TASK 3: Ancient DNA recovery

AIM: To recover ancient DNA samples of sufficient quality for subsequent genetic analyses, i.e. fine­scale phylochronological study (Task 4) of cattle in Iberia/North Africa, and to investigate their morphological changes and human­driven improvement over time (Task 5).

Analysis of ancient DNA will be conducted in the dedicated facility provided by A. Götherström, which will be crucial to avoid contamination and validate results.

We will follow specific protocols and take precautions to avoid contamination.

Reagents will be carefully selected for purity and applicability to ancient DNA research. Reagent­derived contamination can be a concern; and as needed we will use proper methods to decontaminate reagents (e.g. UV irradiation). Duplicate and independent ancient DNA samples will be extracted from each specimen, and two negative extraction controls will be included in every batch of 6 samples. Only results replicated at different levels will be considered for subsequent analyses.

Given our previous success rate in extracting ancient DNA from samples obtained in temperate/arid regions (~43%), we estimate to be able to recover DNA of sufficient quality from an additional ~130 samples.

The accomplishment of this task will allow for completing our ancient DNA bank representative of wild/domestic cattle from Iberia/North Africa (Milestone1), which will be available for subsequent analyses (Task 4 and Task 5) and also future studies.