February 14, 2013
to be posted on nobabies.net

Daniel Lord Smail
Robinson Hall
Room 218
35 Quincy Street
Cambridge, MA 02138
617 496 0149

Dear Dan Smail:
I received your book (Daniel Lord Smail On Deep History and the Brain, University of California Press Los Angeles 2008) from one of the most brilliant humans I have ever met.  I doubt he would be enthusiastic about what I am about to recount, but he certainly saw, as I would not have, the relevance to my own interest. 

First let me say your book did what I really didn’t think was possible any longer.  It scared me.  In the first three chapters you return to two themes: things are now changing very fast, and during the Paleolithic age things changed very little.  Without quite saying it you induce the thought, “Dark Age is the natural home of humankind.” 

Deep history.  As you say, let’s do it.  A million years ago a man dropped a rock.  A few years ago another man picked it up.  A single rock could be anything.  But the second man was looking for one because he already had found one.  Two means it wasn’t just a fluke.  The rocks in question were stone axes made by Homo erectus, or if you prefer ergaster.  They were not remarkable, being like other axes of the time.  The remarkable thing was that they were found on a Pacific island that was not accessible except by open ocean voyage since the time of the first human.  People traveled across the sea and established a community there.

If you can organize a voyage over the sea, get people and craft together with supplies necessary to the task and make it work, I think you can function in modern society.  The expansion of ergaster was most impressive.  Then they died out.  They died out all over Eurasia.  It wasn’t our fault.  Our species did not exist.  No natural disaster I know of did it to them.  They had a systematic problem that they could not solve.

When our own species came into existence, we had bigger brains than moderns do.  I have no reference and only read that once, but let’s go with it.  We are talking brain and we are talking deep history so you probably know if it was true.  If not, let’s go with it.  The brain had certainly been increasing beyond the already impressive brain of ergaster.  There was the Neanderthal expansion, but then they died out, too.  They had the biggest brains of all, so brain size isn’t everything.  But somehow there seems to have been a problem that needed a big brain. 

So first modern humans had brains bigger, and probably better, than Homer, Newton, Poe, Einstein … name your hero.  And since there must have been a problem, likely the brain was able to address the problem.

A giraffe will cease to grow a longer neck by the time there are no more leaves it cannot reach.  (Sorry for the aside, but the idea of a giraffe “stretching its neck” wouldn’t wash even if inheritance of acquired characteristics were not the dominant paradigm.  A giraffe can only exert force with muscles, or maybe by stepping on something.  Muscles pull.  Muscular action shortens the neck.)  So there was a task for the brain, and it was a big task.  It meant dealing with something that run amok would lead to extinction. 

As you say, it wasn’t tool use or hunting.  They had been going on since long before ergaster.  Well there is one and only one issue of such magnitude that it can wipe out a species over so great a range in the absence of obvious environmental catastrophe.  That is the matter of babies. 

“Babies?” I trust you snort.  “Nothing difficult about babies.  Dogs manage.  If it smells like it’s in heat, mount it.  Besides that big brain produces problems with bearing babies.”  Yes, it’s inconvenient.  But the issue is so important that the sacrifice was worth it … so far.  

You see, it’s a little known bit of biology, but in order to have sufficient babies to survive any animal population must have a degree of consanguinity. 

Don’t call for a straight jacket.  There is evidence.  Here’s the link.  It will take less time and mental effort to understand it than it takes to make your hundredth stone axe.  http://nobabies.net/A%20December%20summary.html

The difficulty with the problem is that the process takes a long time to work itself out.  If you were to take a group of people, and it needn’t be as many as a thousand, and contrive so that nobody marries anybody with the same ancestors going back to the start, that population will die out within ten generations.  At least that is where the evidence points.  Actually it’s probably five or six generations. 

So here is the double bind.  On the one hand, given a stone axe, a copse of trees and a motivated village after a morning of work you have a band of men with pikes, the weapon of Alexander, of Caesar, of Robert Bruce, of Napoleon, or Robert Lee.  Of course with the last two it was called a gun with a bayonet, but it was really a pike.  And Lee lost at Gettysburg because the breach loading rifle finally fulfilled the promise of the missile: hit the pike men before they get to you. 

