Population dynamic of the extinct European aurochs: genetic evidence of a north-south differentiation pattern and no evidence of post-glacial expansion

Stefano Mona,Martina Lari,Giorgio Bertorelle,Giulio Catalano,Luca Sineo,Paolo Boscato,Antonella Casoli,David Caramelli,Elena Pecchioli,Carolina Di Patti,Greger Larson

doi:10.1186/1471-2148-10-83

Abstract

BackgroundThe aurochs (Bos primigenius) was a large bovine that ranged over almost the entirety of the Eurasian continent and North Africa. It is the wild ancestor of the modern cattle (Bos taurus), and went extinct in 1627 probably as a consequence of human hunting and the progressive reduction of its habitat. To investigate in detail the genetic history of this species and to compare the population dynamics in different European areas, we analysed Bos primigenius remains from various sites across Italy.ResultsFourteen samples provided ancient DNA fragments from the mitochondrial hypervariable region. Our data, jointly analysed with previously published sequences, support the view that Italian aurochsen were genetically similar to modern bovine breeds, but very different from northern/central European aurochsen. Bayesian analyses and coalescent simulations indicate that the genetic variation pattern in both Italian and northern/central European aurochsen is compatible with demographic stability after the last glaciation. We provide evidence that signatures of population expansion can erroneously arise in stable aurochsen populations when the different ages of the samples are not taken into account.ConclusionsDistinct groups of aurochsen probably inhabited Italy and northern/central Europe after the last glaciation, respectively. On the contrary, Italian and Fertile Crescent aurochsen likely shared several mtDNA sequences, now common in modern breeds. We argue that a certain level of genetic homogeneity characterized aurochs populations in Southern Europe and the Middle East, and also that post-glacial recolonization of northern and central Europe advanced, without major demographic expansions, from eastern, and not southern, refugia.

Highlights

The aurochs (Bos primigenius) was a large bovine that ranged over almost the entirety of the Eurasian continent and North Africa
The models differ in the relative contribution of the refugia populations to the expansion process, and the genetic data analysed for several species seemed always to fit the predictions of at least one of these models
The main goals of our study were: i) to investigate the genetic variability and the demographic history of Italian aurochsen, especially in comparison with the northern and central European groups; ii) to study whether and how the analysis of aurochs data collected at different time intervals may produce erroneous conclusions when simple statistics which assume simultaneous sampling are used; and iii) to test previous insights suggesting a role for the Palaeolithic aurochs in the domestication process in Italy [18]

Summary

Introduction

The aurochs (Bos primigenius) was a large bovine that ranged over almost the entirety of the Eurasian continent and North Africa. It is the wild ancestor of the modern cattle (Bos taurus), and went extinct in 1627 probably as a consequence of human hunting and the progressive reduction of its habitat. As a consequence of human hunting and habitat reduction [5], the aurochs went extinct in 1627, when the last individual died in Poland. The geographic distribution of genetic clusters might not always be informative for identifying recolonization routes

Objectives

Methods

Results

Discussion

Conclusion