The recent announcement of the discovery in stone tools in Kenya dating to 3.3 million years ago (MYA) has been greeted with a lot of fanfare.  I first heard the story at some point earlier in the academic year, and I know there was a lot of buzz about it at the SAAs and Paleoanthropology meetings in San Francisco in April.  The publication of a formal paper in Nature last week (“3.3-Million-Year-Old Stone Tools From Lomekwi 3, West Turkana, Kenya,” by Sonia Harmand and colleagues) led to a flurry of stories in the popular media.  Many of those stories (for example this one in the L. A. Times) framed the discovery as one that "hints that anthropologists may have had the wrong idea about the evolution of humans and technology."

Spoiler alert:  The stone tools from Lomekwi 3 are an important finding, but not a surprising one.

Hyping and over-simplification by the popular media of scientific findings  are a fact of life, and I understand the need to find an "angle" for a summary story.  I find the media's coverage of the Lomekwi paper particularly annoying, however, because of the general implication that the discovery of tools of that age somehow caught us all by surprise.  It didn't.  Anyone who has been paying attention to the field for the last few decades will not be surprised at all by the claims that: (1) there are stone tools that pre-date Oldowan; (2) those tools were probably not made by members of the genus Homo; and (3) the use of stone tools can be traced back to at least 3.3 MYA.

Let me be clear:  this is a very important finding, just not a particularly surprising one.  The tool assemblage from Lomekwi 3 (LOM3) fits very comfortably within an emerging picture of tool use pre-dating Oldowan and Homo.  That picture has been coming into focus for decades now, thanks to a lot of hard work by many different scientists.  The LOM3 tools make a significant contribution to that picture by providing a line of direct evidence that was previously absent.  For the first time, we get some idea of what pre-Oldowan stone technologies might have been like.  I think it was only a matter of time, however, and there will be a lot more coming down the road.

Why did we expect stone tools pre-dating Oldowan to be found?

First, as pointed out in the LOM3 paper, the 3.3-million-year-old age of the tools is consistent with the 3.4 MYA cutmarked bones from Dikika, Ethiopia that were reported several years ago. Not everyone accepts those cutmarks as legitimate (here is a John Hawks' post about the critique), however.  I'm not a cutmark expert, so I don't really have a strong opinion.  I'll just say that finding a stone tool assemblage in east Africa that dates to the same time period as the purported cutmarks mitigates the "but where are the tools?" question for me.

Second, the idea that only humans use tools (and therefore evidence of tool use should only be associated with the genus Homo) is an antiquated one that has been solidly falsified by studying living, non-human primates.  The use of tools has been widely observed among wild chimpanzees, our closest living relative (and also among more distant relatives such as orangutans and gorillas).  The most parsimonious explanation for the presence of tool-using behaviors in chimpanzees and humans is that those behaviors were also present in the Last Common Ancestor (LCA).  If correct, that means that all hominids/hominins (as well as all members of the lineage leading to chimpanzees) had some capacity to make and use tools. If not correct, we need to explain the independent emergence of tool use in both lineages.  I think the first possibility (that the capacity to use tools is a homology) is more likely, and makes it much easier to explain the widespread use of tools among great apes and some other primates. The LOM3 assemblage pushes our understanding of a particular kind of tool use (stone tool use) back in time, but it is by no means at odds with the general idea that all hominids had the capacity to use tools.  It provides direct evidence, rather, to help evaluate hypotheses about the timing and nature of the evolution of tool-using behaviors that are peculiar to humans.

The presence of tool-using behaviors among several of our closest relatives suggests that the cognitive hardware required for tool use was present deep in the Great Ape lineage: it doesn't take a big, human-like brain to make and use simple tools. But what about other parts of our anatomy? 

One of the features of a human hand is the broad, flat distal phalanx of the thumb.  Because of our precision grip (enabled by our relatively short fingers), we are able to exert a lot of force between our thumb and forefinger. The broad bones at the ends of our thumbs reflect those strong forces.  The shape of the distal thumb bone of OH 7 was one of the criteria used to define Homo habilis in the original 1964 paper by Louis Leakey, Philip Tobias and J. R. Napier:

". . . the hand bones resemble those of Homo sapiens sapiens in the presence of broad, stout, terminal phalanges on fingers and thumb . . ." (Leakey et al. 1964:8).

