Our most common male ancestor walked the earth 209,000 years ago -- earlier than scientists commonly thought -- according to new research from the University of University of Sheffield, says the January 22, 2014 news release, "Putting 'Adam' in his rightful place in evolutionary history." The pioneering study, conducted by Dr Eran Elhaik from the University of Sheffield and Dr Dan Graur from the University of Houston, also debunked the discovery of the Y chromosome that supposedly predated humanity.
Also previous research from last year (February 2013) regarding the Y chromosome in another study from other researchers, can be found in a study's abstract, "An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree," at the American Journal of Human Genetics site.
In the new January 22, 2014 research, published in the European Journal of Human Genetics, Dr Elhaik and Dr Graur used conventional biological models to date our most common male ancestor 'Adam' in his rightful place in evolutionary history. The ground breaking results showed that this is 9,000 years earlier than scientists originally believed, making the human Y chromosome about 209.000 years old.
Their findings put 'Adam' within the time frame of his other half 'Eve', the genetic maternal ancestor of mankind. This contradicts a recent study1 which had claimed the human Y chromosome originated in a different species through interbreeding which dates 'Adam' to be twice as old
Debunking unscientific theories is not new to Dr Elhaik. Earlier this year he debunked Hammer's previous work on the unity of the Jewish genome and together with Dr Graur they refuted the proclamations made by the ENCODE project on junk DNA. "We can say with some certainty that modern humans emerged in Africa a little over 200,000 years ago," says Dr Elhaik in the January 22, 2014 news release, Putting 'Adam' in his rightful place in evolutionary history. "It's obvious that modern humans did not interbreed with hominins living over 500,000 years ago. It is also clear that there was no single 'Adam' and 'Eve' but rather groups of 'Adams and 'Eves' living side by side and wandering together in our world."
Dr Elhaik adds, according to the news release, "We have shown that the University of Arizona study lacks any scientific merit. In fact, their hypothesis creates a sort of 'space-time paradox 'whereby the most ancient individual belonging to Homo sapiens species has not yet been born. If we take the numerical results from previous studies seriously we can conclude that the past may be altered by the mother of 'Adam' deciding not to conceive him in the future, thus, bringing a retroactive end to our species. Think of the movie Back to the Future, when Marty was worried that his parents would not meet and as a result he wouldn't be born - it's the same idea. The question to what extend did our humans forbearers interbreed with their closest relatives is one of the hottest questions in anthropology that remains open."
Almost a year ago, on February 28, 2013, the media reported on the discovery of a human Y chromosome that supposedly predated humanity in another study from different research teams. While previous studies put the age of the most common male ancestor, commonly referred to as 'Adam,' at approximately 200,000 years ago, a study published in 2013 by University of Arizona professor Michael Hammer and colleagues claimed that the age of 'Adam' is twice as old. To understand the meaning of this claim, imagine Earth half a million years ago.
Dinosaurs have been missing for a while, however, ancient hominins like Homo erectus and Homo habilis could still be found. Homo sapiens, on the other hand, has not evolved yet. The meaning of the University of Arizona study is that the human Y chromosome originated in a different species through interbreeding, contrary to all other molecular and paleontological evidence.
You can check out the abstract of the new paper online, "The ‘extremely ancient’ chromosome that isn’t: a forensic bioinformatic investigation of Albert Perry’s X-degenerate portion of the Y chromosome," published today, January 22, 2014, in the European Journal of Human Genetics. There's also a publicly available YouTube video recently posted, "Newly found Y-Chromosomal Adam - not so ancient as you may think," that explains the new paper.
The new paper published today in the European Journal of Human Genetics explains that these assertions were surprising for both Dr. Dan Graur of University of Houston and Dr. Eran Elhaik of Johns Hopkins University. Given that the two have a history of debunking aggrandized proclamations such as those made by the ENCODE project on junk DNA and Hammer’s previous work on the unity of the Jewish genome, Graur and Elhaik were hesitant to pursue another “debunking” project. But, they did.
Their findings were even more troubling than expected
“We have shown,” explains Elhaik, according to the January 22, 2014 news release, The study that (almost) wiped out the human race, “that the University of Arizona study lacks any scientific merit. Their hypothesis creates a sort of ‘space-time paradox’ whereby the most ancient individual belonging to the Homo sapiens species has not been born yet. If we take the numerical results from Hammer’s group seriously, we can conclude that the past may be altered by the mother of the purported father of humanity deciding not to conceive the child in the future, thus, bringing a retroactive end to our species.”
