A surprising link between tech change and evolutionary theory
Metalwork in the ancient Middle East can be described using concepts first developed by fossil hunters. Barry Keily reports.
Technological development during the Iron Age proceeded in sudden bursts rather than slow, gradual change, according to research into copper refining techniques used by the Edomite people, who lived in the area south of the Dead Sea in what is now modern-day Israel and Jordan.
Researchers led by Erez Ben-Yosef of Tel Aviv University in Israel gathered more than 150 samples of “slag”, the leftover product of copper refining, recovered from sites around a region known as Wadi Arabah, where the Edomites lived in predominantly semi-nomadic circumstances for many centuries.
The samples were firmly dated across a range spanning 1300 to 800 BCE. Analysing their composition provided clear indications of the types of technology used in production.
The results – published in the journal PLOS ONE – revealed that refining techniques tended to be stable, or at least modified only incrementally, for long periods, but were then rapidly replaced by newer methods.
The evidence, Ben-Yosef and colleagues realised, could be usefully described through a framework borrowed from evolutionary theory and known as “punctuated equilibrium”.
The idea was first advanced in 1972 by palaeontologists Stephen Jay Gould and Niles Eldredge, and was at first seen by many in the field as an impudent challenge to the orthodoxy of classical Darwinism.
Darwin suggested that evolution – the emergence of new species – was a slow and gradual process. Gould and Eldredge found that this idea did not accord with evidence arising from the fossil record.
Instead, they suggested, species tended to be pretty much stable entities for long periods of time, and evolved into new lineages primarily when faced with extreme challenges – in response to climatic or geological change at the edges of their distribution range, for instance.
Evolution, thus, proceeded in a series of sudden leaps rather than smoothly and slowly.
Punctuated evolution is today a solid and accepted mechanism within the field – and Ben-Yosef and colleagues find that a similar model can be deployed to account for technological advances, at least in the ancient Middle East.
Their research finds that three sudden changes in refining techniques coincide with major geopolitical shifts affecting the Edomite people, primarily concerning the successive arrival and withdrawal of Egyptian occupying forces. The last of these, which coincided with a major shift in refining techniques, occurred when the region fell under the control of the Egyptian ruler Shoshenq 1 in the Tenth Century BCE.
The researchers note, however, that during each of the periods of accelerated technological change, production never stopped – indicating that existing industry was never wiped out, but that new methods were phased in.
This, Ben-Yosef and colleagues note, strongly suggests that new ideas and techniques introduced by successive occupying forces was welcomed by, rather than forced upon, the Edomites.
“Thus, changes imposed or triggered by the Egyptian intervention at the time of Shoshenq I’s campaign resulted in unparalleled flourishing of the industry, rather than a catastrophic clash,” they write.