Rethinking “Out of Africa”

Out of Africa

Neanderthals separated from humans, Homo Sapiens, about 400,000 years ago, but then, in Eurasia, the two species, who were believed to be unable to interbreed, came back together again, and did.  We know this because every population in the world, except for Africa, carries both Neanderthal and/or Denisovan DNA, including aboriginal people from Australia.  This information, newly discovered in the past year or so, raises a lot of thorny questions.

Neaderthals have been grouped as a separate species from Homo Sapiens, modern man, and members of two different species, by definition, are not supposed to be able to interbreed and have fertile offspring.  So are Neanderthals and Homo Sapiens really the same species?

Neanderthals, as a separate species became physically extinct about 30,000 years ago, at least we can no longer find fossil records of them.  But did they really, or did they simply assimilate and genetically, and physically, become the new us?

And if that wasn’t enough, there are the Denisovans and they too interbred with Homo Sapiens.  In fact, Denisovan and Neanderthal bones have been discovered together, and Denisovans are believed to be an offshoot of Neanderthals.  And what about the Hobbits of Flores Island?  Where and how do they fit in?

And there are probably more surprises that await us, because there are more fossilized bones that we have not been able to obtain DNA from that don’t match any of the groups mentioned above.  In the future, discoveries of fossilized bones will likely be made that from which we will be able to recover DNA, as the recovery techniques improve.

But what does all of this mean?  How does it affect what we knew, or thought we knew, about the “Out of Africa” theory that says all contemporary man evolved in African, left Africa and subsequently killed off or replaced all of the other species, such as Neanderthals?  If that’s not true, what is true?  Did we evolve out of African several separate times, getting reacquainted some several 10s (or hundreds) of thousands of years later on another continent?

All of this unexpected mixture causes lots of questions, and today, we don’t have many answers.  But maybe the biggest question is that of what, exactly, is a modern human?

CHRISTOPHER STRINGER is one of the world’s foremost paleoanthropologists. He is a founder and most powerful advocate of the leading theory concerning our evolution: Recent African Origin or “Out of Africa”.  He has worked at The Natural History Museum, London since 1973, is a Fellow of the Royal Society, and currently leads the large and successful Ancient Human Occupation of Britain project (AHOB).  His most recent book is The Origin of Our Species (titled Lone Survivors in the US).

Here’s what Christopher has to say:

“At the moment, I’m looking again at the whole question of a recent African origin for modern humans—the leading idea over the last 20 years. This argues that we had a recent African origin, that we came out of Africa, and that we replaced all of the other human forms that were outside of Africa. But we’re having to re-evaluate that now because genetic data suggest that the modern humans who came out of Africa about 60,000 years ago probably interbred with Neanderthals, first of all, and then some of them later on interbred with another group of people called the Denisovans, over in south eastern Asia.”

To read more of Christopher’s thoughts, click here.  They are very interesting and enlightening indeed, from a man who has been in this field since the beginning, a mere 40 years ago.

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

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Autosomal Testing Comparison

Currently, there are four different entities, 3 corporations and a nonprofit, that test autosomal DNA using the newest technology, the Illumina chip.  There are different features and functions of each one.

I am describing them below in broad terms, and including links to articles where I and others have discussed their autosomal products.

23andMe – The first company to enter the chip based world of genetic processing by introducing a health traits and genealogy product that provided genealogists with cousin matches and percentages of ethnicity.  They provide raw data files that can be downloaded and then uploaded to Family Tree DNA and GedMatch.  In December 2012, after a significant capital investment, they dropped the price of their autosomal product to $99 with a goal to reach one million customers as a result.  They currently have about 180,000.

http://dna-explained.com/2012/12/07/new-worldview-at-23andme/

Family Tree DNA – Clearly the leader in genetic genealogy testing, they offer the Family Finder test using the same chip based platform as 23andMe.  Customers of 23andMe can upload their raw data file to Family Tree DNA for $89, effectively allowing them to fish in both pools for cousin matches and to obtain the ethnicity predictions from both companies.  Family Tree DNA provides raw data files and numerous tools to assist the genealogist, including integrated searching of autosomal, Yline and mitochondrial matches.  The Family Tree DNA Family Finder product is currently $199.  Family Tree DNA customers are generally interested in genealogy, while 23andMe clients are often only interested in the health traits aspect of their test.

http://dna-explained.com/2012/10/14/what-to-order-geno-2-0-vs-family-tree-dna-products/

Ancestry – Ancestry introduced their AncestryDNA test in early 2012 by initially giving away tests, then selling tests for the reduced price of $99 to build their autosomal data base.  Today, the tests range from $129 to $199 depending on whether or not you have an Ancestry.com subscription.  Continued, complete access hinges upon maintaining a subscription at some level.  Their test reports cousin matches and percentages of ethnicity.  If your matches have attached their genealogy, and it’s not marked private, you can see if you share common ancestors by viewing their tree.  Ancestry’s ethnicity predictions have significant issues, they provide no autosomal tools, such as a chromosome browser for cousin matching and they do not provide your raw data to download, although they have said they will provide that sometime in 2013.

http://dna-explained.com/2012/10/24/ancestrys-mythical-admixture-percentages/

http://dna-explained.com/2012/09/10/ancestry-autosomal-results-are-back/

http://www.isogg.org/wiki/AncestryDNA

National Geographic Genographic 2.0 – The latest autosomal test to be released is focused somewhat differently that the other tests.  This test looks more at deep ancestry using the discoveries made within the Genographic project over the past 6 years.  This test provides the deepest clade testing for the Y chromosome available from any test at any company.  It also provides ethnicity percentages based on many newly discovered SNPs not in use elsewhere.  The price is $199.

http://dna-explained.com/2012/07/25/national-geographic-geno-2-0-announcement-the-human-story/

http://dna-explained.com/2012/07/26/geno-2-0-qa-with-bennett-greenspan/

http://dna-explained.com/2012/07/30/geno-2-0-answers-from-spencer-wells/

http://dna-explained.com/2012/12/11/geno-2-0-results-first-peek/

http://dna-explained.com/2012/12/12/geno-2-0-results-kicking-the-tires/

In addition, Debbie Kennett has added a wiki page about comparing autosomal testing companies in the ISOGG Wiki at:

http://www.isogg.org/wiki/Autosomal_DNA_testing_comparison_chart

Thanks Debbie for your efforts to help everyone!

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

2012 Blog in Review

I want to take this opportunity to thank everyone for following and reading my blog this year.  I launched www.dna-explained.com in July, so this annual report is only for 6 months.  The blog had an amazing 85,000 views from 137 countries in 6 months.  Not bad at all.  If you’d like to see more, like which posts were the most popular and who posted the most comments, the WordPress.com stats helper monkeys prepared a 2012 annual report for my blog.

Here’s an excerpt:

19,000 people fit into the new Barclays Center to see Jay-Z perform. This blog was viewed about 85,000 times in 2012. If it were a concert at the Barclays Center, it would take about 4 sold-out performances for that many people to see it.

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research