Levallois technology in Nor Geghi 1, Armenia

From the paper:

Empirical evidence supports the contention that Levallois technology is an inherent property of the Acheulian that evolves out of the existing, but previously separate technological systems of façonnage and débitage (7, 35), and shows that Acheulian bifacial technology and Levallois technology are homologous, reflecting an ancestor-descendant relationship (36). Rather than a “technical breakthrough” that spread from a single point of origin, Levallois technology resulted from the gradual synthesis of stone knapping behaviors shared among hominins in Africa and those indigenous to the Acheulian dispersal area in Eurasia (Fig. 1). Consequently, the development of Levallois technology within Late Acheulian contexts represents instances of technological convergence.

Science 26 September 2014: Vol. 345 no. 6204 pp. 1609-1613 DOI: 10.1126/science.1256484

Early Levallois technology and the Lower to Middle Paleolithic transition in the Southern Caucasus 

D. S. Adler

ABSTRACT The Lower to Middle Paleolithic transition (~400,000 to 200,000 years ago) is marked by technical, behavioral, and anatomical changes among hominin populations throughout Africa and Eurasia. The replacement of bifacial stone tools, such as handaxes, by tools made on flakes detached from Levallois cores documents the most important conceptual shift in stone tool production strategies since the advent of bifacial technology more than one million years earlier and has been argued to result from the expansion of archaic Homo sapiens out of Africa. Our data from Nor Geghi 1, Armenia, record the earliest synchronic use of bifacial and Levallois technology outside Africa and are consistent with the hypothesis that this transition occurred independently within geographically dispersed, technologically precocious hominin populations with a shared technological ancestry.

Link

Gilbert on erectus, Klein on sapiens

This is a very interesting and information-rich talk by Henry Gilbert on Homo erectus and the Acheulean. A must-watch.

 

A second talk by Richard Klein on Homo sapiens and Out-of-Africa. Klein has featured in a mini-controversy regarding the recent evidence for archaic admixture in Africans, so it is interesting to get a concise overview of his opinions. I absolutely agree with him that "something big" happened at around 50,000 years ago, and I share his skepticism about signs of earlier behavioral modernity in Europe and Africa alike. I also agree with him that this "something" involved a migration of people. Where we part ways is that I do not share his conviction that this was an Out-of-Africa event. For several reasons:

• Eurasian mtDNA mega-haplogroups coalesce before 50ky
• Y-haplogroup CT coaelesces before 50ky, although some suggest (wrongly in my opinion) that it is of African origin
• Genetic divergence times between West Africans and Eurasians exceed 100ky; with hunter-gatherers they are even higher
• There is clear evidence of archaic admixture not only in Eurasians but also in Africans
• There does not seem to be clear temporal priority in any region with respect to the appearance of the 50ky Event

 

Brains to Hand-axes

Stone Age Humans Needed More Brain Power to Make Big Leap in Tool Design

Stone Age humans were only able to develop relatively advanced tools after their brains evolved a greater capacity for complex thought, according to a new study that investigates why it took early humans almost two million years to move from razor-sharp stones to a hand-held stone axe.

Wikipedia on Acheulean, and Oldowan.

PLoS ONE 5(11): e13718. doi:10.1371/journal.pone.0013718

The Manipulative Complexity of Lower Paleolithic Stone Toolmaking

Aldo Faisal et al.

Background
Early stone tools provide direct evidence of human cognitive and behavioral evolution that is otherwise unavailable. Proper interpretation of these data requires a robust interpretive framework linking archaeological evidence to specific behavioral and cognitive actions.

Methodology/Principal Findings
Here we employ a data glove to record manual joint angles in a modern experimental toolmaker (the 4th author) replicating ancient tool forms in order to characterize and compare the manipulative complexity of two major Lower Paleolithic technologies (Oldowan and Acheulean). To this end we used a principled and general measure of behavioral complexity based on the statistics of joint movements.

Conclusions/Significance
This allowed us to confirm that previously observed differences in brain activation associated with Oldowan versus Acheulean technologies reflect higher-level behavior organization rather than lower-level differences in manipulative complexity. This conclusion is consistent with a scenario in which the earliest stages of human technological evolution depended on novel perceptual-motor capacities (such as the control of joint stiffness) whereas later developments increasingly relied on enhanced mechanisms for cognitive control. This further suggests possible links between toolmaking and language evolution.

Link

Middle Stone age started 276,000 years ago

It is interesting that fairly modern tools were found so much earlier than previously thought. Whether anatomically modern humans existed back then is yet to be determined. This result shows that different levels of technological sophistication were to be found at the same point in time: mankind back then was not one species with one level of culture. And, indeed the earliest Homo sapiens, Omo I and II, were followed tens of thousands years later by Herto who was more "archaic" anatomically. Culture and anatomy do not go hand in hand.

Geology doi:10.1130/G25213A.1

Diachronous dawn of Africa's Middle Stone Age: New ⁴⁰Ar/³⁹Ar ages from the Ethiopian Rift

Leah E. Morgan1 and Paul R. Renne

Abstract

The Middle Stone Age (MSA) of Africa, like the Middle Paleolithic of Europe, is thought to represent a time period wherein toolmakers acquired significant increases in cognitive abilities and physical dexterity. Existing data fail to resolve whether the MSA emerged gradually, abruptly, or discontinuously, and whether this industry reflects the activity of Homo sapiens. Here we present new 40Ar/39Ar geochronological data revealing that advanced MSA archaeology at two sites in the main Ethiopian Rift is older than 276 ka, much older than technologically comparable MSA archaeology from elsewhere. An age of 183 ka for a unit farther upsection, along with the technological stasis observed throughout the section, indicates that similar technology was used here for ~93 ka. These results suggest that MSA technology evolved asynchronously in different places, and challenge the notion of a distinct time line for either the appearance of the MSA or the disappearance of the earlier Acheulean. These and other recent results indicate that the oldest known MSA consistently predates fossil evidence for the earliest Homo sapiens.

