Friday, 18 January 2019

Lagoa Santa skulls still perplex Danes

Peter Wilhelm Lund (1801-1880)
Danish National Library (public domain)
When Peter Lund excavated human remains from Sumidouro Cave he was thoroughly perplexed. Not least because they were jumbled together with the bones of an extinct megafauna. This was in 1840 so well before Darwin had published On the Origin of Species (which cites Lund's work).

The skeletons were shipped to Copenhagen and examined there by several distinguished anthropologists (Lund never returned to Denmark). The consensus that arose was that "Lagoa Santa Man" was unrelated to present-day Native Americans. 


Springer 2017: ISBN 978-3-319-57465-3
Research and debate was renewed in the last century with new excavations in the caves near Lagoa Santa (now a suburb of Belo Horisonte). A key find was Luzia, a skull feared lost in the recent fire at the National Museum in Rio de Janeiro (previous post) (it survived but suffered heat damage). This skull was dated to 11,000 years ago.

Comparisons have been drawn between the features of the Lagoa Santa skulls and those of Australasian peoples such as Andaman Islanders. What can genomics tell us? A first set of clues hinted at an early wave of migrants designated "Population Y" who left a genetic signature that is strongest in some isolated Brazilian communities (see my review of David Reich)


Skull from Sumidouro Cave excavated by Peter Lund
Now a Dane has ventured into the Lund Collection and extracted ancient DNA from a 10,400 year-old skull. The results appeared in Science last December (here). Eske Willeslev and his group found a clear Australasian genomic signature that was absent in other ancient remains from the Americas. They concluded this signal, "implies that an early group possessing it had disappeared or that a later-arriving group passed through North America without leaving any genetic trace." A conclusion echoed by the lead author, José Victor Moreno-Mayar, who simply said (here), "How did it get there? We have no idea."

It seems the Lagoa Santa remains are just as perplexing to Willerslev as they were to Lund and for a similar reason: they do not neatly fit into the scheme of things.

Postscript

The Willerslev paper is really worth reading. It builds on earlier work to confirm that Native Americans (other than Inuits) derived from a group that split from East Asians and resided in Beringia (Ancient Beringians). As they advanced into the Americas at the end of the Ice Age there was an early split into Northern (NNA) and Southern Native Americans (SNA). The SNA dispersed rapidly south of the remaining ice some 14,000 years ago. In a later phase there was admixture from a population in Mesoamerica that migrated both north and south. Another paper on ancient DNA from the Reich group also found evidence for rapid expansion into South America (here), but did not have Lagoa Santa in the data set.

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