<img loading="lazy" decoding="async" class="alignright size-full wp-image-6003" title="bushmen" src="https://blog-api.23andme.com/wp-content/uploads/2010/02/bushmen.jpg" alt="" width="350" height="232" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/02/bushmen.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2010/02/bushmen-300x199.jpg 300w" sizes="auto, (max-width: 350px) 100vw, 350px" />Group of hunters from the Ju/’hoansi tribe in the Namibian Bush/ Stephan C. Schuster
Researchers from Penn State University, the University of New South Wales in Australia, and the Baylor College of Medicine have sequenced the genomes of four individuals from different groups of the click-speaking San of southern Africa, as well as of Bishop Desmond Tutu of South Africa.   Their results, published online yesterday in the journal <a href="https://dx.doi.org/10.1038/nature08795" target="_blank" rel="noopener">Nature</a>, are providing striking new insights into human genetic diversity.
Joanna Mountain, 23andMe&#8217;s Senior Director of Research, has been studying the genetics of click-speaking peoples of Africa for over ten years.   Dr. Mountain said the new study &#8220;has demonstrated that any two San individuals are as genetically different from one another as a European and a Chinese individual. Clearly the linguistic diversity of the San is matched or even exceeded by their genetic diversity. Furthermore, even though the San Bushmen are often described, even by this study&#8217;s authors, as the &#8216;oldest known lineage of modern humans,&#8217; the new genetic data reveal that the San have evolved genetically as much as any group, partly through the random mutations that occur over time, but also through changes that enabled them to handle their often challenging, exceedingly dry environment.&#8221;
Read more about this study:
<ul>
<li><a href="https://www.nytimes.com/2010/02/18/science/18genome.html" target="_blank" rel="noopener">New York Times</a></li>
<li>Technology Review</li>
<li>Not Exactly Rocket Science</li>
</ul>

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Southern African Genomes Sequenced

<img loading="lazy" decoding="async" class="alignright size-full wp-image-4053" title="Biology experiment on well plate" src="https://blog-api.23andme.com/wp-content/uploads/2009/07/istock_000004124815xsmall.jpg" alt="" width="283" height="424" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/07/istock_000004124815xsmall.jpg 283w, https://blogcms.23andme.com/wp-content/uploads/2009/07/istock_000004124815xsmall-200x300.jpg 200w" sizes="auto, (max-width: 283px) 100vw, 283px" />
Using a research method very similar to the one used in 23andMe&#8217;s <a href="https://www.23andme.com/ancestry/origins/" target="_blank" rel="noopener noreferrer">Global Similarity</a> advanced view feature, researchers have discovered that most of the embryonic stem cell lines currently studied by researchers are derived from European and Middle Eastern populations.
Only two out of 47 were derived from egg and sperm coming from people with East Asian ancestry.   None of the embryos had genetic makeup indicative of recent African ancestry.
&#8220;Embryonic stem cell research has the potential to change the future of medicine,&#8221; said Sean Morrison, director of the University of Michigan Center for Stem Cell Biology and one of the study leaders in a press release.   &#8220;But there&#8217;s a lack of diversity among today&#8217;s most commonly used human embryonic stem cell lines, which highlights an important social justice issue.&#8221;
The researchers analyzed the stem cells using a SNP chip much like the one used by 23andMe for its Personal Genome Service.   The genetic data of each stem cell line was then compared to the DNA of a set of publicly available reference individuals from 63 populations around the world.
The analysis, published recently in the<a href="http://content.nejm.org/cgi/content/full/NEJMc0910371" target="_blank" rel="noopener noreferrer"> New England Journal of Medicine</a>, not only showed that there was a lack of ethnic diversity in the stem cell lines, but also revealed that at least five pairs of stem cell lines were likely derived from the same egg and sperm donors — genetically speaking, the equivalent of siblings.
&#8220;Efforts to derive and disseminate new stem cell lines should now emphasize underrepresented populations, to allow researchers to assess the extent to which ancestry of stem cell lines influences disease models, cellular therapies, and drug screening with the use of stem cells.
Availability of more diverse lines will reduce the risk that the potential benefits of stem cell research will be limited to patients with certain ancestries,&#8221; the authors write.
The use of embryonic stem cells in research is controversial.
In 2001, President Bush banned the use of federal funding for any embryonic stem cell research using cell lines other than the 21 that had been created prior to that date.
In March 2009, President Obama reversed this policy.   Derivation of new embryonic stem cell lines, however, is still not permitted using federal funds.
An alternative to destroying human embryos to create stem cells may lie in a new method in which adult cells are returned to a stem cell-like state through genetic manipulation.
These &#8220;induced pluripotent stem cells&#8221; avoid many of the ethical and moral issues surrounding embryonic stem cells, but it is not yet clear if they are suitable for all types of research.   Still, the University of Michigan based authors of the current study suggest that another way to increase diversity in the cell lines used for stem cell research is to create induced pluripotent stems cells from donors with diverse ethnic backgrounds.

