Category Archives: archaeology

Calling for Submissions – I’m Hosting the 101st Four Stone Hearth

four-stone-hearth

The 101’st Four Stone Hearth Anthropology Blog Carnival is being hosted right here, by yours truly.  We’re looking for submissions of blog posts/articles in the following topic areas:

  • archaeology
  • socio-cultural anthropology
  • bio-physical anthropology
  • linguistic anthropology

If you’re a blogger, you’ve written a recent post in one of the topic areas above, and you’d like to get some extra traffic to your site make sure to submit your post to either me at

mail{at}nickhorton{dot}net

or to aferensis.

You can also nominate others, of course.

Also, please feel free to leave comments below about what you’d like to see, and if there is anything I can do to make you more likely to get interested in not only reading the Four Stone Hearth every fortnight, but participating in it as well.

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98th Four Stone Hearth – Anthropology Blog Carnival

stone-age-dildo

In this, the 98th Four Stone Hearth, there are a number of cool articles.  But, I think this one takes the cake: Stone Age Dildo Found in Sweden.  Wow …

Natufian Villages, Wisdom Teeth, and Probability

Natufian

Some of the earliest villages ever discovered were from the Fertile Crescent (modern day middle east).  The culture that inhabited these villages has been dubbed Natufian, and dates to around 12,500 BC.  Two of these villages, Hayonim and ‘Ain Mallaha were relatively close to one another.  At first it would have been reasonable to presume that these villagers bred with one another.  They were close and each one had relatively small populations.  But, it turns out they didn’t, and the reason has much to do with simple probability.

Well, that and wisdom teeth, or the third-molars. The Hayonim people had ‘agenesis’ of the third molar – that is, they never grew in.  But, the ‘Ain Mallaha group nearly all had their third molars. 

If it had been true that the two groups interbred, then we’d get a mixing of types – those that had wisdom teeth, and those that didn’t – in about equal proportions.   Therefore, since we don’t have that, there must not have been significant interbreeding.

Sounds reasonable enough.  But, how can I be so sure that IF there was interbreeding THEN the proportion of third molars would in fact be about equal in both groups (or at least spread around a bit more)?

To answer that question we need to go over what an “allele” is.

Alleles as Soda-Pop

allele-frequency Genes are complicated little buggers.  It isn’t so simple as “this gene codes for that trait”.  Any single gene comes in a number of variations. We call those variants ‘alleles’.

Think of 2 soda cans.  One of them is flavored cherry, the other is flavored grape.  What they have in common is that they are both soda.  The gene is the soda.  But, this gene comes in one of two flavors – or we can say it has two alleles – grape and cherry. 

So, an allele is like a flavor.  Sometimes, as is the case with eye color, a change in alleles is no big deal.  It really is much like a flavor in that it causes you no harm to have blue vs. brown eyes.  But, there are times when having a different flavor (allele) does matter, like in the case of polio. 

Humans are diploids.  That means that we all have two chromosomes.  We get one from our Father and one from our Mother.  Each of them gave us one allele of each gene, and our ‘genotype’ for that gene (that is, what type of that gene we got) is a pairing of the alleles.  But, here’s the rub.  Our parents each had two alleles of the gene, and we end up with two.  How many possible choices were there for what we could have ended up with?  That all depends.

Let’s say the two allele variants for gene X are A and B.  If Dad had an AA pairing and Mom had a BB pairing, then our only possibility was an AB pairing.   However, if our Dad was AB and our Mom was BB, then we’d have 2 possible choices:  AB or BB.  And it would be a 50-50 chance that we got either one. 

Now, if both our parents were AB, then we’d have 3 choices (note that AB=BA) but they are not all equally likely.   There’s only 1 AA and only 1 BB, but there are 2 AB’s.  So there is a 25% chance of AA, a 25% chance of BB, and a 50% chance of AB.  

If it turns out that the A allele is dominant, then from the outside we’d not be able to tell the difference between someone with AA vs. someone with AB.  Only the BB’s would show any signs.  Again, this is no biggy with something as silly as eye color or handedness, but when it comes to diseases or something life threatening, it certainly is.

Times Have Changed

Back in ye-olden days, sometime after Darwin did the damage, it was thought that a dominant gene variant, or allele, would, given enough time, simply wipe out a recessive one.  It seemed reasonable at the time.  If there is a negative selection value for a particular trait, evolution should select it out.  That’s how Natural Selection works, right?

Well, no.  As the above calculations show, life ain’t that simple.  If two members of a population have that AB type, where B is a deleterious (or “bad for you”) allele.  Then, there is a 1/4 probability that they will have a child with the negative BB variation. 

