Tag: hominins

Eloi to Silicon-Morlocks

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I find archaic human paleoanthropology fascinating.  The impact of better radioactive dating methods and now, DNA analysis has had a remarkable effect on the state of our knowledge.  Previously poorly-dated specimens were used to justify very late dates for when Homo sapiens, his predecessor H. heidelbergensis and the even earlier H. errectus left Africa.  More accurate information leaves it an open question whether sapiens evolved in Africa or Eurasia.  And the presence of H. neanderthalensis and H. denisoviensis and possibly other sister species of H. sapiens scattered around in Eurasia makes the point even more acute that our species radiated and developed and then remixed inside of Eurasia.  And the fact that all traces of Neanderthal and Denisovan DNA are lacking completely in Africa only highlights the fact that Africa became a sort of isolated group of populations separate from the evolution that was taking place to the north.

What strikes me as very interesting is just how quickly humans change in reaction to their environment.  Just look around at the appearance of modern humans the world round.  Various types of Africans, Northern Europeans, Southern Europeans, Middle Easterners, South Asians, East Asians, the Australian aborigines and the New Guineans, the Native Americans, the South Sea Islanders and many other groups have differentiated from each other over the course of not millions of years but thousands.  Our hair, eyes, skin, the shapes of our faces and many other traits have changed in order to adapt to our environments.  Even something as fundamental as blood types are affected.  We are an adaptable species.  And I think that because of human squeamishness we have been less than logical with our designation of what is a species, subspecies or race when it comes to man.

After all, we’ve managed to crowd all of the “races” of man into one species without the thought of sub-specifying ourselves.  But the Neanderthals and Denisovans (whom we know bred with humans) we kick into separate species altogether.  That seems a bit much.  I remember in old books we sometimes saw Homo sapiens neanderthalensis as a subspecies of ours.  Surely our “kissing cousins” deserve at least that small a consideration for providing us with a few percentages of our genetic material (not to mention red hair!).

In general, I’m not willing to toss any of our closest relatives under the bus.  H. heidelbergensis and H. errectus were present in Eurasia for a very long time along with these later editions and what seems reasonable is that the same kind of interbreeding and intergradations occurred at earlier times spawning other “species” of Homo that we either can’t distinguish or haven’t found yet.  And whether these archaic humans met in the Mediterranean or the more northern regions the same kind of mixing and changing was going on.

So, man is ever-changing and since our brain is our defining facet it makes sense that changes in our brains is where we’ll see evolution hard at work.  The only question is whether this evolution will be untrammeled or will it be directed.  Artificial intelligence is the prize that technologists and industrialists tout as the future.  Will our brains be replaced with silicon?  Will we be turned into zoo animals that eventually will be euthanized when we’ve been rendered powerless?

I tend to think not.  I’m betting on the hominins.  For all our bad habits and shortcomings (and there are many) I think there is a greatness in our line.  I think we can still find our purpose on this planet.  And I don’t want to disown any of our kin here on Earth.  We fight each other and hate each other for our differences and just because we want each other’s stuff.  But that is part of being human.  We still have time to figure out a way to get along regardless of all our differences.  And as our brains get stronger so we will.  We have some important fate ahead of us.  And I doubt that it involves becoming Eloi to Silicon-Morlocks.

What Keeps Us Human

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I’ve been reading the latest analyses of paleolithic hominin DNA and from what I’ve gathered it seems to be the case that the present human population is a non-homogeneous collection of various hybrid populations between Homo sapiens (“modern” humans) and Homo neanderthalensis, Homo denisovensis and very likely Homo erectus.

Of course, human evolution is such a hot-button topic today that getting paleontologists to use words like hybrids to describe human lineages makes them squeamish and nervous.  Everyone is afraid of the accusation of racism to erupt if someone hints that human beings of different ancestries aren’t all exactly the same.  But they really should all calm down.  Hominin species have been walking the Earth for something like seven million years and during that time various groups have become isolated, evolved different characteristics and then just as easily recombined and formed hybrids that in turn become isolated and start the process all over again.

The latest information I’ve seen shows that there is a strong correlation between Neanderthal DNA and modern populations in northern Europe and northwesten Asia.  And there are strong correlations between Denisovan DNA and modern populations of Australian aborigines and Papuan New Guineans.

The ancient DNA that has been found is restricted to specimens that existed in cooler climates so the complicated story of hominin mixing and isolating in Africa and other tropical areas may never be reconstructed (although recent work with fossil protein materials may change that in the future).  But I think it’s clear that humans have in the past and will continue in the future to recombine their populations in various ways in reaction to local conditions that select for fitness.

