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Matt Ridley is the author of provocative books on evolution, genetics and society. His books have sold over a million copies, been translated into thirty languages, and have won several awards.

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Whether wild weather causes innovation

Neither Neanderthals nor a volatile climate caused innovation 42,000 years ago

On his blog, A Very Remote Period Indeed, Julien Riel-Salvatore discusses his recent paper about Neanderthals and innovation:

I'm quoted [in the press release] as saying, among other things, that this study helps 'rehabilitate' Neanderthals by showing that they were able to develop some of the accoutrements of behavioral modernity independent of any contact with modern humans. While I've caught a bit of flak from some friends and colleagues for that turn of phrase, I stand by my statement -this study helps to cast Neanderthals in a much more positive light than they have been for a long while now.

In my book, I argue that Neanderthals --though highly intelligent -- did not show a tendency to innovate, because they did not show a tendency to exchange (their artefacts never come from far away), and this kept their toolkit much the same till the end. The discovery of Neanderthals innovating would therefore be a blow to my argument.

I'm not yet convinced that the Uluzzian technology Riel-Salvatore describes was made by Neanderthals at all. Nor is he:

I'm the first one to admit that the fossil evidence for the 'transition interval' in Italy is extremely scant. The attribution of the proto-Aurignacian to modern humans is based on a couple of loose while the attribution of the Uluzzian to Neanderthals is based on three milk teeth from two layers in one site, Grotta del Cavallo. The only certainty seems to be for central Italy, where Neanderthal remains are associated with some of the Late Mousterian assemblages. In the past, the consensus view - no doubt in part informed by the Chatelperronian situation - has been that some of those teeth from Cavallo display some affinities to Neanderthals, in spite of the lowermost tooth originally having been described as more modern in appearance (Palma di Cesnola and Messeri 1967), although recent revisions suggest that it falls within the Neanderthal range (Churchill and Smith 2000).

Whatever the case may be, the fossil record is extremely thin here, and while people have traditionally been comfortable with the proto-Aurignacian = modern human and Uluzzian = Neanderthal equations, my own preference is to remain agnostic about who made what industry during the transition interval in the Italian peninsula (Riel-Salvatore 2009). However, because the generally accepted view is that the Uluzzian was made by Neanderthals, I've used it as an operating assumption in this new paper, even though I derive none of my hypotheses from that assumptions. In fact, I think that considering whoever made the Uluzzian first and foremost as foragers helps to avoid predetermining interpretations about what the Uluzzian was, how it came to be and how it disappeared.

Moreover, I don't find his argument for what triggered this burst of innovation persuasive. He blames it on an unusually volatile climate around 42,000 years ago:

Overall then, what I'm proposing in this paper is that climatic instability selected for behavioral innovation, one manifestation of which was the Uluzzian in southern Italy. If Neanderthals are responsible for the Uluzzian, that means they reacted in very 'modern' ways to these conditions by developing some of the very same innovations that seem to have made modern humans so evolutionary successful in the long ter

This meme just won't die. Even evolutionary biologists like it, arguing that the volatility of the Pleistocene in Africa selected for big brains in human beings -- even though it did not do so for any other mammal species. The actual empirical evidence for a volatile climate triggering innovation at any point in history or pre-history is non-existent. Places with the most volatile climate, like Australia, saw slow innovation rates, not fast. The settled climate that came after the ice age, not the wild swings of the last glacial maximum, caused a burst of innovation, especially in agriculture all over the world (see Richerson, Boyd and Bettinger's paper entitled `Was agriculture impossible during the Pleistocene but mandatory during the Holocene).

Until there is actual empirical evidence to the contrary, I will continue to think that the inventiveness of people comes from demographic density and frequent exchange, not from some fanciful climate determinant.

Oh, and until there is better evidence than three milk teeth I will continue to think that the Neadnderthals did not invent the Uluzzian technology.