Colonization of the Scottish islands via long-distance Neolithic transport of red deer (Cervus elaphus).

David W G Stanton,Jacqueline A Mulville,Michael W Bruford

doi:10.1098/rspb.2016.0095

Abstract

Red deer (Cervus elaphus) have played a key role in human societies throughout history, with important cultural significance and as a source of food and materials. This relationship can be traced back to the earliest human cultures and continues to the present day. Humans are thought to be responsible for the movement of a considerable number of deer throughout history, although the majority of these movements are poorly described or understood. Studying such translocations allows us to better understand ancient human–wildlife interactions, and in the case of island colonizations, informs us about ancient human maritime practices. This study uses DNA sequences to characterise red deer genetic diversity across the Scottish islands (Inner and Outer Hebrides and Orkney) and mainland using ancient deer samples, and attempts to infer historical colonization events. We show that deer from the Outer Hebrides and Orkney are unlikely to have originated from mainland Scotland, implying that humans introduced red deer from a greater distance. Our results are also inconsistent with an origin from Ireland or Norway, suggesting long-distance maritime travel by Neolithic people to the outer Scottish Isles from an unknown source. Common haplotypes and low genetic differentiation between the Outer Hebrides and Orkney imply common ancestry and/or gene flow across these islands. Close genetic proximity between the Inner Hebrides and Ireland, however, corroborates previous studies identifying mainland Britain as a source for red deer introductions into Ireland. This study provides important information on the processes that led to the current distribution of the largest surviving indigenous land mammal in the British Isles.

Highlights

For at least the last 50 000 years, humans have played an important role in faunal redistribution [1,2], with early people moving animals for both food and cultural reasons [3]
There is evidence for the maritime colonization of Europe by Neolithic people of the Near East via the Mediterranean [5], with isolated long-distance sea travel around the Mediterranean as early as the Mesolithic [6]. There are fewer such examples of ancient sea travel in northern Europe, it is thought that humans introduced fur-bearing species to the Scottish Isles from the Neolithic onwards [7] and transported red deer (Cervus elaphus) from Britain to Ireland during the Irish Bronze Age [8]
This study aimed to describe the genetic diversity of ancient red deer populations on the Scottish islands, and compare this with other contemporary and modern red deer populations to infer details of historical red deer colonization

Summary

Introduction

For at least the last 50 000 years, humans have played an important role in faunal redistribution [1,2], with early people moving animals for both food and cultural reasons [3]. As red deer are thought to be able to swim up to 7 km [24] they could move from the mainland to the closer Inner Hebridean islands unaided, and this may explain their early occurrence Their ability to make the 25 km crossing from Skye to the Western Isles over the Miniches or 16 km across the Pentland Firth to Orkney is unlikely, humans probably facilitated their movement. We use partial mitochondrial 2 DNA (mtDNA) control region sequences isolated from insular and mainland Scottish red deer bone samples from between the Mesolithic and Norse Age to investigate this hypothesis. We attempted to extract and sequence mtDNA control region fragments of 74 ancient red deer samples from the Scottish mainland (n 1⁄4 7) and islands (Inner Hebrides, n 1⁄4 13; Orkney, n 1⁄4 17; Outer Hebrides, n 1⁄4 37). Genetic diversity indices (haplotype diversity and FST) were estimated using DNASP 5 [31] and ARLEQUIN 3.5 [32], respectively

Results

Orkney

Findings

Discussion