Fig. 1.

Identification of human accelerated elements. Top: the four different approaches used to identify human accelerated regions. Some key differences include (i) the conserved elements used as candidates to identify HARs (which depend on multiple sequence alignments, methods to detect conservation, and whether human was masked in the alignments), (ii) bioinformatics filters that aim to restrict to non-coding elements and/or remove assembly or alignment artifacts, and (iii) tests used to detect acceleration. Bottom: overlap of the different datasets of human accelerated regions. Abbreviations: ANC accelerated conserved non-coding sequences [20]; HACNS human accelerated conserved non-coding sequences [23]; HTBE human terminal branch elements [21]. HARs include the original HARs [19] and the second generation HARs or 2xHARs [100]