The video explains that on March 7 2013, Mendez and colleagues from Michael Hammer's group reported a most amazing discovery: an ancient Y chromosome that lies at the basal position of the Y chromosome phylogenetic tree and estimated to have emerged 338,000 years ago. The results had tremendous implications to the origin of our species and raised speculations as to the origin of the "Y chromosomal Adam."
Not surprisingly, the study had no biological nor mathematical support and the findings were achieved through data manipulation as researchers show in this video and in the latest paper, "The ‘extremely ancient’ chromosome that isn’t: a forensic bioinformatic investigation of Albert Perry’s X-degenerate portion of the Y chromosome," published online January 22, 2014 in the European Journal of Human Genetics.
In their new study, published in the European Journal of Human Genetics, Elhaik and colleagues used conventional biological models to place “Adam” in its rightful place in evolutionary history, some 209,000 years ago
Slightly older than what scientists thought so far, but within the time frame of his other half is “Eve,” the genetic maternal ancestor of mankind. The timing is also within the acceptable time frame for anatomically modern humans according to the fossil record. These findings strongly conflict with the conclusion by Hammer and colleagues that female Homo sapiens engaged in interspecific sex with males from other species.
The researchers share the excitement that increased participation by people of all ethnicities in population genetic studies will yield additional discoveries of who we are and where we came from, the paper explains
The scientists have, however, shown that when assessing new data, care must be taken in both data analysis and methodology to ensure that the results are scientifically robust. Regarding the funding for the latest research, NIH-NICHD: HD070996 and NIH-NIGMS GM068968 grants supported the work.
If you'd like to read more about last year's (March 2013) various studies of how 'old' is the earliest man and related topics, you may wish to check out studies and the news of such research such as the following news articles, "Human Y chromosome much older than previously thought, The father of all men," UA News (The University of Arizona), "The father of all men is 340,000 years old," New Scientist, "Human Y Chromosome Much Older Than Previously Thought," Science Daily, "African-American's Y chromosome sparks shift in evolutionary timetable," NBC News, "The family tree that rewrote human history: Researchers stunned to find DNA submitted to online project dates back 338,000 years," Mail Online: Science and Tech, "Earliest African American Man Dated," Discovery News and "'Adam' born 338,000 years ago in revised estimate," Genetic Literacy Project.
What did some of those former studies reveal in last year's news that said humans are much older than scientists formerly thought?
In late February and early March of 2013, news stories filled the mainstream media publications revealing then that the male Y chromosome in Homosapien humans is not 100,000 years as previously reported. The latest paper says the Y chromosome of human males is a little more than 208,000 years old, rather than that it's older than 338,000 years, just as old as Neanderthals. As you can see the research in the news of March 2013 is different than the work published in January 2014, regarding the age of the human Y chromosome found in males and passed from father to son.
Last year the news stories told of the discovery and University of Arizona (UA) analysis of an extremely rare African American Y chromosome push back the time of the most recent common ancestor for the Y chromosome lineage tree to 338,000 years ago.
This time predates the age of the oldest known anatomically modern human fossils, according to last year's research. In March of 2013, media news stories told of a newly discovered Y chromosome places the most recent common ancestor for the Y chromosome lineage more 100,000 years before the oldest known anatomically modern human fossils. It all depends on the age of a generation. Is a generation closer to 20 or 25 years or closer to 40 years? You can find out that answer in the January 22, 2014 YouTube video on the new paper. Check out the video for the date, so far, for the origin of the human male Y chromosome, "Newly found Y-Chromosomal Adam - not so ancient as you may think."
Now you can compare the January 22, 2014 video with another study by different researchers from last year's news on how old the male Y chromosome might be as you refer to the article, "An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree." Last year's study results by other researchers are published in the February 28, 2013 issue of the American Journal of Human Genetics. In that older study of 2013, University of Arizona geneticists searched for the oldest known genetic branch of the human Y chromosome. After all, if you have a human Y chromosome, you're a human male. Women don't carry the Y chromosome. It's inherited only from father to son down through the ages.
Scientists discovered the oldest known genetic branch of the human Y chromosome
University of Arizona (UA) geneticists have discovered the oldest known genetic branch of the human Y chromosome – the hereditary factor determining male sex. The new divergent lineage, which was found in an individual who submitted his DNA to Family Tree DNA, a company specializing in DNA analysis to trace family roots, branched from the Y chromosome tree before the first appearance of anatomically modern humans in the fossil record.
This shows that humans were around more than a quarter of a million years ago, not that the man carries the Y chromosome (his earliest founding father) of another type of hominid. It's a modern human Y chromosome, found in people today and had previously existed 338,000 years ago when father passed that same Y chromosome on from one son to the next across generations until the present day.
