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:  https://www.nytimes.com/2019/06/05/science/native-americans-genetics-siberia.html?action=click&module=Well&pgtype=Homepage&section=Science.  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.

Humans do wander and seek

Our ancestors wandered far and wide, seeking something new, and these migrations had consequences for our genetic pools.  I have seen several reports of an archeological find in China (https://www.nytimes.com/2018/07/11/science/hominins-tools-china.html.  Check out the cliff the archeologists had to scale for this research) of tools estimated to be around 2 million years old.  This means that one of our ancestral lines left Africa much earlier than previously thought and traveled 8,000 miles east.  These are categorized as hominins, precursors to genus Homo, but still bipedal with a brain beginning to enlarge.  Paleoanthropologists have found fossils in China of Homo erectus that are 1.6 million years old.  Fossils of hominins in Africa date back to over 6 million years ago.

Repeated migrations over the aeons carried different genes to different populations.  Consider the gene for lighter skin colors that spread in northern populations or the genes enabling lactose digestion that appeared in Europe that spread in a variegated manner.  My favorite is a gene first identified in the Denisovans from central Russa that some migration carried to Himalayan populations; this gene helps form the special type of hemoglobin that enables better adaptation to life at high altitudes (see post 7/4/14). I have wondered if some of the peoples that escaped to live in the high Andes also had such a gene.  I say ‘escaped’ because of a find of a small site from ancient times in the Andes where life would not have been easy because game and edible plants were sparse. (See post 10/27/14) Why live there?  The best hypothesis would seem to be escape from another tribe whose aggression was unbounded.  Anyway, our ancestors clearly wandered the land over many generations seeking opportunities and avoiding negative exigencies.

I have been reading some research by Shinobu Kitayama and colleagues that is quite interesting about the cultural differences between Asian and American peoples. These seem to be fairly well established by multiple lines of research with different samples and different methodologies.  In brief people from Asian cultures see themselves and the world as more interdependent (Americans see it as more independent), focus more on context than on a lone figure, define the self in relation to social relatedness rather than individual achievement, seek to accommodate rather than to be an agent of social change, de-emphasize individual achievements by focusing on their own faults and attributing success to social connections, think holistically rather than linearly, etc.  Looking at this list you can see that Americans are quite different culturally, thinking linearly, highlighting personal achievement, valuing competition and social friction a bit more, etc.  Just to speculate a bit more based on some lectures on Eastern intellectual traditions by Grant Hardy, the Western endorsement of desert monotheism and the Eastern endorsement of ancestor worship along with values of social order and justice that are accompanied by a flexible notion of deity would seem to reflect our different cultural ways of thinking evident 2-3000 years ago.  Dr. Hardy says Christian efforts to convert China failed when the Pope and the Dominicans condemned ancestor worship as idolatry.  That turned out to be an unacceptable violation of cultural mores and did not fit with the Asian understanding of what a deity is, so they rejected missionary efforts (and then the British gunboats showed up).

Kitayama and colleagues have begun to study how acculturation leads to changes in the brain, so that different cultures lead to different brain organization, thus the cognitive differences noted above.  These differences arise from genetics to developmental epigenetics and acculturation experiences early on life.  This makes perfect sense.  The question arises for me of how migrations have contributed to these differences and how once the differences were initiated the differences became self-sustaining.  Many peoples have revered their ancestors; the Chinese have maintained that even in the face of Christian zealousness.  Certainly part of the answer here is the lack of intermarriage and the protection of the gene pool through isolation.

Consider one final example cited by Kitayama.  Some significant percentage of Americans has a gene allele that promotes increased impulsivity and risk taking; this may contribute to a higher incidence of ADHD (as well as substance abuse, etc.?).  This allele is virtually unknown in the Chinese population. Should there be more intermarriage, that might change.  Why do we have that allele, or how did our migration pattern contribute to its presence? That brings to mind an old joke told at psychology conferences years ago.  A prominent ADHD researcher, in the effort to make fun of the image of Californians, speculated thusly:  The Europeans who populated North America were rebellious, impulsive risk takers—who else would sail across the Atlantic in small ships on a perilous voyage?  And then from that population the even bigger risk-takers, impulsive people migrated west, so that Californians represented a genetic ‘distillation’, as it were, of impulsivity.  Ha-ha.

