Original sentence: According to Gimbutas this Kurgan culture began spreading west between 4000-3500 BC.The Kurgan hypothesis has been based on linguistic and archaeological evidence
Edited sentence: According to Gimbutas this Kurgan culture began spreading west between 4000-3500 BC, which agrees tolerably well with the date suggested by linguistic evidence.The Kurgan hypothesis owes its popularity among linguists to the availability of archeological evidence, presented first by Marija Gimbutas, that corresponds well with the linguistic estimation of the date at which any set of related Indo-European languages must have begun diverging