"Our analysis indicates this lineage diverged from previously known Y chromosomes about 300,000 ago, a time when anatomically modern humans had not yet evolved," says Michael Hammer, in the March 4, 2013 news release, Human Y chromosome much older than previously thought. Dr. Hammer is an associate professor in the University of Arizona's department of ecology and evolutionary biology and a research scientist at the UA's Arizona Research Labs. "This pushes back the time the last common Y chromosome ancestor lived by almost 70 percent."
Looking for the earliest common Y chromosome human ancestor
Unlike the other human chromosomes, the majority of the Y chromosome does not exchange genetic material with other chromosomes, which makes it simpler to trace ancestral relationships among contemporary lineages. If two Y chromosomes carry the same mutation, it is because they share a common paternal ancestor at some point in the past. The more mutations that differ between two Y chromosomes the farther back in time the common ancestor lived. Humans were around hundreds of thousands of years earlier than most scientists ever thought.
Originally, a DNA sample obtained from an African American living in South Carolina was submitted to the National Geographic Genographic Project. When none of the genetic markers used to assign lineages to known Y chromosome groupings were found, the DNA sample was sent to Family Tree DNA for sequencing. Fernando Mendez, a postdoctoral researcher in Hammer's lab, led the effort to analyze the DNA sequence, which included more than 240,000 base pairs of the Y chromosome.
Hammer says in the news release, Human Y chromosome much older than previously thought, "The most striking feature of this research is that a consumer genetic testing company identified a lineage that didn't fit anywhere on the existing Y chromosome tree, even though the tree had been constructed based on perhaps a half-million individuals or more. Nobody expected to find anything like this."
How the prehistoric hominids differed from people around today
About 300,000 years ago falls around the time the Neanderthals are believed to have split from the ancestral human lineage. It was not until more than 100,000 years later that anatomically modern humans appear in the fossil record. They differ from the more archaic forms by a more lightly built skeleton, a smaller face tucked under a high forehead, the absence of a cranial ridge and smaller chins.
Hammer said the newly discovered Y chromosome variation is extremely rare. Through large database searches, his team eventually was able to find a similar chromosome in the Mbo, a population living in a tiny area of western Cameroon in sub-Saharan Africa.
Similar chromosomes exist in a tiny area of western Cameroon
"This was surprising because previously the most diverged branches of the Y chromosome were found in traditional hunter-gatherer populations such as Pygmies and the click-speaking KhoeSan, who are considered to be the most diverged human populations living today," Hammer says in the news release.
"Instead, the sample matched the Y chromosome DNA of 11 men, who all came from a very small region of western Cameroon," Hammer explains in the press release. "And the sequences of those individuals are variable, so it's not like they all descended from the same grandfather."
Hammer cautions against popular concepts of "mitochondrial Eve" or "Y chromosome Adam" that suggest all of humankind descended from exactly one pair of humans that lived at a certain point in human evolution. "There has been too much emphasis on this in the past," he said. "It is a misconception that the genealogy of a single genetic region reflects population divergence. Instead, our results suggest that there are pockets of genetically isolated communities that together preserve a great deal of human diversity."
Genetically isolated communities preserve more human diversity
Still, Hammer said, "It is likely that other divergent lineages will be found, whether in Africa or among African-Americans in the U.S. and that some of these may further increase the age of the Y chromosome tree." He adds, according to the news release, "There has been a lot of hype with people trying to trace their Y chromosome to different tribes, but this individual from South Carolina can say he did it."
The study came about by combined efforts of a private business, Family Tree DNA, the efforts of a citizen scientist, Bonnie Schrack, and the research capabilities at the University of Arizona. Mike Hammer, PhD is Family Tree DNA's Chief Scientist, and member of the Scientific Advisory Board.
A Biotechnology Research Scientist at the University of Arizona with appointments in the Department of Anthropology and the Department of Ecology and Evolutionary Biology, as well as Director of the Genomic Analysis and Technology Core facility, Dr. Hammer received his PhD in Genetics from the University of California at Berkeley and was a post-doctoral fellow at Princeton and Harvard Universities.
Using advanced analysis of DNA from Y chromosomes from men all over the world, scientists have shed new light on the mystery of when and how a few early human ancestors started to give rise to the incredible diversity of today's population.
The recent study is often referred to at the Y as in the latest research on Y chromosomes that have now been fully sequenced. The Y: Research on Y chromosomes finds new clues about human ancestry. First full-chromosome sequencing effort shows most recent male and female common ancestors lived around the same time. More than 7 billion people live on this planet – members of a single species that originated in one place and migrated all over the Earth over tens of thousands of years. But even though we all trace our family lineage to a few common ancestors, scientists still don't know exactly when and how those few ancestors started to give rise to the incredible diversity of today's population.