Genetic Analysis Demonstrates Lack of Ethnic Diversity in Embryonic Stem Cell Lines Most Commonly Used In Research

<img loading="lazy" decoding="async" class="alignright size-full wp-image-2577" title="istock_000003625368xsmall" src="https://blog-api.23andme.com/wp-content/uploads/2009/01/istock_000003625368xsmall.jpg" alt="" width="300" height="199" />
Not all bacteria are bad.   Sure, there are plenty of nasty bugs that can make life pretty unpleasant; the ones that cause leprosy, anthrax, and cholera immediately come to mind.
But there are also plenty of beneficial bacteria  living inside of us that we may not even know about. Some of them help us synthesize vitamins, digest milk protein, and even stop other, more harmful microbes from infiltrating our immune system.
Many of those bacteria are so tightly connected to their human hosts that they can even be used to answer questions about our ancient ancestors. It might sound far fetched, but in a new study published in this week’s <a id="c.68" title="Science" href="http://www.sciencemag.org/" target="_blank" rel="noopener">Science</a>, an international team of scientists has managed to do this by analyzing a specific kind of bacteria hidden in the digestive system of nearly half the world’s population.   It is their hope that, by doing so, they can finally shed new light on how and when the first humans set foot on the Pacific islands.

Unearthing the origins and prehistory of the inhabitants of such islands as New Guinea, Samoa, and Polynesia has been no easy task.   Archaeological evidence has been spotty, due to the poor preservation in the tropical climate, while genetics has often been unable to distinguish between ancient migrations and more recent, historical movements.   As a result, researchers have begun turning to other disciplines to help fill in the gaps left by the more traditional fields.   In this most recent case, scientists thought outside the box, using the bacteria Helicobacter pylori — or, more accurately, differences in the genetic code of Helicobacter pylori strains — to discover when various parts of the Pacific were colonized.
Helicobacter pylori (H. pylori) is a kind of bacteria in that it is present in about 50% of the world’s population.   This makes it the most widespread bacterial infection on Earth.   It lives in our stomachs, and is sometimes associated with ulcers or an increased risk for stomach cancer.   However, more than 80% of those infected with it never know it, which may be why it is so widespread.   In fact, scientists believe that an ancient strain of H. pylori was present in the stomachs of the first humans to leave Africa more than 50,000 years ago.   Over the many thousands of years, H. pylori evolved into distinct strains found in distinct geographic regions.   For example, one strain is only found in Europe, another only in Africa, and a third only in East Asia.   So, just as genetic anthropologists use differences in our DNA to trace ancient human migrations, so too have scientists used H. pylori to reveal how humans first colonized some of the most remote parts of the world.
The current thinking about how and when the Austronesian peoples &#8211; that is, people who speak one of the many languages of island Southeast Asia and Oceania &#8211; came to colonize the Pacific Islands is, to put it mildly, unclear. While the majority of archaeologists, geneticists, and linguists all agree that the Austronesian peoples probably began their journey in present-day Taiwan, the timing and speed of their movements towards the outer rim of the Pacific Islands is a topic of great contention.   So, the authors of this most recent study hoped that an analysis of H. pylori among modern-day Austronesians might give researchers new information to go on.
The authors collected samples of the bacteria from the stomachs of more than 200 individuals living in Taiwan, New Guinea, Polynesia, and dozens of other Pacific islands.   Using techniques similar to those used in human DNA studies, the authors were able to track the different strains of H. pylori back to their common origin: Taiwan, about 5,000 years ago.
But how do these results stack up to findings by other researchers?   Interestingly, a companion piece in the same issue of <a id="u23p" title="Science" href="http://www.sciencemag.org/" target="_blank" rel="noopener">Science</a> also examined the peopling of the Pacific, this time focusing on the linguistic history of the Austronesian peoples.   That study analyzed more than 400 languages in the Austronesian linguistic family, using the similarities and differences to figure out when and where the group originated. The results of this study also support an origin of Austronesian peoples in Taiwan about 5,000 years ago.   In addition, both studies argue that people expanded in a similar direction: from Taiwan eastward towards Melanesia, Oceania, and finally Polynesia and the Hawaiian Islands.
It is not hard to believe that both the study of H. pylori and of the Austronesian languages would have yielded a similar date of origin of the Austronesian peoples, especially as both studies used the same archaeological record as a point of reference.   What is intriguing, however is that both studies &#8211; independent of each other &#8211; also point to similar paths of expansion of the Austronesian people once they left Taiwan.
The conclusions of these studies are far reaching, most especially because they illustrate how seemingly unrelated disciplines can be used to tackle a single question about the past.   Noted Cambridge archaeologist, Professor Colin Renfrew, believes these methods &#8211; combined with the more traditional archaeological or genetic methods &#8211; allow us to see how our past is still &#8216;within us&#8217; today, whether it be in our genes, in our languages, or &#8220;the bacterial flora in our guts.&#8221;

DEI — Page 12

Southern African Genomes Sequenced

Genetic Analysis Demonstrates Lack of Ethnic Diversity in Embryonic Stem Cell Lines Most Commonly Used In Research

Thinking Outside the Box: Bacterial Genetics and the Peopling of the Pacific

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