As more fossil hands have been discovered in the decades that followed, it has become apparent that many hominids had "broad, stout, terminal phalanges" in their thumbs.  The illustration above (from Almécija et al. 2010) shows the OH 7 thumb bone compared to the thumb of Orrorin tugenensis (a possible hominid from around 6 MYA), a modern human, a chimpanzee, and a gorilla. Orrorin had a broad thumb.  What about robust australopithecines?  Yep. Australopithecus sediba?  Yep.  It looks like there were a lot of hominids that may have had good features for tool-using hands. If Ardipithecus ramidus (4.4 MYA) was a hominid, it suggests that a chimpanzee's hand is in fact more derived from the ancestral condition than a human hand:  the LCA's hand may have been "pre-adapted" for tool use with a pliable, mobile wrist.  All that was needed to make the transition to a human-like hand was to shorten the long fingers (which could have happened in the process of shifting to a fully terrestrial adaptation) and broaden the thumb as a precision grip became possible. If tool use was at all important to our pre-Homo ancestors, the selective pressure to shorten the fingers would have been present all along, just less constrained once long fingers were no longer needed for a partially arboreal adaptation.

So it looks like the cognitive capacity for tool use among our ancestors was probably present by at least the end of the Miocene (in the LCA), and the changes to hand anatomy that allowed human-like grasping were well underway during the Pliocene (ca. 5.3-2.6 MYA).  The discovery of stone tools dating to 3.3 MYA doesn't conflict with any lines of evidence that I know of suggesting when we could see the earliest stone tools.  The interesting questions that we can start address with the publication of the information from Lomekwi, really, are the "who" and the "why" questions: Why did hominids start making and using stone tools?  Which hominids were making these tools?  And what did tool use have to do with other aspects of human and hominid evolution?

Harmand et al. (2015:314) find differences between the lithic materials from LOM3 and Oldowan, and propose that the technology be given a new name: Lomekwian. 

"The LOM3 knapper's understanding of stone fracture mechanics and grammars of action is clearly less developed than that reflected in early Oldowan assemblages and neither were they predominantly using free-hand techniques. The LOM3 assemblage could represent a technological stage between a hypothetical pounding-oriented stone tool use by an earlier hominin and the flaking-oriented knapping behavior of later, Oldowan toolmakers."

The identification of "Lomekwian" tools is going to open up some new thinking about the roles of tool use in general (and stone tools in particular) in human and hominid evolution, not because stone tools at 3.3 MYA were unexpected, but because now we have some hard evidence of what those technologies might have been like. I don't work in Africa, but I'm probably not going too far out on a limb to suggest that there are plenty of places with mid- to late-Pliocene deposits that might be fertile ground for finding more direct evidence of these pre-Oldowan stone tool technologies.  It's going to be great to watch that story emerge.

I like aviation for several reasons.  For one, the history of aviation is a fascinating entanglement of history, technological change, and cultural transformation.  The century following the first powered flight in 1903 was one of immense change on many levels:  the development and growth of aviation articulated with economics, politics, conflict, communication, science, and many other aspects of that change.  Powered flight was and is a big deal.

That is my analytical interest.  On a more visceral level, flying and the technologies we use to fly exert an emotional gravity on me.  I just like airplanes.  Period. 

This weekend I went to the annual air show held at Willow Run Airport in Ypsilanti, Michigan. The “war bird” show at Willow Run traditionally leans toward World War II-era combat aircraft (both flying and on static display).  There were a lot of interesting things to see and think about at this show, both in terms of the aircraft that were present and the cultural dimensions of what was going on.   I can think of a few other kinds of events where large numbers of people gather to look at examples of obsolete technology (car shows come to mind first), but it is kind of an odd practice if you think about it.  Why does this happen?  What attracts us to celebrate specific classes of technological artifacts but not others?  It clearly isn’t just “impact factor:” the rise of computer/digital technology has had an astounding impact on the world, but we don’t gather annually to watch a TRS-80 saving a file to cassette tape or to listen to the hum of a Commodore 64 booting up (or maybe "we" do but I don't -- I'm prepared to be proven wrong on this).

Based on the conversations that I heard around me, many people at the air show weren’t there because they knew a lot of aviation history or cared about the technical specifics of what made a particular aircraft “interesting” or "significant." Sure, many people (myself included) probably were there at least partially because of some technical or historical interest.  But I think that air shows exist as a cultural phenomenon because people connect with something that is kinetic, dynamic, and beautiful in these machines.  Or at least some of these machines.  I’ll try to illustrate my point with a comparison of what I saw in the reaction of the crowd to two different aircraft: a B-17 (beautiful) and a B-24 (not beautiful).

