Original sentence: Alternatively, it has been suggested that R1a arrived in southern Scandinavia during the time of the Corded Ware culture.Haplogroup R1a1, a lineage thought to have originated in the Eurasian Steppes north of the Black and Caspian Seas, is associated with the Kurgan culture, as well as with the postglacial Ahrensburg culture which has been suggested to have spread the gene originally
Edited sentence: Another hypothesis, the gene could have arrived in southern Scandinavia during the time of the Corded Ware culture.Some other theories have associated the R1a1 lineage to have originated north of the Black and Caspian Seas, has been associated with the Kurgan culture, as well possibly with the postglacial Ahrensburg culture, which has been suggested where gene might have spread from originally