I don’t know whether a hippopotamus could be killed with wooden pikes, but it doesn’t much matter.  Pike do poorly in deep water anyway unless you count harpoons.  An elephant might be a challenge.  But these animals evolved right along with humans.  Outside Africa and out of the water the pike reigns supreme until Gettysburg.  That wasn’t so long ago.  I knew my great grandfather who was a boy around there.  He shook hands with Lincoln the day of the address.

So there is one side of the problem.  Leave Africa and you are invincible.  You can, with your fellows, travel anywhere.  You can sweep to the ends of the earth.  But then … then you have to stop. 

As long as you are expanding, the founder effect is your friend.  You enter new territory with a few people and multiply.  Everyone is related.  Then another band detaches and moves on.  But once you lose your momentum, then the population grows, there is contact with adjacent groups and eventually consanguinity goes too low and you die out.

The cure is to keep within your group of kindred.  But that is very difficult.  You are talking, even at five generations, a process that takes more than any human lifetime to work its way out.  Experience is no help.  What’s worse, you really don’t understand what is hitting you.  Almost nobody understands to this day.  You must live with decisions made by people you never knew and make decisions for people you never will know.  Add to that the fact that people do what they feel the need to do.  This does not always mean what the information tells them would be the best idea. 

So the solution is to build up some Byzantine set of social reflexes, traditions, myths and whatever and have them such that when you apply them to real people under greatly varying conditions you come up, often enough, with a mating decision that would have been prudent if you only had the facts and the biological rules.

Even with the resources of the internet and years of dredging journals and asking experts, even with knowing the rules better – I feel sure – than anybody has ever known them I would be hard pressed to make a good decision in real life.  Working it out from a set of social norms? 

Now there is one way.  That is always to marry a first cousin.  Then you are likely to have all the facts at your disposal.  And that strategy does, indeed, seem to be viable for substantial numbers of generations.  But there is a price to be paid, I am told, with inbreeding.  That’s no problem if you are dealing with contemporary Americans.  The actual risk is small.  But I have seen arguments that I cannot counter with facts to the effect that first cousin marriages if obstinately continued, do cause significant trouble.

So a brain evolved to deal with this most vital of all issues.  And it worked for the many many years of the Old Stone Age.  Exactly what the rules and traditions were nobody knows, but you can be pretty sure they didn’t have much to do with Mendel and the concept of the race for speciation.  And I think it safe to say that the rules were imperfect so that tribes were lost on a regular basis and the rules discouraged the free flow of ideas that is needed for continuing technological progress. 

Against that, the Neolithic revolution is little short of a miracle.  Somehow they worked it out that the density of a farming population was just right so that if you were a peasant and married somebody within an hour’s walk things worked out OK.  But you had to have somebody to enforce the system, somebody to oppress the peasants.  They had to be oppressed, otherwise they would travel at will, marry whom they pleased from a broad social horizon and lose their consanguinity.  But of course the oppressors didn’t have anybody to oppress them so they died out with clock like regularity.  Check out that link I gave you.  You’re a historian.  Don’t you want to know what really drives history?  Do you doubt that fertility was a Neolithic obsession?  What kind of idols did they make? 

Then came the Bronze Age.  We had gods, endemic warfare, arrogant leaders, brutal taxation and widespread misery all around, so things were OK for a bit.  We had cities that displayed the treasures of civilization as a draw but where there were never enough babies and we had the peasants who were sufficiently consanguineous to provide a steady flow of recruits for the cities.  The elite kept crashing of course, but things were meta stable.  There was always a new empire or civilization ready to rise on the ashes of the old.

Then came those thrice accursed English with their Industrial Revolution and the notion that not everybody had to be miserable all the time.  Consanguinity and fertility are spinning around the siphon.  We have now exited history and entered the epilogue. 

What do you think?


M. Linton Herbert MD

I can report with joy that Professor Smail read the letter most closely and was big hearted enough to sent a prompt reply with some astute observations and questions.  I have expressed to him my profound gratitude.  Perhaps one day I shall ask his permission and post his answering letter. 

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