The B-17 “Flying Fortress” (top schematic) and the B-24 “Liberator” (bottom schematic) were large, four-engine heavy bombers of World War II.  Both were very important in the narrative arc of the war.  I would say the B-17 is the better known of the two. One could argue, however, that the B-24 was more “important:” it was produced in significantly greater numbers than the B-17, was faster, and had a greater range. It was used in both theaters of the war.  The B-24 is an especially significant aircraft in terms of the cultural heritage of southeastern Michigan: the plant created to build the bomber at Willow Run was the largest industrial manufacturing facility in the world at the time and helped shaped the history and identity of this region.  This is the land of Rosie the Riveter and key elements of the Arsenal of Democracy.

Of over 18,000 built, there are only two remaining airworthy B-24s. One of them was at this year’s air show at Willow Run.  Seeing it fly was one of the reasons I went.  It flew. I saw it.  I expected to be thrilled, but I was not.  It was kind of boring.  I think many of those around me felt the same way. No matter how much excitement the announcer tried to drum up, it seemed to a lot of the crowd like a good time to visit the port-o-john or fetch more lemonade. Why?  Why did the sight of one of the last surviving examples of this immensely important aircraft produce such a big collective yawn?  I’ll tell you what I think:  I think it’s because it is ugly.  This aircraft is a collage of mismatched features that, while perhaps important to its functional characteristics, make it an aesthetic nightmare.  The long, slender wing (which helped the B-24 achieve its great range) is married to a fuselage that looks like a cement truck.  Somehow the aircraft appears both clunky and fragile, like it could break apart at any moment just from the stresses imposed by its own homeliness. It's ugly.

The B-17, in contrast, is a beautiful aircraft.  First flown in 1935, it is to aviation what the Chrysler Building is to architecture:  a bold Art Deco icon that exudes power, grace, solidity, symmetry, unity, modernity, purpose.  The aircraft that is flown by the Yankee Air Museum out of Willow Run is meticulously restored and polished, gleaming like a diamond.  The four large radial engines (each with 9 cylinders of 202 cubic inch displacement and 0 mufflers) produce a fantastic rumble that is audible from miles away.  The aircraft played an important role in history, but it is a crowd-pleaser because of the way it looks and sounds.  Because of the way it makes you feel.  Because it is beautiful. (Here is some video I put on YouTube  - it doesn't do the sound justice; you just have to hear it live).

I’m guessing many people have thought/written about the emotional connections (or lack thereof) between human cultures and their technologies, so I would be surprised if I’m saying anything new here.  It would be interesting to try to understand why we connect emotionally with some machines and not others, why some machines emerge as icons or symbols and some do not, and how that affects technological change.  It isn’t all in the historical significance or the minutia of what constitutes innovation or improvement.  Those things may play a role, but there are aspects of human cultural affection that I don’t think you can ignore.  Technological development is a human enterprise.

Finally, I’m sorry if I offended anyone by saying the B-24 is ugly.  But that’s my opinion and I’m sticking to it.  If it makes you feel any better, I think the Bell P-63 Kingcobra is even uglier.  There are only four of those left flying, one of which was at Willow Run this weekend.  Interesting aircraft with an interesting history; emotional appeal of concrete.

As I touched on in my discussion of this short paper in World Archaeology, I think the model-based study of patterns of change in historically-documented technologies can offer a lot of potential insight into patterns of change that we can identify in archaeological assemblages.  What, you might ask, can we possibly learn from the history of steam engines, cameras, microprocessors, and batteries that will help us understand changes in pre-industrial technologies?

My short answer is that we can: (1) look for common patterns of change and variability among these historically-documented  technologies; (2) attempt to understand the mechanisms underlying those patterns; and (3) try to develop expectations that will help us identify the mechanisms underlying technological change in prehistoric cases where we do not have documentary evidence.  The idea that the details of a particular system (e.g., a technological system) are often not as important to understanding the behavior of the system as one might guess is central to complex systems theory, and it is an idea that I subscribe to.  I think it’s a mistake to assume that technologies that we can observe in archaeological cases follow fundamentally different rules of change than those we can observe in the present or document historically (more on all that later when I finally get around to working on the Technological Change part of this website).

I’m currently reading George Basalla’s (1988) book entitled The Evolution of Technology.  One of the basic premises of this book is that “Any new thing that appears in the made world is based on some object already in existence” (Basalla 1988:45).  He is making an argument that technological change is fundamentally a continuous phenomenon and also asking the age-old question “where does innovation come from?”  I’m not deep into the book yet, but I’m finding it very satisfying so far.

