|Newborn guinea pigs (Cavia porcellus)|
(c) Per Svendsen
Analysis of mitochondrial DNA (here and here) clearly shows that the domestic guinea pig groups with the montane species. Furthermore, analysis of the skeletons of mummified guinea pigs from archaeological sites in Southern Peru and Northern Chile (here) indicates that domestication started in the Andes, the natural habitat of C. tschudii.
|Karyotypes of Cavia tschudii male (left) and C. porcellus female (right)|
From Walker et al. 2014 (here) (c) Laura I. Walker et al.
Guinea pigs were imported by European traders in the 16th Century and underwent a second phase of domestication that resulted in the laboratory guinea pig. There was even a further phase of domestication in South America with two lineages of guinea pigs selected for improved meat quality.