Dobon et al. (2015) identified an ancestral autosomal component of West Eurasian origin that is common to many modern Sudanese Arabs, Nubians and Afroasiatic-speaking populations in the Nile Valley. Known as the Coptic component, it peaks among Egyptian Copts who settled in Sudan over the past two centuries. The scientists associate the Coptic component with Ancient Egyptian ancestry, without the later Arabian influence that is present among other Egyptians. Hollfelder et al. (2017) also analysed various populations in Sudan and similarly observed close autosomal affinities between their Sudanese Arab and Nubian samples.