Complex sentence: This group of dogs matches 3 fossil pre-Columbian New World dogs between 1,000 and 8,500 YBP, which supports the hypothesis that pre-Columbian dogs in the New World share ancestry with modern dogs and that they likely arrived with the first humans to the New World.
Split into simpler sentences: This group of dogs matches 3 fossil pre-Columbian New World dogs between 1,000 and 8,500 years old. Thus, these dogs likely arrived with the first humans to the New World.