency of certain alleles in the comparison populations, if the two populations have a similar number of those alleles then they are more closely related than if not. The ‘Isolation by distance’ model predicts that genetic differences will increase with geographic distances until it reaches a plateau. When looking at genetic diversity between a population and an individual it has been shown that more diversity exists within a population. Chapter six is interesting and very relevant to this class, Relethford discusses the migration of the early Native Americans from Asia and how they could have gotten here. He neglects to mention a fascinating theory that suggests they could have come across on large floating rafts of vegetation that were blown about by storms. It is also possible that the New World Monkeys came to South America in this way shortly before their genetic line split from the Old World Monkeys.
The part that I found most interesting of the final four chapters was the part about Thomas Jefferson potentially fathering a child of one of his slaves. I have heard this story before in the past, but had never heard any conclusive evidence to support it. This chapter did a good job at summarizing that it could have possibly been Thomas Jefferson himself, but then there is also the possibility that another man from the Jefferson family could have also been responsible for the child.
Another part that I found interesting was in the final chapter. The discussion of Judaism and how similar they are to each other and how little they have interacted with outside groups is amazing to me. The even more intesting part to me was about the Kohanim group in Africa who claimed to have had a common ancestor in Moses’ brother Aaron. Through the testing of the Y-chromosome, they found that they did indeed, for the majority at least, have a common ancestor that was based about 106 generations ago and would have been between the Exodus from Egypt and the destruction of the first Temple. The fact that they can pinpoint an exact moment in time like that trough genetics is truly amazing to me.
Funny that the saying goes, it’s up to the man to carry on the name…but it appears to be up to the female to carry on the lineage! The discovery in 1987 of the use of analyzing mitchondrial DNA had great impact of studying the human past. This also made it possible to determine time periods between ancestors. That mitochondrial DNA can only be passed on to offspring by women is of incredible import when studying ancestry and has had impressive effects on anthropology. I found it very interesting that powered with this information, researchers have been able to link Asians and Native Americans genetically. I never really thought about the similarities in the physical characteristics of the two, but after having read these chapters it makes sense! I found the struggle over the Kennewick Man sad. What insight his remains would be able to provide is certainly intriquing, but at what ethical price?
From what I have read so far the book seemes rather interesting. I have never really looked into the genetics of humans. I really only know what I have been taught in other classes. It is very interesting how some of the traits in some Native Americans are similar to that of people in Northern Asia. It gives evidence that maybe the Native Americans really did come to America across the Bering Land Bridge. At one point in the book when the scientisits discoverent the remains in Washington State and identifie thenm as European was interesting as well. At first it seemed to give evidence that maybe there was some European and Native American contact before Columbus, but after further research it was proven that the remains were that f Native American descent. So far I have been really interested in what the author has to say, I can’t what to finish it and see what else he has to say.
As everyone has stated about how easy this book is to read and truly understand, I agree whole heartedly with them. I thought this was going to be a typical anthropology type book to read but from the very beginning I was captivated. When Relethford talked about his experience of his journey to his ancestry reminded me of the same journey that I explored a few years ago. Relethford really hit home with me when he talked about the movie Roots that was aired in January 1977 and that is what initially motivated him to go on his search. Upon reading this book I never realized how many people were involved in past generations. In the graphs on page 6 gave me a true understanding of how many grandparents, great-grandparents, great-great grandparents and so on that could be traced. But as he states how many of us can go back that far. Some may not even know their grandparents. I am fortunate to have known my grandparents on both sides very well. My paternal grandfather is still living at the young age of 90. I like how Relethford stated that when he is in a store he cant help but to think that the person that he is standing next to could be related to him in some form. That made me think about when I was in high school and my grandmother would always ask about the person I am dating parents and grandparents. She would say that “it’s a small world out here and you never know who you may be kin to”. Another point that stuck with me in the book is that according to Relethford he states that the oldest specimen first appeared in Africa was about 130,000 years old. Does that mean all our ancestors come from Africa? Others appeared in Europe about 40,000 to 30,000 years go. Hmmm…what does that tell you?
I have read quite a few physical anthropology books as well as many other anthropology textbooks and none of them compare to Relethford’s. I love how he comes at the topic of human evolution from a very personal perspective. He adds his own opinions and really makes the reading quite fascinating. I felt like I was reading a normal book and forgot that I was actually reading educational material. One of my favorite things was how he got around to describing ways to answer the question of “What are humans?” My favorite quote was “One the one hand, we all realize that humans are animals in a zoological sense, yet we frequently tell our children not to act like animals”. I don’t know why but I love this quote. The way Relethford went through the concept of genetically comparing humans and apes through DNA was really cool. He made every scientific topic in these chapters seem interesting and easy. Two things not normally associated with your average text for a class. I wish more professors assigned more readings like this one. I also found it interesting that gorillas only differ from humans in one amino acid. That’s pretty incredible when you think about it. I found this to be an overall fascinating and great read. I expect I will probably finish the rest of this book tonight.