In other words, no matter how bad a trait can be, it can never be wiped out unless you killed off all of the AB’s along with the BB’s.   But, since the AB’s don’t exhibit the negative trait, nature won’t “know” to select them out.  They pass the test. 

Back to Wisdom Teeth

WisdomTeeth Given this new information, we can answer the question posed at the beginning with some confidence.  Even though it is totally true that having wisdom teeth grow in in a prehistoric village can spell death (via infection and impaction), it would not do so until after the person reached breeding age.  In fact, wisdom teeth often don’t show up until the early twenties or later.  By then, the person could have had multiple children.

So, if there was breeding going on between these populations (the one without wisdom teeth, and the one with them) then there would have been a lot of mixing.

Even if the first was all AA’s which coded for NO wisdom teeth, and the other was all BB’s which coded for them.  And we allowed the A to be dominant, then we’d still see a ton of variation in both villages.  AA x BB = AB at least half the time.  And then AB x AB = BB 25% of the time.  In just 2 generations you’d have signs of wisdom teeth.  In a few more it would grow since AB x BB = BB 50% of the time. 

Disclaimer

I want to just make one last point.  When I’ve been using the word gene, I mean that almost metaphorically.  It could be that there’s a single gene for eye color (there isn’t), but that isn’t the point.  The point is that there is a gene, or a collection of genes, that code for a trait.  And that there are variants of that gene, or collection of genes, called alleles.  These different alleles combine to give us an array of possibilities.  Whether the trait we’re looking at is coded for by a single gene or a collection is often glossed over because it doesn’t actually make much of a difference from that standpoint.  But, it can seem confusing sometimes to hear “gene” but really be thinking of a collection of genes that work together. 

Native American Rights to Anthropological Finds


The North American Graves and Repatriation Act (NAGRA) is being amended.  This is the act, set in 1990, that made it possible for Native American tribes to exert claims over human bones found that had “cultural” significance.  I put “cultural” in quotes because it’s been a point of contention as to what exactly we mean by that.

Following years of pressure from Native American groups, the new rule
would give them the right to claim specimens without a cultural link if
they had been found close to tribes’ historic lands. “This is a major
departure, going way beyond the intent of the original law,” says John
O’Shea, a curator at the University of Michigan Museum of Anthropology
in Ann Arbor, which has about 1,400 specimens considered culturally
unaffiliated. Overall, there are more than 124,000 culturally
unidentified ancient human remains in US institutions; although
estimates vary widely, at least 15% of these could be affected by the
new rule.

Now they don’t even need a cultural link.  If bones from someone living 2000 years ago are found near tribal historic lands, they can be claimed.  That’s like me stopping an excavation of a Roman site on the grounds of it being close to my “tribe’s” historic lands. 

I was against much of what is in this act all along, but now I’m just blown away.  I understand that if there is a clear and obvious cultural link to a set of remains, then a tribe should get rights over it (it’s like if someone wanted to dig up George Washington’s remains, lot’s of Americans would be mad).  If the remains are recent (last few hundred years), or are clearly from a still active culture, then leave them alone.

But, come on.  At some point, science has to be done.  My families roots are from Scotland.  This is where some of the more famous “Bog Bodies” have been found.  Should I file a complaint that someone dug up my ancestor and that it violates my cultural tradition?

In my opinion, anything beyond 200 years should be fair game, I don’t care what your culture is.  So, if you want to dig up George Washington, or Thomas Jefferson to see if you can get any DNA off of them, be my guest.  Similarly, the only way to know about the prehistory of the people of North America is to do science on what we find.  We can’t do that if the bones get reburied. 

[By the way, the picture at the top of the page is NOT a Native American.  It’s a bog body found “near” where my ancestral lands were.]

Art and Science: Sketches of Anthropology


Both John Hawks and Carl Zimmer discuss the tension and the rewards that come out of the necessary artists renderings of scientific discoveries.  Hawks post is here, and Zimmer’s is here.

Just think — how many reconstructions of Neandertals have you seen in the last few years that weren’t red-headed? Gurche’s new one isn’t, but almost all have been. The red-headed Neandertal clearly conveys the information about the genomics of MC1R,
and yet the color itself is just a hypothesis. As I discussed upon the
discovery, even if the variant has the postulated functional effect on
melanocortin reception by melanocytes, there may well have been
modifier genes that made Neandertal hair blonde. The convention
of the red-headed Neandertal follows the needs of museums and textbook
authors, all of whom need to tell the story about genetics. But in that
sense, it’s rather like the convention of a bearded Jesus — making the
Neandertal iconic triggers our recognition, but may subtract the need
to scrutinize closely, to experience the form anew.