Jaak Panksepp in Affective Neurosciencedocuments quite clearly how our mammalian heritage includes a proclivity for exploring in our neural systems for seeking and anticipating.  Like a good many traits we have accentuated I think humans have a rarefied impulse to go beyond; this involves some risk but the species that spread across the globe and then went to the moon can manage a good deal of risk. Humans do wander and seek.  We intermarry and that contributes to the flow between gene pools.  We don’t intermarry and otherwise conserve our cultural heritage.  Asians are indeed different than Westerners.  As a member of the latter group, I think we could learn a thing or two from the former, e.g., mindfulness, the greater value of interdependence, the importance of contextualized thinking, etc.  But for now I will travel on.

 

Triangulating 3 reports

I find myself somewhere in the noosphere and will use three news stories to triangulate my location. The noosphere, if you recall, is a term from Teilhard de Chardin’s writings. He thought it a last stage in human evolution leading up to the omega point where and when we merge with a god of some sort. Alas, that teleology is unsupported by anything other than mystic wishing, so instead the noosphere is better defined as the sphere of human knowledge, and like our atmosphere, is full of local events. To find my place today I consider three stories, one about an ancient event, one about a modern one, and one about the genetic flow streaming down to our genome.

The ancient story is from the NYT about cave paintings in northwest China that indicate the people some 10,000 years ago used skis for winter transportation. The current people there who keep the old ways still make their own skis in the traditional manner, splitting and planing narrow planks, then boiling one end to help curve it upward for easier traverse. Of course the Chinese government is now exploiting the region by building huge ski resorts so the old timers watch their way of life fade. Prior to this find cave paintings in Scandinavia indicated that people there skied 8,000 years ago. This is instrumental skiing, not for sport but for hunting and transportation. (I don’t know when the sport sort appeared.) It is a good story: https://www.nytimes.com/2017/04/19/sports/skiing/skiing-china-cave-paintings.html   If you want to see a movie about hardy, self sufficient people who make their own skis, try Werner Herzog’s well done documentary Happy People: A Year in the Taiga, very worthwhile viewing. The ingenuity of our species is really remarkable.

And speaking of that, the modern story is that in the next few days, the Cassini spacecraft will begin a series of maneuvers between the rings of Saturn, eventually to fly into the planet itself. More than a decade in design and construction, Cassini launched in 1997 and traveled millions of miles flying by Venus and Jupiter on the way, indeed using Jupiter’s gravity to sling around and pick up speed, before arriving at Saturn in 2004. In December 2004 Cassini released a probe, name of Huygens, that landed on the moon, Titan. Huygens sent back data to Cassini that relayed it back to earth. Since that time Cassini has been assaying Saturnian phenomena and now its nuclear fuel is running out so the last data will be collected on a suicide mission. Over 13 years of data gathering! That is truly remarkable ingenuity. Consider one more detail. Huygens landed on Titan within a kilometer of its planned site 1.2 billion kilometers away from Earth after a 7 year trip. Some people with excellent math skills worked together very hard to accomplish something incredible.

And speaking of working together, Carl Zimmer of the NYT does a fine job summarizing some well done research into the genetic influences on monogamy: https://www.nytimes.com/2017/04/19/science/parenting-genes-study.html  Briefly, scientists found two closely related mouse species, one monogamous and one polygamous, and through a diligent methodology explored the influence of parenting behaviors in contrast with genetic influences and then isolated some of the genes definitely influencing mating styles. Males in the monogamous mice participated more in constructing elaborate nests and in nurturing the young, keeping them warm, clean, and safe in the nest. The other mice built less elaborate nests and the males did less parenting. Going further (how long did all this take? I don’t know but a good while I am guessing), they found a genetic loci that controlled the use of a hormone, vasopressin, and then injecting vasopressin into the polygamous males found they increased their parenting participation to be like the monogamous males. Remembering from one of my favorite texts, Jaak Panksepp’s Affective Neuroscience mentioned here many times, I think vasopressin plays a variety of roles in the hormonal system that also includes oxytocin, a well known stimulator of parenting and prosocial behavior.