I have found this book to be very enlightening in that expanded my knowledge of genetics beyond the eye color example given in biology class. I specifically found Chapter Three to be interesting because it explains the two main theories of how modern humans spread across the Old World. It was interesting to see how one piece of evidence, like “mitochondrial Eve” could have different conclusions for different theories. This common ancestor supports the African replacement theory because she lived before modern humans left Africa but it could also mean that the mtDNA was carried out of Africa through gene flow for the multiregional theory.
In Chapter Five, I was interested to learn how diversity among human populations could be tested. There are so many possibilities. Mostly these differences and similarities can be explained by geographic distances of the populations, but still gene flow from more distant populations occurs.
This book is very user friendly. I think it can be appreciated by someone browsing b&n or by a professor. Relethford does a great job breaking down processes, providing examples, and easy to understand metaphors, although he can be more long winded than necessary at times. I think as he begins with simple concepts and then delves step by step into the details it seems extra lengthy, but being thorough definitely has its merits. It has been a big brush up on those basic biology and anthropology principles for me. Chapter three gave some great insight into the “out of Africa” theory you hear so much about in entry level classes. All the different ways to follow lineage- through mitochondrial dna, and despite mutations, etc. was fascinating, even if he did deem it the less than monumental “mostly out of Africa” theory. The discussion of haplogroup X was frustrating to me. First it wasn’t in Siberia… then it was… but it’s hard to draw a conclusion from. Multiple migrations seems to be a reasonable concept at any rate. I look forward to reading the rest of the book
Relethford in the search of human origins has been an interesting source of new information. Since I have not taken physical anthropology most of this information is new and presented in a innovate way to me. When I took biology my professor was the genetics teacher and he made it a point in all his classes that he was not trying to talk over our heads with genetic jargon. This has resulted in complete distaste in what genetics has to offer. However, so far the book not been the most interesting material I have ever read, or even something that I would pick up on my own but it is not the disappointment that I imagined. The author Relethford has many interesting smilies, metaphors and stories that keeps the information comprehensible.
The most interesting chapter in my opinion is chapter 7. The worst would be chapter 2. The most relevant chapter to my education right now is Chapter 6, which is on the potential migrations that have happened in the Americas, was fascinating. Considering all the theories that he presents on how the Americans were populated really shows how open the world really is. I never heard of the Kinnewick man until this chapter, but his remains reflect all kinds or possibilities that could have occurred in the old world. The fossil record is probably what remains in truly solving what happened in those days.
I agree too that the Relethford book is an easy read. I really enjoyed how he basically told you in the first chapter what each chapter was going to deal with. I recently took a Biology class and we had to another book about how are genetics shape who we are. It was called “Mean Genes”. Anyway, I am fascinated by genetics and it was interesting to read Relethford’s explanations. I enjoyed the chapter on the comparisons between humans and apes. When he asked about knowing our family roots, I thought my family had traced ours back pretty well. Now I know we have only scraped the surface. Very interesting read.
We were taught so many erroneous things,out of the ignorance surrounding the subjects. The chapter discussing the mitochondrial DNA was fascinating, especially to see that there was an average of 27 differences between the Neandertals and other human species. This is amazing, when the average number of differences between living humans is only 8. I also enjoyed when Relethford was talking about the chance of there being a “mitochondrial Eve” or mother of all species and how scientists where looking for a common ancestor.
I actually took Bio 392 and Bio 393, “genetics lecture and Lab” and I really see how it can be incorporated into physical anthropology. The first several chapters show DNA works in the human ancestors between other species and Neanderthal. Also I understand why he considers of complaining or up roaring of using the traditional system of naming species in Chapter 2. My opinion is that we should use the traditional system of naming species, because hominid means what it means “great apes and humans,” and scientist that do taxonomy take this seriously. Good thing is taking in the genetic drift, population size, and human evolution or I say slight mutations within the human population for as a major influence on genetic diversity. The most interesting is the statistics behind the mechanisms of genetic drift.
I have to agree with the comments so far, in that this is an easy to read text. As a student who is relatively new to the study of anthropology, I have found that so far it has brought together many of the courses I am taking, emphasising the major themes I am looking at within lectures and giving me further insight. As a student from Ireland, I have to confess that I found chapter nine very interesting. Relethford combines his easy to read narrative with the right amount of scientific method and knowledge to keep readers interested. While it may be argued that some of his work is in need of being updated, overall I found the book an interesting and inspiring read.
Alright, reading the thread above, I have seen the mosiac of opinions concerning Relethford’s book. I thought I would insert that this book ultimately is aimed at an audience that is unfamiliar with the studies concerning human evolution and the concepts behind genetic research and what can be discerned from this research as far as relation and migrations. Thus I think this text serves as a great book for the mass public, but maybe not for 300+ ATY students. There is a great deal of review, but I am sure all of us could use it. If anything the analogies Relethford makes are quite vivid and cement the information perhaps learned in past classes. I think this text is a great teaching tool in that respect.
Food for thought.