Kennewick Man is a great example (see above pic).  Based on the skull morphology it is highly likely that he looked like Captain Jean-Luc Picard of the Enterprise.  But, had the artist put a giant afro on his head, we may not have seen the connection.  The real Kennewick man could have had an afro, we don’t know for sure.  Maybe he had dreadlocks.  Long black hair?  It’s hard to say for sure.  But, the act of leaving the skull unadorned made him an icon. 

Clash of the Titans: Mature vs New Science

clash-of-the-titans

John Hawks takes a paragraph of a new book by William Burroughs, “Climate Change in Prehistory,” and runs with it.   It has to do with the clash between mature sciences and emerging new sciences.  Here’s the paragraph Hawks refers to:

It is often easier to write with confidence on fast-developing and relatively new areas of research, such as climate change and genetic mapping, than to review the implications of such new developments for a mature discipline like archaeology. Because the latter consists of an immensely complicated edifice that has been built up over a long time by the painstaking accumulation of fragmentary evidence from a vast array of sources, it is hard to define those aspects of the subject that are most affected by results obtained in a completely different discipline. Furthermore, when it comes to many aspects of prehistory, the field is full of controversy, into which the new data are not easily introduced. As a consequence, there is an inevitable tendency to gloss over these pitfalls and rely on secondary or even tertiary literature to provide an accessible backdrop against which new developments can be more easily projected (Burroughs 2005:10).

Hawks makes the point that this paragraph’s suggestion that a new science in facing resistance from an entrenched mature science can lead to one of two possible conclusions

1. … and therefore the simple conclusions of the immature sciences may be wrong.

or

2. … and therefore those wishy-washy archaeologists had better get their act together.

He comes to the defense of (what he calls) the mature science of archaeology.  In this defense he points out …

What marks a "mature" discipline is the emergence of informed critiques focused on the limits of methods of analysis. When archaeology was immature, before the 1950s or so, almost all archaeologists were simple (some say "naive") positivists. They excavated and found the traces of ancient people, just as today’s archaeologists do. And what they found was what there must have been. Find a handaxe, you know people made handaxes; find a temple, you know they worshipped gods of some kind. Dig in a mound, find a grave, you know that the people had rituals associated with death that required substantial non-subsistence directed labor.

Notice his definition of “mature”:  An emergence of informed critiques, focused on the limits of methods of analysis.  This isn’t a horrible definition (I’ll argue for a different one below).  He goes on:

Of course, today’s archaeologists tend to be positivists, too. There’s no sense twiddling around with hypotheses that will never be testable. The religion of Neandertals? Well, it’s one thing to speculate about it, but the fact is that it’s devilishly hard to test hypotheses about religion from the material remains of any pre-monumental culture. In the absence of information, we may as well stick to the facts.

But there’s a deeper sense in which archaeologists have a much more complicated view of their evidence. Archaeology has gone through many periods where different researchers developed and applied distinctive analytical techniques. These techniques have often been incommensurable. Sometimes they settle debates. For example, the systematic study of skeletal element representation and cutmark taphonomy has gone far toward testing (and verifying) the occurrence of hunting in some Early Pleistocene contexts. The hunting versus scavenging debate still goes on, with renewed emphasis on active or confrontational scavenging. But knowledge advanced by means of analytical critique.

 

 

What is a “Mature” Science?

Now, I don’t want to sound like a curmudgeon, but I would never call Archeology a mature science.  At least not by my definition (which I’ll outline in a second).  It is an adolescent science, albeit an exciting one on the verge of maturity. 

I define a field to be "mature" if and only if it has a reasonably well developed empirical AND theoretical side.  Without both, you are only half a science.   

(OK, I used the ambiguous word "reasonably" in my definition.  And this opens the door for questions about what we mean by that.  But, that’s the way laws should be written – with room for interpretation.)

I’ve found most people I talk to about this (in the sciences) to be rather hostile to my definition.  I suspect the reason is that if we take it to be strict, there is only ONE mature science – Physics.  (I include engineering in physics as applied-physics, the way that we include medicine in biology as applied-biology.)  The reason is that it is the only science that has serious mathematics and theoretical work being done “in house”.  They don’t rely on Mathematicians to do the hard labor for them.  There IS great work being done on the theoretical side of a lot of other sciences, but nearly all of it is done by Mathematicians and Physicists. 

Let’s go into more detail as to what I mean in my definition:

Empirical Science

chemistry

The empirical side of science is what everyone thinks of when they think of science.  That is, when YOU think “science”, I’m guessing that you’re thinking of guys in white lab coats pouring boiling blue liquid into a beaker.  This side of science is well developed in nearly every field save for economics (that’s a whole different discussion – and a strange one at that). 