Of course, those selection pressures have changed drastically over the geologic time our genus has existed.  Human society has also evolved and culture has as much to do with evolution now as climate had in the past.  Human behavior is now dictated by things like propaganda, government policy, industrial planning, resource scarcity and even internet influencers.

But hopefully men and women will still try to find mates that will allow their offspring to have the best chance of surviving and carrying on the race.  It still makes sense for a man to want a woman with empathy for his children and enough sense to teach her children to obey their parents and follow the simple rules written on those stone tablets that have guided our civilization for the last several thousand years.

And it makes sense for a woman to want a man who isn’t too lazy or selfish to provide for his family and who enjoys coming home from the hunt and retires to the fire in his cave and tells his little tribe about the mammoth that he hunted and the saber-tooth tiger that hunted him.  And draws a picture on the walls of his cave to celebrate that story.

And the most important trait that both men and women should be selecting their mates for is their minds.  Our brains have been our hallmark for millions of years.  Homo habilis; the tool maker.  That’s us.  We’re the monkeys that came down from the trees, stood up straight and looked at the world straight on and began changing it to our liking from day one.  Fire.  The wheel, the wagon, the chariot, the ship, the saddle, the plow, the heat engine, automobiles, airplanes, rockets. Stone weapons, saws, knives, hammers, axes, levers, firearms, lasers.  Gold, silver, copper, tin, iron, steel, uranium, the atom bomb, the hydrogen bomb.  Wheat, oats, millet, rice, maize, cattle, horses, sheep, goats, donkeys, chickens, ducks, white mice, guinea pigs, rhesus monkeys, yeast, mammalian cell culture, CRSPR gene editing, bioengineering.

Let’s just hope that our “civilization” never forgets what keeps us human.

Dragon Man – The Human Family Tree is Getting More Crowded and More Interesting

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A recent report describes a very well preserved skull that was discovered in China in the 1930’s during the Japanese occupation and hidden away until the last couple of years and then handed over to paleontologists.  It is believed to be the skull of one of the species of human relatives of modern man.  It is a “hominin” species that is being described as Homo longi, or Dragon Man.

The skull is very reminiscent of the Neanderthal Man skull although it seems even closer to modern man in ways.  It has the prominent eye ridges, larger teeth and large brain cavity that characterizes Neanderthals.  But the face is flatter, the jaw more human-like.

What is in dispute is whether this represents a complete skull of the Denisovan Man.  The Denisovans were another early human species whose remains and DNA have been found in Siberia and Tibet.  The fossil evidence available is currently very limited.  It consists of a few finger bones and a small amount of jaw and teeth.  But interestingly, there is enough DNA material available to show that Denisovans have left some of their DNA in us and in fact cross-bred with both humans and Neanderthals.

The speculation is that the first homo sapiens or its close ancestor reached the north and split into two populations the Neanderthals ended up in Europe and the Near East.  The Denisovans went East and inhabited Asia.  And this is a simplification because there are several other species of hominins that were still extant in Eurasia.  Homo erectus, H. luzonensis, H. heidelbergensis and H. naledi existed in that same period of time (from a million years ago to fairly recently).

Later waves of Homo sapiens would then meet up with this first wave and then coexist, compete, mix with and ultimately displace these near relatives.  What is clear from this story line is that humans have constantly evolved to adapt to their changing environment as they migrated from Africa to Eurasia.  What is less comfortable for people today to discuss is the amount of genetic diversity that exists in the family of man.  In any other animal group, we would describe the existing races of man as species, or at least subspecies, that intergrade into each other at the edges of their geographical ranges.  And of course, the reality of the cosmopolitan nature of modern human civilization means that all these subspecies are rapidly mixing to form new variations.  And what the DNA evidence has shown us is that the migratory tendencies of human groups have repeatedly stirred the pot of human genetic groupings.  When the people that would become the ancestors of the Indo-Europeans began their treks westward and eastward, they spread their language and their genetic material from India to Britain.  Similar migrations have occurred right into nineteenth century with the colonization by the Europeans around the world.  And the present mania over diversity has further mixed things up.

But regardless of the semantic description of human genetics, it is fascinating to see just how dynamic our lineage is.  Apparently, the changes in terrain, climate and food resources have quickly selected for changes in the human form and physiology.  Some people have claimed that human technology has now eliminated the possibility of human physical evolution.  But that is simply not true.  In the last ten thousand years the human brain has evolved based on selection for complex thinking needed in more complex human societies.  This leads to further refinements and selects for individuals that can survive and thrive in the complex and changing environment that is our human world.  What this tells us is that we become what we need to be in order to adapt to our environment.  What this tells me is that we need to choose wisely how we organize our society.  It would be a shame to see our remarkable species end up as an ant colony.