Link

Alan Templeton vs. Out of Africa with replacement: 1-0

Alan Templeton has followed up his work in Out of Africa again and again where he argued that the human genome holds evidence that is incompatible with an exclusively recent origin of modern humans. While human mtDNA and Y-chromosomes coalesce to a time less than 200ky and are thus contemporaneous with the emergence of anatomically modern humans, we also possess genes that are far older, and are best explained by the retention of ancestry from populations other than those emerging recently in the African continent.

Templeton used classical hypothesis testing to formally reject the Out of Africa with replacement model with a staggeringly low probability. It's possible that his procedure might be contested, but I just can't see how anyone can really support the replacement theory any more.

Templeton also believes that there were several Out of Africa movements, each of them leaving a "signature" in the genomic ancestry of modern humans. Different genes are dated to each of these three movements:



Templeton also finds that the three Out of Africa movements correlate quite well with archaeologically/anthropologically established movements:

These dates overlay well upon the fossil and archaeological record, with the first expansion corresponding to the original expansion of Homo erectus out of Africa into Eurasia (Aguirre and Carbonell, 2001; Bar-Yosef and Belfer-Cohen, 2001; Anto´n et al., 2002; Vekua et al., 2002) and the development of a culture capable of keeping impaired individuals alive for many years (Lordkipanidze et al., 2005). The second expansion corresponds to the spread of Acheulean culture into much of Eurasia after an earlier African origin (Asfaw et al., 1992; Hou et al., 2000) and the initiation of a substantial increase in cranial capacity (Ruff et al., 1997; Relethford, 2001b; Rightmire, 2004). The most recent expansion out of Africa corresponds to the spread of several anatomically modern traits into Eurasia after an earlier African origin (Stringer, 2002; White et al., 2003).

This certainly also seems to agree with Erik Trinkaus' recent statement:

Versions of the assimilation model have remained contenders for the interpretation of modern human phylogenetic emergence, if frequently overshadowed by the more polarized regional continuity (with gene flow) and (out of Africa with) replacement scenarios. The last two interpretations are finally intellectually dead. Both are contradicted by available evidence, and it is time for the discussion to move on. Yet, despite the general acceptance of some form of the assimilation model, issues remain.

Update... but Milford Wolpoff writes in the comments (which disappear after 4 months on Haloscan):

I just don't see how Templeton's excellent review somehow supports Trinkaus' comment. ET asserts that multiregional evolution is "finally intellectually dead" whereas Templeton describes an interpretation of human evolution that is compatible with multiregional evolution, as he has noted. Trinkaus would replace multiregional evolution with his "assimilation theory" - an interpretation that does not seem to differ from multiregional evolution except by name, which perhaps explains the problem.

New analysis shows three human migrations out of Africa (excerpt):

Feb. 2, 2006 — A new, more robust analysis of recently derived human gene trees by Alan R. Templeton, Ph.D, of Washington University in St Louis, shows three distinct major waves of human migration out of Africa instead of just two, and statistically refutes — strongly — the 'Out of Africa' replacement theory.

That theory holds that populations of Homo sapiens left Africa 100,000 years ago and wiped out existing populations of humans. Templeton has shown that the African populations interbred with the Eurasian populations — thus, making love, not war.

"The 'Out of Africa' replacement theory has always been a big controversy," Templeton said. "I set up a null hypothesis and the program rejected that hypothesis using the new data with a probability level of 10 to the minus 17th. In science, you don't get any more conclusive than that. It says that the hypothesis of no interbreeding is so grossly incompatible with the data, that you can reject it."

Templeton's analysis is considered to be the only definitive statistical test to refute the theory, dominant in human evolution science for more than two decades.

"Not only does the new analysis reject the theory, it demolishes it," Templeton said.

Templeton published his results in the Yearbook of Physical Anthropology, 2005.

American Journal of Physical Anthropology
Volume 128, Issue S41 , Pages 33 - 59

Haplotype Trees and Modern Human Origins (p 33-59)

Alan R. Templeton

Abstract

A haplotype is a multisite haploid genotype at two or more polymorphic sites on the same chromosome in a defined DNA region. An evolutionary tree of the haplotypes can be estimated if the DNA region had little to no recombination. Haplotype trees can be used to reconstruct past human gene-flow patterns and historical events, but any single tree captures only a small portion of evolutionary history, and is subject to error. A fuller view of human evolution requires multiple DNA regions, and errors can be minimized by cross-validating inferences across loci. An analysis of 25 DNA regions reveals an out-of-Africa expansion event at 1.9 million years ago. Gene flow with isolation by distance was established between African and Eurasian populations by about 1.5 million years ago, with no detectable interruptions since. A second out-of-Africa expansion occurred about 700,000 years ago, and involved interbreeding with at least some Eurasian populations. A third out-of-Africa event occurred around 100,000 years ago, and was also characterized by interbreeding, with the hypothesis of a total Eurasian replacement strongly rejected (P < 10-17). This does not preclude the possibility that some Eurasian populations could have been replaced, and the status of Neanderthals is indecisive. Demographic inferences from haplotype trees have been inconsistent, so few definitive conclusions can be made at this time. Haplotype trees from human parasites offer additional insights into human evolution and raise the possibility of an Asian isolate of humanity, but once again not in a definitive fashion. Haplotype trees can also indicate which genes were subject to positive selection in the lineage leading to modern humans. Genetics provides many insights into human evolution, but those insights need to be integrated with fossil and archaeological data to yield a fuller picture of the origin of modern humans.

Link