Lipid
residue study finds evidence for dramatic change in diet during Neolithic
transition
Agriculture reached Britain and
Ireland around 4000 BC, but the means by which the transition from hunting,
fishing and gathering occurred has been debated for many years. One view is
that indigenous Mesolithic people acquired domesticated crops and animals from
continental Europe, but retained much of their existing lifestyle. Another is
that Neolithic farmers arrived from the continent and spread rapidly. This
latter scenario proposes that a rapid acculturation of indigenous Mesolithic
people followed.
Previous work has considered stable
carbon isotope signatures of bone collagen extracted from Mesolithic and Neolithic
human remains. The results suggested that in coastal environments, the
Mesolithic diet included a significant amount of marine protein, but that of
the Neolithic farmers was predominantly terrestrial-based. However, doubts have
been expressed about the sensitivity of the bone collagen stable isotope
analysis to low-protein diets; quantities of less than 20 percent marine protein
in the diet would be undetectable. Possible Neolithic shell middens from
Scotland and Ireland suggest that seafood continued to be eaten.
To address this uncertainty,
researchers analysed lipid residues recovered from Neolithic pottery sherds
from coastal sites in Britain, the Scottish Isles, and Ireland. To extend the
chronological period, material was also included from sites dating to the
Bronze Age through to the Viking period. The results confirmed the near-complete
absence of marine protein from the Neolithic diet and the strong presence of
dairy products. This remained the case during the Bronze Age, and it was not until
Viking times did marine protein again become a significant dietary item.
Similar studies in the Baltic
region indicate a different pattern. There, hunting, gathering and fishing
continued alongside farming. The contrasting patterns occurring at the same
time in different regions suggest geographically-distinct ecological,
demographic and cultural influences dictating the adoption of agriculture. The
rapid shift to an intensive dairy economy is consistent with the low frequency
of lactose intolerance among modern inhabitants of northwest European
archipelagos. The evolutionary processes driving lactase persistence in adults would
have been driven by the increasing importance of dairy products in the diet.
References:
1. Cramp, L. et al.,
Immediate replacement of fishing with dairying by the earliest farmers of the
northeast Atlantic archipelagos. Proceedings of the Royal Society B 281
(2014).
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