A brand-new finding, made using advanced analysis of DNA from all over the world, sheds new light on this mystery. By studying the DNA sequence of Y chromosomes of men from many different populations, scientists have determined that their male most recent common ancestor (MRCA) lived sometime between 120,000 and 156,000 years ago.
It's the first time the human ancestry has been traced back through the male line by sequencing the DNA of many entire Y chromosomes
And, it agrees reasonably well with previous findings about our female most recent common ancestor, made by studying DNA carried down through the human race's female line. Such studies used DNA from mitochrondria -- structures inside cells – and placed that time of the most recent common ancestor between 99,000 and 148,000 years ago. That agreement makes the new finding especially significant:
The research was done by a team of scientists from Stanford University, the University of Michigan Medical School, Stony Brook University, and their colleagues, and is published in the journal Science. The team hopes their work will lead to further research on Y chromosomes as vehicles for studying human history – and tracing male lineages back to the common "Adam" ancestors.
Jeffrey Kidd, Ph.D., an Assistant Professor of Human Genetics and Computational Medicine & Bioinformatics who worked on the new study, notes that only recently has it become possible to sequence Y chromosomes, because of technical limitations of previous approaches. The new paper details how the team was able to make reliable measurements of the sequence variation along the Y chromosome – which is handed down only from father to son without exchanging, or recombining, genetic material with other chromosomes.
Kidd notes that this initial paper on Y chromosome sequence diversity provides important first evidence that the male most recent common ancestor did not live more recently than the female most recent common ancestor
"We're interested in understanding the historical relationships between many different human populations, and the migration patterns that have led to the peopling of the world," he explains in the August 1, 2013 news release, The when and where of the Y: Research on Y chromosomes finds new clues about human ancestry. "We hope that others will make use of this approach and sequence additional chromosomes of interest that are related to the peopling of specific places."
The study involved Y chromosomes obtained through the Human Genome Diversity Project, and from other sources. It included chromosomes from 69 men in several populations in sub-Saharan Africa, and from Siberia, Cambodia, Pakistan, Algeria and Mexico. The great migrations of our ancestors out of Africa, across Asian and Europe and into the Americas all helped shape today's populations – as did more recent forces related to colonialism and ever-growing global mobility.
Genetic studies such as this one may help anthropologists understand those migrations – and their timing – even better by giving them a genetic "clock" to use when studying today's humans, or potentially DNA extracted from ancient bones. It may also help scientists understand the great genetic diversity seen across Africa, and the evolution process that led to modern humans.
The reconciliation of the timing of "Adam" and "Eve", however, may be this study's most important immediate implication
"This has been a conundrum in human genetics for a long time," said Carlos D. Bustamante, PhD, a professor of genetics at Stanford and senior author of the study. "Previous research has indicated that the male MRCA lived much more recently than the female MRCA. But now our research shows that there's no discrepancy. In fact, if anything, the Y chromosome may be a bit older."
In addition to Kidd and Bustamante, the research team includes U-M's Elzbieta Sliwerska, Stanford's G. David Poznik, Brenna M. Henn, Muh-Ching Yee, Ghia M. Euskirchen, Alice A. Lin, Michael Snyder, and Peter A. Underhill, and Lluis Quintana-Murci from Institut Pasteur in Paris.
Funding came from the National Library of Medicine LM-07033, National Science Foundation DGE-1147470; National Institutes of Health 3R01HG003229 and DP5OD009154; Institut Pasteur, CNRS MIE, Foundation Simone et Cino del Duca. Several of the authors at Stanford report disclosures relevant to the paper. Jeffrey Kidd has no relevant disclosures.
Genetic study unravels ancient links between African and European populations
Check out the March 26, 2012 news release, based on a DNA study from Cold Spring Harbor Laboratory, "Genetic study unravels ancient links between African and European populations." Also see the article published in the journal Popular Archaeology, March 2012, "Study Shows Mixing Between Prehistoric Populations of Europe and Africa."
Researchers conclude from a recently completed study, published online on March 27, 2012 in the journal Genome Research that genetic material was exchanged between Europe and Africa as far back as 11,000 years ago, or more. In fact, many family history and genealogy associations who are fascinated by DNA-driven genealogy when the paper trail stops, can now trace their hidden African genes to the Roman Empire or to other conquests. Intermarriage or mating between different groups of people happened.
Also, there were migrations from Africa to Europe from not just between 72 generations ago to the fall of the Roman Empire and to medieval times as well--but also from 11,000 years ago. You may wish to check out the study, "Reconstructing ancient mitochondrial DNA links between Africa and Europe," Genome Research, published online, March 27, 2012.