This side of science is all about hypothesis testing, data collection, and statistical and other methods to deal with the vast amount of data that is gathered.  That is, this is the “get your hands dirty” part of science.  It’s why most people who go into science went in to it in the first place.  They loved all that went with it.  Primatologists love to hang out with primates, Chemists love to mix chemicals, Archaeologist love to dig in the dirt. 

As I discussed in my article on Karl Popper, a science must have a robust empirical side in order to test hypothesis.  Without it, we have no way to know if we’re just blowing smoke or not.

What most sciences don’t have (and some refuse to take seriously) is a serious theoretical side of their field. 

Theoretical Science

math

Theoretical Science is all about hypothesis generating.  Darwin’s theory of natural selection is an example of a work of theoretical science.  Einstein was a theoretical physicist, and the theory of relativity is a work of theoretical science also. 

As a field gets more developed, theoretical science converges more and more toward mathematical and computational work.  That is, the models become so complicated that only the tools of mathematics and computer science are able to deal with them.

Don’t get this confused with statistics.  We need complex statistical models to deal with the data collected by empirical scientists.  But, theoretical scientists don’t deal with data – at all.  Sure, they may be inspired by data.  But, the point is that they are developing theories about how the world works that are then able to be tested.    They follow lines of implication – if this is true, then this other thing MUST be true.  It is logical philosophy, mathematics, theorem-proof. 

No science is totally devoid of theory.  Obviously.  Paleoanthropologist gave us the “out of Africa” theory which has proven to be rather robust.  But, no science other than physics has a dedicated “in house” world of theoreticians who’s ONLY job is to follow lines of implications and thereby generate new and diverse hypothesis. 

Theoretical physics predicted Black holes before they were seen on a telescope.  They predict things like an expanding universe.  They predict dark matter, super strings, etc.  All of this is done by physicists who are not passed off by their empirical counterparts as “just” mathematicians, or “arm chair” physicists. 

They do their job with very complex mathematics.  Some times the experimental physicists will prove them right … sometimes wrong.   But, the important point is that they are full fledged members of the physics community. 

In most other sciences, theoretical (and especially mathematical) work is met with skepticism and sometimes outright disdain.  If you do ONLY theoretical work, then you are not really a member of this science at all … you’re a mathematician.  A real scientist DOES something.  They do field or lab work.  They get their hands dirty.  Blah, blah, blah …

Why Are Most Sciences So Hostile to Mathematics, and What Can We do About It?

I suspect the reason why most sciences have been traditionally so hostile to treating mathematical modeling as a serious part of their field is simply because most of the members of that science haven’t ever taken any serious math.  Oh, they may have taken a calculus class or two, but let’s get real.  Calculus is a FRESHMAN level class for math, physics, and engineering students.  There is an entire world of mathematics that comes after that that is hard to describe to people who haven’t seen it (imagine explaining what “red” means to a blind man).

Of course, this is changing.  Chemistry has always been in second place to Physics as the most mathematical of sciences.  They had to be.  Now Biology is catching up.  Theoretical Biology is (in my opinion), hands down, the most exciting emerging field (it’s been emerging for about 25 years).  But, still most of the work is done by math people, not biologists. 

What’s wrong with that?  Why not just let mathematicians do the work, and leave scientists alone to do the dirty stuff?

There are 2 reasons. 

  1. Mathematicians have their own work to do.
  2. Scientists and Mathematicians can’t communicate properly with one another.

First, contrary to popular belief amongst many scientists, Mathematicians are not here to serve you.  Yes, oftentimes they come up with highly useful tools that scientists find they can’t live without.  But, mathematicians generally get into math for its own sake … not because they care so much about furthering some particular science. 

Second, even amongst those mathematicians who DO get in on the action of a particular science, it’s often impossible for them to communicate with the members of said science.  This goes both ways.

Mathematicians are frustrated by the total lack of knowledge of even basic mathematical skill by scientists, and scientists are shocked at how little mathematicians know about the basics of their field. 

What physicists have figured out is that if you train your own theoreticians, then you can train them from the get-go to be able to communicate with the experimenters. They’ll know the big problems in the field, they’ll know the history, the language, the nuts and bolts.  Similarly, they train ALL physicists up to a threshold level of mathematical maturity, even the ones who become experimenters.  This way, everyone can talk to everyone else. 

So far, no other field has ever gotten this right.  They only train empirical scientists.  The only math required is what any advanced high school kid can do.  And as such, the theoretical side of their field is grossly underdeveloped. 

Again, this IS changing.  Most of the hard sciences are making strides fast, but it will take a lot more time. But, because of the reasons outlined above, I can’t call Archaeology a “mature” science.