Complex sentence: Knowledge of early human migrations, a major topic of archeology, has been achieved by the study of human fossils, occasionally by stone-age artifacts and more recently has been assisted by archaeogenetics cultural and ethnic migrations are estimated by combining archaeogenetics and comparative linguistics.
Split into simpler sentences: Knowledge of early human migrations, a major topic of archeology, has been achieved by the study of human fossils, occasionally by stone-age artifacts and more recently has been assisted by archaeogenetics. Cultural and ethnic migrations are estimated by combining archaeogenetics and comparative linguistics.