Post script to our wandering cousins (and their genetic streams)

Shortly after I posted about our wandering cousins, intrepid NYT science reporter Carl Zimmer posted story about a newly identified population called Ancient Paleo-Siberians:  The story is a lengthy one and I do not have the time to render it clearly here, but the gist is that geneticists looking at different populations in Siberia and in North America have found a complex story of migration, populations mixing, populations disappearing, etc.  By and large the current Siberians have little genetics in common with Siberians of the long past or with native Americans today.  Geneticists have found a group from 40,000 to 10,000 years ago that seem to have played some role in peopling the Americas called the Ancient Paleo-Siberians.  Current native Americans derive about 75% of their DNA from this group who have largely disappeared.

The geneticists and anthropologists and paleontologists are working on different explanations and wondering how to gather more data to resolve their differences. Very difficult to find fossils in that area, especially since after the last ice age the land bridge between Asia and North American is underwater and the rest is frozen.  But given the recent news stories I began to ponder the facts of populations arising and subsiding through multiple migrations back and forth.

In prehistoric times we are talking about changes over thousands of years; in modern times we are talking about days, months and a year or two.  The prejudices against breeding between groups may have lessened in some places but continues on in others, and I suspect that much of the reaction against migrants and refugees is more about sexual mixing than economic realities.   Immigrants contribute to social and economic vitality in short order, even making important contributions on many levels, so the complaints about them using resources etc. must be a smokescreen for other concerns, e.g., group racial identity.

Only problem there is that group racial identity is more a political instrument for gaining and consolidating power than a valid concern over any genetic differences which are at most miniscule.  So I wonder if Ancient Paleo-Siberians, Neandertals, Denisovans, Ancient North Siberians, Inuits and Mayans back in the day before their cultures established political structures and functions showed concerns over the influx of a new group.  Siberia to us seems rather forbidding but back in prehistoric times was a resource rich environment.  Plus there were just not that many people back then; the overcrowding we experience as normal was not known.  So long as hunting grounds were separate or even shared like the Native Americans did in our own valley here in SW Virginia, I doubt that many problems erupted.

Another pondering:  The story of Romeo and Juliet is iconic for the triumph and tragedy of love between groups. As our species evolved, when did emotional bonds and attachment surmount sexual attraction to become a dominant force in which the love between two people erased their concerns about group differences?  I think that was a great day in our history, even if different problems then arose.

One of the tropes characterizing modern times is the speed with which cultural change takes place, and I think that also applies to group mixing, whether ethnic or racial or cultural.  Groups adhere together only so long, whether it is a decade or a millennium, and then boundaries begin to blur and break down as they mix with another group. That seems to me a basic fact of life on Gaia.  Only physical isolation stops this process and even then not for long.

So when the nationalist cretins march to promote their own group’s solidarity (as they did in Charlottesville) and, by implication at least, superiority, I know that they are doomed to in-breeding catastrophes.  Indeed, they are already in-breeding catastrophes of the cultural sort.  Our hope is that humans continue as they have done since the dawn of our kind, wandering and meeting new people, learning and developing new ideas, and sharing the planet as best we can (which is better than we are doing now).  As always, travel on.

U R what U eat &

what you eat contributes to the evolutionary constraints on what genes bubble up in the gene pool and flow down to your progeny.  I had not planned on posting until after Thanksgiving (next post on the dialectical path)  but I think a report on a genetic study of old European bones deserves notice.  Here is one version from the NYT:

Researchers analyzed genes from 230 individuals who lived from2300 to 8500 years ago.  The earliest population were hunter-gatherers, previously studied from the oldest bones found from 45,000 years ago, and then about 8500 years ago agriculturalists from the Near East moved into Europe.  About 4500 years ago a group called the Yamnaya (new to me) moved west from the steppes of Russia.  The genes of this last group seemed to have increased the height of Northern Europeans.  One of the biggest findings though concerned the late rise of the gene responsible for lactose tolerance, about 4000 years ago, and it spread rapidly.  Further genetic changes ensued from a diet built upon wheat, including risk for irritable bowel syndrome along with the capacity to extract important proteins from the wheat.  And diet also helped shape the genetic changes for a shift to lighter skin color.  An enormous study when you consider the sample size and what it took to collaborate and gain access to all of the bones and then the analysis and comparison within the group over time and with moderns.  Wow!  And so Happy Thanksgiving.  Hope everyone has a safe holiday.


Does lobster salad in Ireland contribute to the rise of genes for a literate life? Yes!