Some of my favorite examples of technological change are related to aviation.  Since 1903 (the advent of powered flight) there has been an incredible amount of change in the design and performance of both aircraft and aircraft powerplants.  This change has been entangled with political, economic, and social change, global conflicts, and change in numerous “other” technologies.  As I’ve had time over the last few years, I’ve been collecting a large, dense dataset on aircraft and aircraft engines that I will be able to use as empirical example of technological change.   Up to now I’ve gathered data on over 1600 military aircraft (mostly fighters and bombers) and over 7000 engines.  I’ve still got a ways to go before I’m going to do any real analysis.  Eventually (as I publish) I’ll make those datasets freely available.

What does all this have to do with reverse-engineering of alien technology? As anyone who is paying attention to what passes for “history” on television these days will tell you, suggestions abound about extraterrestrial intervention in numerous aspects of human culture, history, technology, and biology.  In many cases these claims point to the “sudden appearance” of something as evidence of an extraterrestrial origin.  Contrary to Basalla’s (1988) continuity argument, the alien crowd asserts that (1) discontinuities in technology (i.e., the sudden appearance, without antecedent, of “advanced” technologies) can be identified and that (2) the most plausible explanation for those discontinuities is an extraterrestrial origin.  As an anthropologist and archaeologist, I get peeved by the ease with which people seem to swallow this nonsense.  The volume of “aliens” programming these days suggests that many people are watching, and, presumably, believing the garbage.   That’s a shame.  It is often fairly simple to debunk the “alien” claims using basic, easily available information.  This is especially true when the claim for extraterrestrial origin involves technology.  These are testable claims: showing continuity of technological development/change destroys the claim for discontinuity, and, consequently, the basis for asserting an alien origin.  And it's also fun.  And educational.

The B-2 bomber, a “flying wing” aircraft unveiled to the public in the late 1980s, is a modern machine which is said to incorporate alien technology: its unusual shape and the secrecy surrounding both its development and the technology used to make it a viable aircraft underlie those claims.   If the shape of the B-2 doesn’t look to you like any other “conventional” aircraft you’ve seen, you’re right.  It is one of only a small number of “flying wing” designs that have actually reached the flying stage.  The B-2 is clearly an outlier on a plot of the ratio of wingspan : length of over 600 bombers produced since World War I:  its wingspan is over twice its length, unlike any other contemporary fighter or bomber aircraft.   It also lacks a vertical tail surface.

Although the B-2 looks very different from other contemporary aircraft (as well as the vast majority of aircraft that preceded it), a quick look at aviation history shows that it did not simply arise out of nothing.  The history of “flying wing” aircraft designs, in fact, goes back to the very early years of powered flight.  J.W. Dunne was producing operational, swept wing, tail-less aircraft within just a few years of the Wright Brothers’ first flights (see this story in a 1910 issue of Flight and the photo at the top of this post).  The Horten brothers experimented with powered and unpowered “flying wing” aircraft during the 1930s and 1940s and produced a flying prototype (the Ho-229) that may have been produced in quantity if World War II had continued.  Northrop Grumman, maker of the B-2, produced numerous experimental and prototype “flying wing” aircraft during the 1940s.  If one were to plot the dimensions of these and other “flying wing” aircraft on the chart with the B-2, continuity would be apparent back to the early 1900s, when the proportions of Dunne’s aircraft fell within the range of variability of what was “conventional” at the time (see figure above). 

The proliferation of a technology or a technological system has practical, social, economic, cultural, and political dimensions, all of which may affect how it is perceived, used, developed, or perpetuated.  If “flying wing” designs are practical and have been studied and understood, why have "flying wing" aircraft never become commonplace?  Good question: from what I can tell, the answer involves a mixture of the factors listed above.  Understanding the interplay of those factors is an interesting problem.  We know for certain, however, that the B-2 does not represent a technological discontinuity.  It is one chapter in a history of human experimentation with “flying wing” aircraft that predates the advent of powered flight.  If we want to attribute the shape of the B-2 to a non-human origin, we have to go at least all the way back to Dunne to do it (maybe the aliens came down and told him to create a tail-less, swept-wing biplane).  Or (see this source) to the gliding properties of the seed pod of the Zanonia macrocarpa (a kind of gourd).  Aliens or gourd seeds . . .  Aliens or gourd seeds . . . hmmm, that really makes you think.