Triangulating these three stories we find a place in the Noosphere where humans, neither monogamous nor polygamous but certainly parental, work ingeniously to survive in different locales and climates and also to work together in a long term committed fashion to explore our universe and contribute mightily to the Noosphere. We should, given an ethics of knowledge (following Monod), be able to govern ourselves better than we seem to be doing at this moment. Travel on.

Bird song learning and human language genetics

Yesterday’s email from Earthsky.org contained links to good summaries of a series of papers recently published about the genetic similarities underlying bird song learning and human language.  The science reported here is of an unprecedented scale as many researchers in many universities analyzed the genome of over 40 bird species thereby providing a comprehensive map of the evolution of various bird species and which genes contributed most to song learning.  Then these results were compared to analyses of the human genome’s contribution to speech.  These studies required new computational algorithms run on super-computers because of the size of the data set.  Wow!  And wouldn’t you know it, we share many of the same genes that control vocal performance.  Here are some links:

http://earthsky.org/earth/genes-link-birdsong-and-human-speech?utm_source=EarthSky+News&utm_campaign=bbb57cbd60-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-bbb57cbd60-393591545

http://earthsky.org/earth/video-probing-the-big-bang-of-bird-evolution?utm_source=EarthSky+News&utm_campaign=bbb57cbd60-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-bbb57cbd60-393591545

http://www.nsf.gov/news/news_summ.jsp?cntn_id=133524&org=NSF&from=news

So I am thinking back to 2 earlier posts in June, 2014, on the biological roots of language that discussed how two evolutionary streams from birds for the melody and silver gibbons for the words may have contributed to the confluence resulting in human language.

silvergibbon

As reported in the last link above from the National Science Foundation, modern birds appeared around 66 million years ago after a meteor strike eliminated dinosaurs and much other life.  Birds came through that holocaust and then underwent an evolutionary explosion into the many forms around today.  Mammals also came through that holocaust; their evolution has been less explosive perhaps but seems more extensive and progressive when thinking in terms of brain complexity. Primates have been around almost as long.  Less is known about the evolution of gibbons but they seem to have appeared in current form somewhere around or before 8 million years ago.  Homo sapiens or our ancestral species appeared only around 500,000 to 200,000 years ago.  So these genes we have in common with birds have been around, replicating themselves over and over and over again, a very long time.  What has changed, then, I guess, would be their context, the genes surrounding them, and these presumably led to increased empathic capabilities and to symbolization.

Wikimedia

Wikimedia

Some of the best song learners, vocal mimics, are parrots and they have been found now to have evolved with particularly powerful song learning ability.  They are monogamous and some mate for life.  Oddly (perhaps), gibbons share these features.  At the least this suggests that the evolved genetic context for vocalization genes supported more stable social relationships and with mammals this led to increased empathic capacities.  I think this suggests something else as well.  In his book, The Selfish Gene, Richard Dawkins floats the suggestion that some species, because of their particular genome, are more evolvable than others.  In learning about these recent studies I was struck by how birds have diversified over the past 66 million years into several thousand of species but they do not seem to have developed any great new abilities.  Mammals have also diversified (and let’s not bring insects into this) and they have developed the prerequisites for greatly increased cognitive and social organization.  Do mammals, especially the lines leading to cetacea and primates including hominids, have greater evolvability than birds?  Looks like it, and I cannot resist this speculation.  As I mentioned in the June, 2014, posts, birds and mammals have different embryological development.  All bird embryos start out as male and some are feminized through hormonal production.  All mammal embryos start out as female and some are masculinized through hormonal production.  Is starting female associated with more evolvability and starting male more limiting?  That might be a new twist in gender inequality, eh?